JP5864235B2 - POWER SUPPLY DEVICE, ELECTRONIC DEVICE, AND METHOD FOR CONTROLLING POWER SUPPLY DEVICE - Google Patents

Description

  The present invention relates to a power supply apparatus that includes a plurality of rechargeable secondary batteries and supplies power to a load from any of the secondary batteries.

  In recent years, portable electronic devices such as mobile phones, smartphones, and notebook computers have become widespread. Such an electronic device includes a rechargeable secondary battery, and is driven by an output from the secondary battery when the power supplied from the outside cannot be used directly.

  Patent Document 1 discloses a power supply device including a power supply circuit driven by a commercial power supply and a rechargeable secondary battery. In Patent Document 1, in an electronic device that can be driven by either a commercial power source or a secondary battery, a power source circuit 11 that is driven by the commercial power source in the device body or apparatus, a rechargeable secondary battery 12, and the above A charging circuit 15 for charging the secondary battery by the output of the power supply circuit, and when the apparatus is driven by the power supply circuit 11 by an external AC power supply, the secondary battery is simultaneously driven by the charging circuit 15. 12 charging is described (summary, FIG. 1 etc.).

  Further, Patent Document 1 describes a power supply device that selectively drives a load 14 by a power supply circuit 11 and a pair of secondary batteries 31 (cell A31) and 32 (cell B32). , While switching the switching circuit 12 while driving the voltage, the load 14 is driven, that is, the load 14 is driven by either of the secondary batteries 31 and 32 (FIG. 3 and the like).

  In Patent Document 1, when the secondary batteries 31 and 32 have a memory effect, the discharged secondary batteries 31 and 32 can be completely discharged by a discharge resistor 36 to eliminate the memory effect. It is described that it becomes.

Japanese Patent Laying-Open No. 2004-23975 (released on January 22, 2004)

  However, Patent Document 1 does not specify the switching condition of each cell. Therefore, when charging and discharging are frequently switched, the number of times of charging / discharging the secondary battery is inadvertently increased. On the other hand, since the product life of the secondary battery is the limit number of charge / discharge cycles, when the number of charge / discharge of the secondary battery increases as described above, the product life of the secondary battery is shortened as a result. Occurs.

  Note that Patent Document 1 describes that when one or both of the cells 31 and 32 are not fully charged, a cell that is insufficiently charged is rapidly charged. Cause inadvertent increase.

  Moreover, in the technique disclosed in Patent Document 1, it may occur that the cell is connected to the load at the same time while being charged. In such a connection state, the charging current to the secondary battery cell is “charging circuit current—load current”. However, since the load current generally fluctuates, the charging current to the cell is unstable. become. Also, if a load greater than the current in the charging circuit is generated, the cell being charged turns and enters a discharged state. Such unstable charging causes the charge / discharge cycle life of the secondary battery cell to be shortened, and as a result, the product life of the secondary battery is shortened.

  The present invention has been made in view of the above-described problems, and its object is to provide a power supply device that suppresses the frequency with which a secondary battery is charged and discharged and suppresses the product life of the secondary battery from being shortened. There is to do.

  In order to solve the above-described problem, a power supply device according to the present invention includes a plurality of rechargeable secondary batteries and a charging unit that charges the secondary batteries, and loads from any of the plurality of secondary batteries. A power supply apparatus for supplying power to the battery, wherein one of the plurality of secondary batteries is connected to and disconnected from the charging unit, and one of the plurality of secondary batteries is connected to and disconnected from the load. The connection switching means connects the secondary battery connected to the load only to the load until the capacity reaches a predetermined lower limit value, and connects the secondary battery connected to the load. When the capacity reaches the lower limit, among the secondary batteries excluding the secondary battery, the secondary battery disconnected from the charging unit is connected to the load, and the capacity is The secondary battery that has reached the lower limit It is characterized in that to connect only the charging unit until capacity is reached highest.

  In order to solve the above-described problem, a control method for a power supply device according to the present invention includes a plurality of rechargeable secondary batteries and a charging unit that charges the secondary batteries. A method for controlling a power supply apparatus that feeds power to a load from any one of the power supply steps, wherein the secondary battery connected to the load is connected to only the load until the capacity reaches a predetermined lower limit value; When the capacity of the secondary battery connected to the load reaches the lower limit, among the secondary batteries excluding the secondary battery, one of the secondary batteries disconnected from the charging unit and the load And a connection switching step for connecting the secondary battery, and when the capacity of the secondary battery connected to the load reaches the lower limit value, the secondary battery is connected to only the charging unit until the capacity reaches the highest level. And including steps To have.

  According to said structure, the secondary battery connected with load is connected only with load until a capacity | capacitance reaches a predetermined | prescribed lower limit. And when the capacity | capacitance of the secondary battery connected with load reaches the said minimum value, among the secondary batteries except the said secondary battery, either of the said secondary batteries disconnected from the charging part and load are connected. Connect. Further, the secondary battery whose capacity has reached the lower limit value is connected only to the charging unit until the capacity reaches the highest level.

  Therefore, the secondary battery being supplied with power continues to be supplied and is not charged until the capacity reaches the lower limit. And when the capacity | capacitance of the said secondary battery reaches the said lower limit, it switches to the electric power feeding from the secondary battery which is not charging. Further, the secondary battery whose capacity has reached the lower limit value is charged until the capacity reaches the highest level and is not connected to the load.

  Therefore, the secondary battery being fed can be charged after being used until the capacity reaches the lower limit. Therefore, since the number of times of charge / discharge of the secondary battery can be reduced as compared with the conventional case, there is an effect that it is possible to extend the period until the predetermined number of charge / discharge cycles is reached.

  Further, since the secondary battery is not connected to the load during charging, the charging current is stabilized. Therefore, there is an effect that the charge / discharge cycle life (possible number of times) can be extended. Since the product life as a secondary battery is the limit number of charge / discharge cycles, the product life can be extended as a result.

  Furthermore, the power supply device according to the present invention further includes a storage unit that stores, for each secondary battery, the number of times that the secondary battery has been charged and discharged, and the connection switching unit further includes: When the capacity of the secondary battery connected to the load reaches the lower limit value, the charging unit that is disconnected from the charging unit and stored in the storage unit among the secondary batteries excluding the secondary battery is stored. The secondary battery with the minimum number of discharges may be connected to the load.

  According to said structure, when the capacity | capacitance of a secondary battery reaches the said lower limit, it switches to the electric power feeding from the secondary battery which is the secondary battery with the minimum charge / discharge frequency and is not charging.

  Therefore, when switching the secondary battery as the power supply source, the secondary battery with the smallest number of charge / discharge cycles is used with priority. Thereby, since the number of times of charging / discharging is averaged among the respective secondary batteries, it is realized as a whole power supply device that the period until the number of charging / discharging cycles of the secondary battery is reached is lengthened. As a result, the product life can be extended.

  Furthermore, in the power supply device according to the present invention, when the connection switching unit connects the secondary battery and the charging unit, charging / discharging of the connected secondary battery stored in the storage unit is performed. The number of times may be increased and updated.

  According to said structure, when a secondary battery and a charging part are connected, the frequency | count of charging / discharging of the connected secondary battery is increased by one, and is updated.

  Therefore, the charging / discharging frequency of the secondary battery can be increased by one at the timing of starting charging of the secondary battery.

  Therefore, when the secondary battery of the power supply source is switched next time, there is an effect that an appropriate secondary battery of the power supply source can be selected based on the updated number of times of charging / discharging.

  Furthermore, in the power supply device according to the present invention, when the connection switching unit connects the secondary battery and the load, the number of times of charge / discharge of the connected secondary battery stored in the storage unit is May be configured to be updated by one.

  According to said structure, when a secondary battery and a load are connected, the frequency | count of charging / discharging of the connected secondary battery is increased by one, and is updated.

  Therefore, the charging / discharging frequency of the secondary battery can be increased by one at the timing of starting power feeding from the secondary battery.

  Therefore, when the secondary battery of the power supply source is switched next time, there is an effect that an appropriate secondary battery of the power supply source can be selected based on the updated number of times of charging / discharging.

  Furthermore, in the power supply device according to the present invention, when all the capacities of the plurality of secondary batteries are the highest, the connection switching unit is configured such that the secondary battery with the smallest number of charge / discharge cycles stored in the storage unit is provided. The battery and the load may be connected and the charging unit may not be connected to any of the plurality of secondary batteries.

  According to said structure, when the capacity | capacitance of all the secondary batteries is the highest rank, while connecting the secondary battery and load with the minimum frequency | count of charging / discharging, not all the secondary batteries are charged.

  Therefore, when all the capacities of the plurality of secondary batteries are the highest, the secondary battery with the smallest number of charge / discharge cycles is used preferentially, so that the entire device reaches the predetermined number of charge / discharge cycles. There is an effect that the period up to can be extended.

  Furthermore, in the power supply device according to the present invention, when all of the plurality of secondary batteries have a capacity equal to or lower than the lower limit value and are not connected to the charging unit, the connection switching unit includes the storage unit. And connecting the secondary battery with the smallest number of charge / discharge cycles to the charging unit until the capacity reaches the highest level, and not connecting the load to any of the plurality of secondary batteries, When the capacity of the secondary battery connected to the charging unit reaches the highest level, the secondary battery may be connected to only the load.

  According to said structure, when the capacity | capacitance of all the secondary batteries is below the said lower limit, and it is not charging, it supplies electric power until the capacity | capacitance reaches the highest rank for the secondary battery with the minimum charge / discharge frequency. Charge without. Thereafter, when the capacity of the secondary battery reaches the highest level, the secondary battery is connected to the load without being charged.

  Therefore, when the capacities of all the secondary batteries are below the above lower limit value and are not being charged, the secondary battery with the smallest number of charge / discharge cycles is used after being charged preferentially. There is an effect that it is possible to extend the period until the predetermined number of charge / discharge cycles is reached.

  Furthermore, the power supply device according to the present invention further includes a discharging unit that discharges the connected secondary battery, and the connection switching unit further includes a connection between any one of the plurality of secondary batteries and the discharging unit. The connection switching means is configured to connect the secondary battery to be connected to the discharge means until the capacity is exhausted before connecting the secondary battery and the charging unit. May be.

  According to said structure, before connecting a secondary battery and a charging part, the said secondary battery to be connected is discharged until capacity is lost.

  Therefore, even when the capacity of the secondary battery remains, it can be charged after being discharged until the capacity is exhausted.

  Therefore, even when a secondary battery that cannot be recharged due to the memory effect such as a nickel cadmium battery is adopted in the present invention because the battery is not charged in a state where the capacity remains, the memory effect The effect that generation | occurrence | production of can be suppressed is produced.

  Note that an electronic apparatus including the power supply device and a load fed from the power supply device also falls within the scope of the present invention.

  As described above, the power supply device according to the present invention includes a plurality of rechargeable secondary batteries and a charging unit that charges the secondary batteries, and the load from any of the plurality of secondary batteries to the load. A power supply device for supplying power, wherein connection switching is performed to connect and disconnect any of the plurality of secondary batteries and the charging unit, and to connect and disconnect any of the plurality of secondary batteries and the load. The connection switching means connects the secondary battery connected to the load only to the load until the capacity reaches a predetermined lower limit, and the capacity of the secondary battery connected to the load is When the lower limit is reached, among the secondary batteries excluding the secondary battery, one of the secondary batteries disconnected from the charging unit is connected to the load, and the capacity reaches the lower limit. The above-mentioned secondary battery has the highest capacity Until it is connected to only the charging unit.

  Moreover, the control method of the power supply device according to the present invention includes a plurality of rechargeable secondary batteries and a charging unit that charges the secondary battery, and supplies power to the load from any of the plurality of secondary batteries. The method of controlling the power supply apparatus performs the power supply step of connecting the secondary battery connected to the load only to the load until the capacity reaches a predetermined lower limit, and the secondary battery connected to the load. A connection switching step of connecting any one of the secondary batteries disconnected from the charging unit to the load and the load when the capacity of the battery reaches the lower limit. When the capacity of the secondary battery connected to the load reaches the lower limit value, the charging step includes connecting the secondary battery only to the charging unit until the capacity reaches the highest level.

  Therefore, the secondary battery that is being fed continues to be fed without being charged until the capacity reaches the lower limit value, and is not being charged when the capacity of the secondary battery reaches the lower limit value. Switch to power supply from. Furthermore, the secondary battery whose capacity has reached the lower limit is charged without being connected to the load until the capacity reaches the highest level.

  Therefore, since the frequency of charge / discharge of the secondary battery is reduced as compared with the conventional case, there is an effect that it is possible to extend the period until the predetermined number of charge / discharge cycles is reached. Further, since the secondary battery is not connected to the load during charging, the charging current is stabilized, so that the product life can be extended.

It is a block diagram which shows the structure of the power supply device which concerns on one Embodiment of this invention. 2 is a flowchart showing a processing flow in the case where all the secondary batteries are fully charged in the power supply device shown in FIG. 1 in an initial state. In the power supply device shown in FIG. 1, the initial state is when power is supplied from one secondary battery, the secondary battery is in the middle of capacity, and the other secondary battery is fully charged. It is a flowchart which shows the flow of the process in a case. In the power supply device shown in FIG. 1, a flowchart showing a flow of processing in a case where one secondary battery has a lower capacity and the other secondary battery is fully charged or has a middle capacity. It is. In the power supply device shown in FIG. 1, the initial state is when power is supplied from one secondary battery, the secondary battery is in the middle of capacity, and the other secondary battery is fully charged. It is a flowchart which shows the flow of the process in a case. 6 (a) and 6 (b) show a case where, in the power supply device shown in FIG. 1, power is being supplied from one of the secondary batteries, and the case where any of the secondary batteries is in the middle of capacity is the initial state. It is a flowchart which shows the flow of the process in. In the power supply device shown in FIG. 1, a flowchart showing a flow of processing in a case where one secondary battery is fully charged or medium in capacity and the other secondary battery is in a lower capacity. It is. 2 is a flowchart showing a flow of processing in the case where all the secondary batteries have a lower capacity in an initial state in the power supply device shown in FIG. 1. In the power supply device shown in FIG. 1, the initial state is when power is supplied from one secondary battery, the secondary battery is in the middle of capacity, and the other secondary battery is fully charged. It is a flowchart which shows an example of the flow of the process in a case. It is a figure which shows the state and transition of the connection destination of a switching part in each step of the flowchart shown in FIG. It is a block diagram which shows the structure of the power supply device which concerns on other one Embodiment of this invention. 12 is a flowchart showing a flow of processing in the case where all the secondary batteries are fully charged in the power supply device shown in FIG. 11 in an initial state. In the power supply device shown in FIG. 11, the initial state is when power is being supplied from one secondary battery, the secondary battery is in the middle of capacity, and the other secondary battery is fully charged. It is a flowchart which shows the flow of the process in a case. In the power supply device shown in FIG. 11, a flowchart showing a flow of processing in a case where one secondary battery has a lower capacity and the other secondary battery is fully charged or has a middle capacity. It is. In the power supply device shown in FIG. 11, the initial state is when power is being supplied from one secondary battery, the secondary battery is in the middle of capacity, and the other secondary battery is fully charged. It is a flowchart which shows the flow of the process in a case. 16 (a) and 16 (b) show a case where, in the power supply device shown in FIG. 11, power is being supplied from one of the secondary batteries, and the case where any of the secondary batteries is in the middle of capacity is the initial state. It is a flowchart which shows the flow of the process in. In the power supply device shown in FIG. 11, a flowchart showing a processing flow when one of the secondary batteries is fully charged or medium in capacity and the other secondary battery is in the lower capacity. It is. 12 is a flowchart showing a flow of processing in the case where all the secondary batteries have a lower capacity in an initial state in the power supply device shown in FIG. In the power supply device shown in FIG. 11, the initial state is when power is being supplied from one secondary battery, the secondary battery is in the middle of capacity, and the other secondary battery is fully charged. It is a flowchart which shows an example of the flow of the process in a case. It is a figure which shows the state and transition of the connection destination of a switching part in each step of the flowchart shown in FIG. It is a block diagram which shows the structure of the power supply device which concerns on another one Embodiment of this invention. In the power supply device shown in FIG. 21, power is being supplied from one secondary battery, the secondary battery is in the middle of capacity, and the other secondary battery is fully charged. It is a flowchart which shows an example of the flow of the process in a case. It is a figure which shows the state and transition of the connection destination of a switching part in each step of the flowchart shown in FIG.

  The power supply device according to each embodiment includes a plurality of rechargeable secondary batteries, and when a power source supplied from the outside such as a commercial power source cannot be directly used, the secondary battery can be loaded from any of the secondary batteries. It is a device that supplies power. The power supply device is preferably mounted on an electronic device such as a mobile phone, a smartphone, or a laptop computer, but is not limited thereto.

  In each embodiment, a state in which the battery capacity of the secondary battery is the highest is expressed as “full charge”. A state in which the battery capacity of the secondary battery is equal to or lower than a lower limit value (hereinafter also referred to as “capacity lower limit”) that can be used in actual use is referred to as “capacity lower”. A state in which the battery capacity of the secondary battery is less than full charge and greater than the lower limit of capacity is referred to as “capacity middle”.

  In each embodiment, “number of times of charging / discharging” is expressed as meaning “the total number of times the secondary battery has been charged and the number of times the secondary battery has been discharged”.

Embodiment 1
An embodiment of the present invention will be described below with reference to FIGS. In this embodiment, in order to facilitate understanding of the present invention, an embodiment including two secondary batteries will be described. However, the number of secondary batteries is not limited to two.

(Configuration of power supply)
The configuration of the power supply device 10 according to the present embodiment will be described with reference to FIG. FIG. 1 is a block diagram showing an outline of the configuration of the power supply apparatus 10. As shown in the figure, the power supply device 10 includes a secondary battery A110, a secondary battery B111, a charging circuit unit (charging unit) 100, a connection switching control unit (connection switching unit) 102, a battery state monitoring unit 103, a charger. An I / F 104, a switching unit 105, a switching unit 106, and a storage unit 107 are provided. However, the storage unit 107 is not necessarily provided. Note that the connection switching control unit 102 and the battery state monitoring unit 103 may be configured as hardware by a logic circuit, or part or all of them may be realized by software using a CPU (central processing unit).

  In the figure, it is assumed that the power supply device 10 is mounted on the electronic device 1 including the device operating unit 101. The device operation unit 101 is a main system unit that executes various functions of the electronic device 1, and is a load when viewed from the power supply device 10. For example, when the electronic device 1 is a mobile phone, the device operation unit 101 executes various functions such as a call function, a communication function, and an imaging function.

  Secondary battery A110 and secondary battery B111 are rechargeable batteries such as lithium ion batteries.

  Next, the charging circuit unit 100 has a function of performing appropriate charging control such as constant current charging, constant voltage charging, and trickle charging. The charging circuit unit 100 is connected to a charger (not shown) via the charger I / F 104 and externally connected to the secondary battery via the switching unit 105. The charging control is performed on the connected secondary battery by the power supplied from.

  Next, the connection switching control unit 102 controls the switching unit 105 and the switching unit 106. Switching unit based on the remaining capacity of secondary battery A110 and secondary battery B111 detected by battery state monitoring unit 103 and the number of times of charging / discharging of secondary battery A110 and secondary battery B111 stored in storage unit 107 A configuration for controlling 105 and the switching unit 106 is preferable. Details of the control contents will be described later.

  When the storage unit 107 is provided, the connection switching control unit 102 stores the secondary battery stored in the storage unit 107 when the secondary battery and the charging circuit unit 100 are connected. Update the charging / discharging count by one. When the secondary battery and the device operation unit 101 are connected, the charge / discharge count of the connected secondary battery stored in the storage unit 107 may be updated by one.

  Next, the battery state monitoring unit 103 constantly monitors the secondary battery A110 and the secondary battery B111, and uses the integrated values of the battery voltage and the charge / discharge current to keep the secondary battery A110 and the secondary battery B111 remaining. Calculate capacity. The battery state monitoring unit 103 is at least (1) fully charged for each of the secondary battery A110 and the secondary battery B111, (2) the remaining capacity is lower than the capacity (lower than the capacity lower limit), (3) Detect that the remaining capacity is medium capacity.

  Next, the charger I / F 104 is an interface that connects the charging circuit unit 100 and the charger. A connector is usually used as the interface, but the interface is not limited to this, and a dedicated contact, a non-contact charging mechanism, or the like may be used.

  Next, the switching unit 105 is controlled by the connection switching control unit 102, and performs charging path selection and path disconnection switching. More specifically, the switching unit 105 (1) connects the charging circuit unit 100 and the secondary battery A110, (2) connects the charging circuit unit 100 and the secondary battery B111, and (3) the charging circuit unit 100. Is not connected to the secondary battery A110 or the secondary battery B111 (in other words, the connection between the charging circuit unit 100 and the secondary battery is disconnected).

  Similarly, the switching unit 106 is controlled by the connection switching control unit 102 and performs power supply route selection and route disconnection switching. More specifically, the switching unit 106 (1) connects the secondary battery A110 and the device operating unit 101, (2) connects the secondary battery B111 and the device operating unit 101, and (3) the device operating unit 101. Is not connected to the secondary battery A110 or the secondary battery B111 (in other words, the connection between the device operating unit 101 and the secondary battery is disconnected).

  Finally, the memory | storage part 107 memorize | stores the frequency | count of charging / discharging of each of secondary battery A110 and secondary battery B111, for example, is comprised by memory | storage devices, such as EEPROM (electrically erasable programmable read-only memory).

(Details of connection switching control)
When the charger is connected, the connection switching control unit 102 controls the switching unit 105 and the switching unit 106 so as to perform power feeding and charging as in cases 1 to 9 shown below.

(Case 1)
Case 1 is a case where all the secondary batteries are fully charged. In Case 1, the connection switching control unit 102 controls the switching unit 106 so as to start feeding from any of the secondary batteries. If the storage unit 107 is not provided, any secondary battery may be selected. On the other hand, when the storage unit 107 is provided, the charging / discharging frequency of each secondary battery stored in the storage unit 107 is referred to and power supply is started from the secondary battery having the minimum charging / discharging frequency. In either case, neither secondary battery is charged.

  The flow of processing in case 1 will be described with reference to FIG. FIG. 2 is a flowchart showing the flow of processing in case 1. Here, a case where the storage unit 107 is provided will be described.

  First, when the battery state monitoring unit 103 detects that both the secondary battery A110 and the secondary battery B111 are fully charged, the flowchart shown in FIG. 2 is started. Next, the connection switching control unit 102 refers to the number of times of charging / discharging of the secondary battery A110 and the secondary battery B111 stored in the storage unit 107 (step S (hereinafter also simply referred to as “S”) 11). .

  When the secondary battery A110 has a smaller number of charge / discharge cycles ("A is minimum" in S11), the connection switching control unit 102 switches the switching unit 106 so as to connect the secondary battery A110 and the device operation unit 101. To control. Thus, power is supplied from the secondary battery A110 to the device operating unit 101 (S12). In addition, after step S12, it is equivalent to the initial state of case 2.

  On the other hand, when secondary battery B111 has a smaller number of charge / discharge cycles ("B is minimum" in S11), connection switching control unit 102 switches switching unit 106 to connect secondary battery B111 and device operating unit 101. To control. Thus, power is supplied from the secondary battery B111 to the device operating unit 101 (S13). In addition, after step S13, it is equivalent to the initial state of case 4.

(Case 2)
Case 2 is a case where power is being supplied from the secondary battery A110 to the device operating unit 101, the secondary battery A110 is in the middle of capacity, and the secondary battery B111 is fully charged. is there. In Case 2, the power supply from the secondary battery A110 is maintained without charging the secondary battery A110 until the secondary battery A110 becomes lower in capacity. When the secondary battery A110 becomes lower in capacity, the power supply is switched from the secondary battery B111, and then the secondary battery A110 is charged.

  The flow of processing in case 2 will be described with reference to FIG. FIG. 3 is a flowchart showing the flow of processing in case 2. First, the switching unit 106 is controlled so that the secondary battery A110 and the device operating unit 101 are connected, and power is being supplied from the secondary battery A110 to the device operating unit 101 (S21).

  Step S22 (power feeding step) is repeated until the battery state monitoring unit 103 detects that the remaining capacity of the secondary battery A110 is equal to or lower than the lower limit of capacity (NO in S22).

  On the other hand, when the battery state monitoring unit 103 detects that the remaining capacity of the secondary battery A110 is equal to or lower than the lower limit of capacity (YES in S22), the connection switching control unit 102 connects the secondary battery B111 and the device operation unit 101 to each other. The switching unit 106 is controlled to connect. Thus, power is supplied from the secondary battery B111 to the device operating unit 101 (S23 (connection switching step)).

  Subsequently, the connection switching control unit 102 controls the switching unit 105 to connect the charging circuit unit 100 and the secondary battery A110. Thereby, the secondary battery A110 is charged (S24 (charging step)). In addition, after step S24, it is equivalent to the initial state of case 3.

(Case 3)
Case 3 is a case where the secondary battery A110 has a lower capacity and the secondary battery B111 is fully charged. In case 3, power is supplied from the secondary battery B111, and the secondary battery A110 is charged until full charge is reached. Note that power is not supplied from the secondary battery A110 until full charge is reached.

  The flow of processing in case 3 will be described with reference to FIG. FIG. 4 is a flowchart showing the flow of processing in case 3. First, the connection switching control unit 102 controls the switching unit 106 so as to connect the secondary battery B111 and the device operation unit 101. Thus, power is supplied from the secondary battery B111 to the device operating unit 101 (S31). Thereafter, the connection switching control unit 102 controls the switching unit 105 so as to connect the charging circuit unit 100 and the secondary battery A110. Thereby, the secondary battery A110 is charged (S32).

  The battery state monitoring unit 103 monitors the capacities of the secondary battery A110 and the secondary battery B111 (S33). When secondary battery A110 is fully charged and secondary battery B111 is medium capacity (“A full charge / B medium” in S33), connection switching control section 102 is connected to charging circuit sections 100 and 2. The switching unit 105 is controlled to disconnect the secondary battery A110 (S34). In addition, after step S34, it is equivalent to the initial state of case 4.

  When secondary battery A110 is fully charged and secondary battery B111 has a lower capacity ("A full charge / B lower" in S33), connection switching control section 102 is connected to charging circuit sections 100 and 2. The switching unit 105 is controlled to disconnect the secondary battery A110 (S35). In addition, after step S35, it is equivalent to the initial state of case 7.

  If the capacities of the secondary battery A110 and the secondary battery B111 do not correspond to “A full charge / B middle” or “A full charge / B lower” (“other” in S33), step S33. repeat.

(Case 4)
Case 4 is a case where power is being supplied from the secondary battery B111 to the device operating unit 101, the secondary battery A110 is fully charged, and the secondary battery B111 is in the middle of capacity, and is the initial state. is there. In Case 4, the power supply from the secondary battery B111 is maintained without charging the secondary battery B111 until the secondary battery B111 reaches the lower capacity. When the secondary battery B111 becomes lower in capacity, the power supply is switched from the secondary battery A110, and then the secondary battery B111 is charged.

  The flow of processing in case 4 will be described with reference to FIG. FIG. 5 is a flowchart showing the flow of processing in case 4. First, the switching unit 106 is controlled so that the secondary battery B111 and the device operating unit 101 are connected, and power is being supplied from the secondary battery B111 to the device operating unit 101 (S41).

  Then, step S42 (power feeding step) is repeated until the battery state monitoring unit 103 detects that the remaining capacity of the secondary battery B111 is equal to or lower than the lower limit of capacity (NO in S42).

  On the other hand, when the battery state monitoring unit 103 detects that the remaining capacity of the secondary battery B111 is equal to or lower than the lower limit of capacity (YES in S42), the connection switching control unit 102 includes the secondary battery A110, the device operation unit 101, and the like. The switching unit 106 is controlled to connect the two. Thus, power is supplied from the secondary battery A110 to the device operating unit 101 (S43 (connection switching step)).

  Subsequently, the connection switching control unit 102 controls the switching unit 105 to connect the charging circuit unit 100 and the secondary battery B111. Thereby, the secondary battery B111 is charged (S44 (charging step)). In addition, after step S44, it is equivalent to the initial state of case 7.

(Case 5)
Case 5 is an initial state where power is being supplied from either one of the secondary batteries to the device operating unit 101, the secondary battery A110 is in the middle of capacity, and the secondary battery B111 is in the middle of capacity. This is the case. In Case 5, the power supply from the secondary battery is maintained without charging the secondary battery until the secondary battery being fed reaches the lower capacity. And when the said secondary battery becomes a capacity | capacitance low battery, it switches to the electric power feeding from the other secondary battery, and the secondary battery of the capacity | capacitance low battery is charged after that.

  The flow of processing in case 5 will be described with reference to FIG. FIG. 6 is a flowchart showing the flow of processing in case 5. FIG. 6A is a flowchart showing a flow of processing when an initial state is set when power is being supplied from the secondary battery B111 to the device operating unit 101. First, the switching unit 106 is controlled so that the secondary battery B111 and the device operating unit 101 are connected, and power is being supplied from the secondary battery B111 to the device operating unit 101 (S51).

  Step S52 (power feeding step) is repeated until the battery state monitoring unit 103 detects that the remaining capacity of the secondary battery B111 is equal to or lower than the lower limit of capacity (NO in S52).

  On the other hand, when the battery state monitoring unit 103 detects that the remaining capacity of the secondary battery B111 is equal to or lower than the lower limit of capacity (YES in S52), the connection switching control unit 102 includes the secondary battery A110, the device operation unit 101, and the like. The switching unit 106 is controlled to connect the two. Thus, power is supplied from the secondary battery A110 to the device operating unit 101 (S53 (connection switching step)).

  Subsequently, the connection switching control unit 102 controls the switching unit 105 to connect the charging circuit unit 100 and the secondary battery B111. Thereby, the secondary battery B111 is charged (S54 (charging step)).

  The battery state monitoring unit 103 monitors the capacities of the secondary battery A110 and the secondary battery B111 (S55). When secondary battery A110 is in the middle of capacity and secondary battery B111 is fully charged (“A medium / B full charge” in S55), connection switching control unit 102 is connected to charging circuit units 100 and 2. The switching unit 105 is controlled to disconnect the secondary battery B111 (S56). In addition, after step S56, it is equivalent to the initial state of case 2.

  When the secondary battery A110 has a lower capacity and the secondary battery B111 is fully charged (“A lower / B full charge” in S55), the connection switching control unit 102 is connected to the charging circuit units 100 and 2. The switching unit 105 is controlled to disconnect the secondary battery B111 (S57). In addition, after step S57, it is equivalent to the initial state of case 3.

  If the capacities of secondary battery A110 and secondary battery B111 do not correspond to either “A middle / B full charge” or “A lower / B full charge” (“Other” in S55), step S55 (charging step) is repeated.

  FIG. 6B is a flowchart showing the flow of processing when an initial state is set when power is being supplied from the secondary battery A110 to the device operating unit 101. Steps S61 to S67 shown in FIG. 6B are the same as steps S51 to S57 shown in FIG. 6A, respectively, except that the secondary battery A110 and the secondary battery B111 are replaced. The description is omitted here.

(Case 6)
Case 6 is a case in which the secondary battery A110 has a lower capacity and the secondary battery B111 has a middle capacity. In Case 6, power is being supplied from the secondary battery B111 to the device operating unit 101. Power is supplied from the secondary battery B111 and the secondary battery A110 is charged until full charge is reached. Since the flow of processing in case 6 is the same as that shown in the flowchart of FIG. 4, the description thereof is omitted here.

(Case 7)
Case 7 is a case in which the secondary battery A110 is fully charged and the secondary battery B111 has a lower capacity than the initial state. In case 7, power is supplied from the secondary battery A110, and the secondary battery B111 is charged until the battery reaches full charge. Note that power is not supplied from the secondary battery B111 until full charge is reached.

  The flow of processing in case 7 will be described with reference to FIG. FIG. 7 is a flowchart showing the flow of processing in case 7. First, the connection switching control unit 102 controls the switching unit 106 to connect the secondary battery A110 and the device operation unit 101, and power is supplied from the secondary battery A110 to the device operation unit 101 (S71). Further, the connection switching control unit 102 controls the switching unit 105 so as to connect the charging circuit unit 100 and the secondary battery B111. Thereby, the secondary battery B111 is charged (S72).

  The battery state monitoring unit 103 monitors the capacities of the secondary battery A110 and the secondary battery B111 (S73). When secondary battery A110 is in the middle of capacity and secondary battery B111 is fully charged ("A medium / B full charge" in S73), connection switching control section 102 is connected to charging circuit sections 100 and 2. The switching unit 105 is controlled to disconnect the secondary battery B111 (S74). In addition, after step S74, it is equivalent to the initial state of case 2.

  Further, when the secondary battery A110 has a lower capacity and the secondary battery B111 is fully charged ("A lower / B full charge" in S73), the connection switching control unit 102 includes the charging circuit units 100 and 2 The switching unit 105 is controlled to disconnect the secondary battery B111 (S75). In addition, after step S75, it is equivalent to the initial state of case 3.

  If the capacities of secondary battery A110 and secondary battery B111 do not correspond to either “A middle / B full charge” or “A lower / B full charge” (“Other” in S73), step Repeat S73.

(Case 8)
Case 8 is a case where the secondary battery A110 is in the middle of capacity and the secondary battery B111 is in the lower capacity. In Case 8, power is being supplied from the secondary battery A110 to the device operating unit 101. Power is supplied from the secondary battery A110, and the secondary battery B111 is charged until full charge is reached. Since the flow of processing in case 8 is the same as that shown in the flowchart of FIG. 7, the description thereof is omitted here.

(Case 9)
Case 9 is a case in which all secondary batteries are in the initial state when the capacity is lower. In case 9, the connection switching control unit 102 controls the switching unit 105 so as to charge any secondary battery. If the storage unit 107 is not provided, any secondary battery may be selected. On the other hand, when the storage unit 107 is provided, the secondary battery stored in the storage unit 107 is referred to, and the secondary battery with the smallest number of charge / discharge is charged. When the charging is completed, power supply is started from the secondary battery that has been charged, and the other secondary batteries are charged.

  The flow of processing in case 9 will be described with reference to FIG. FIG. 8 is a flowchart showing the flow of processing in case 9. Here, a case where the storage unit 107 is provided will be described.

  First, the connection switching control unit 102 refers to the charge / discharge counts of the secondary battery A110 and the secondary battery B111 stored in the storage unit 107 (S81).

  When the secondary battery A110 has a smaller number of charge / discharge cycles ("A is minimum" in S81), the connection switching control unit 102 switches the switching unit 105 to connect the charging circuit unit 100 and the secondary battery A110. To charge the secondary battery A110 (S82). Then, step S83 is repeated until the battery state monitoring unit 103 detects that the secondary battery A110 has reached full charge (NO in S83). When battery state monitoring unit 103 detects that secondary battery A110 has reached full charge (YES in S83), connection switching control unit 102 connects secondary battery A110 and device operating unit 101 to each other. The switching unit 106 is controlled. Thereby, electric power is supplied from the secondary battery A110 to the device operating unit 101 (S84).

  Thereafter, the connection switching control unit 102 controls the switching unit 105 to connect the charging circuit unit 100 and the secondary battery B111. Thereby, the secondary battery B111 is charged (S85). In addition, after step S84, it is equivalent to the initial state of case 7.

  On the other hand, when secondary battery B111 has a smaller number of charge / discharge cycles ("B is minimum" in S81), connection switching control unit 102 switches switching unit 105 to connect charging circuit unit 100 and secondary battery B111. To control. Thereby, the secondary battery B111 is charged (S86). Then, step S87 is repeated until the battery state monitoring unit 103 detects that the secondary battery B111 has reached full charge (NO in S87). When battery state monitoring unit 103 detects that secondary battery B111 has reached full charge (YES in S87), connection switching control unit 102 connects secondary battery B111 and device operating unit 101 to each other. The switching unit 106 is controlled. Thus, power is supplied from the secondary battery B111 to the device operating unit 101 (S88).

  Thereafter, the connection switching control unit 102 controls the switching unit 105 to connect the charging circuit unit 100 and the secondary battery A110. Thereby, the secondary battery A110 is charged (S89). In addition, after step S89, it is equivalent to the initial state of case 3.

(Supplementary information)
In the present embodiment, (1) the case where both secondary batteries have lower capacity and the initial state is set to start charging one secondary battery (that is, case 9), or (2) one secondary battery When the other secondary battery reaches a lower capacity while charging the battery (that is, “other” in step S33 and “other” in step S73), the secondary battery being charged is fully charged. Then, power supply to the device operating unit 101 is started.

  The reason for adopting this processing flow is to maximize the effect of extending the battery life. However, when this processing flow is adopted, a period in which the electronic device 1 cannot be driven until the secondary battery is fully charged occurs, which imposes a restriction that the convenience of the user is impaired.

  In order to solve this problem, exceptionally, if power is also supplied from the secondary battery being charged, it is possible to avoid the problem that a period during which the electronic device 1 cannot be driven occurs. It is preferable that the user can arbitrarily instruct whether or not to execute this exception processing. This makes it possible to select whether to give priority to improving battery life or to give priority to improving convenience according to a user instruction.

(Example of processing flow with Case 2 in the initial state)
Next, an example of the flow of processing for setting the case 2 to the initial state will be described with reference to FIG. FIG. 9 is a flowchart illustrating an example of a processing flow in the power supply apparatus 10 in which the case 2 is in an initial state. Here, a case where the storage unit 107 is provided will be described.

  First, the power supply apparatus 10 is connected to the charger via the charger I / F 104, and the device operating unit 101 operates by supplying power to the secondary battery A110 (S100). Note that the secondary battery A110 has a middle capacity, and is disconnected from the charging circuit unit 100 at this point.

  Next, while the remaining capacity of the secondary battery A110 is larger than the lower limit of capacity, the remaining capacity of the secondary battery A110 is monitored by the battery state monitoring unit 103 (NO in S101).

  If the battery state monitoring unit 103 detects that the battery capacity of the secondary battery A110 is lower than the capacity (YES in S101), the connection switching control unit 102 controls the switching unit 106 to start from the secondary battery B111. Switching to power supply to the device operating unit 101 is performed (S102). It should be noted that when switching, it is necessary to take measures such as instantaneous power interruption at the time of switching by using a large-capacitance capacitor or the like so that the device operation unit 101 does not turn off, but this is a well-known technical means. In this embodiment, no particular mention is made because it can be easily realized.

  Next, the connection switching control unit 102 controls the switching unit 105 to connect the secondary battery A110 to the charging circuit unit 100 and start charging the secondary battery A110 (S103). At this time, the device operating unit 101 is operated only by power supply from the secondary battery B111, and the secondary battery A110 is connected only to the charging circuit unit 100. The charging current is stabilized and charging in an ideal state can be realized.

  Next, the remaining capacity of secondary battery A110 calculated by battery state monitoring unit 103 is monitored until secondary battery A110 is fully charged (NO in S104). If the battery state monitoring unit 103 detects that the battery capacity of the secondary battery A110 has reached full charge (YES in S104), the connection switching control unit 102 controls the switching unit 105 to control the secondary battery A110. Is disconnected from the charging circuit unit 100 to complete the charging of the secondary battery A110 (S105), and then the process ends.

  Although not shown in this flowchart, the number of times of charging / discharging the secondary battery A110 and the secondary battery B111 is recorded in the storage unit 107. For example, when the remaining capacity of both secondary batteries is substantially the same, the secondary battery with the smaller number of charge / discharge cycles is used to supply power to the device operating unit 101. Thereby, it becomes possible to perform more preferable control, such as being able to average the number of times of charge and discharge of both the secondary batteries.

(Connection status of switching unit)
Next, the state and transition of the connection destination of the switching unit 105 and the switching unit 106 in each step of the flowchart shown in FIG. 9 will be described with reference to FIG.

  As shown in FIG. 10, in the initial state, step S100, and step S101, the charging circuit unit 100 is not connected to either the secondary battery A110 or the secondary battery B111. ”)”. On the other hand, the device operating unit 101 is connected to the secondary battery A110.

  Next, in step S102, the power supply source to the device operating unit 101 is switched, and the device operating unit 101 is connected to the secondary battery B111. Note that the charging circuit unit 100 is still not connected to either the secondary battery A110 or the secondary battery B111.

  Next, in step S103, the charging circuit unit 100 is connected to the secondary battery A110. The device operating unit 101 remains connected to the secondary battery B111.

  Next, in step S104, the connection state does not change. That is, the charging circuit unit 100 is connected to the secondary battery A110, and the device operating unit 101 remains connected to the secondary battery B111.

  Next, in step S <b> 105, the secondary battery A <b> 110 that has reached full charge is disconnected from the charging circuit unit 100. The device operating unit 101 remains connected to the secondary battery B111. Thereafter, the process ends.

(Arrangement of feature points)
As described above, the power supply apparatus 10 mainly has the following characteristics (1) and (2).

  (1) For the purpose of charging after using a secondary battery as much as possible, power is supplied from the secondary battery until the battery capacity of the secondary battery being supplied reaches a lower capacity limit that can be used in actual use. When the capacity lower limit is reached, the power supply is switched from another secondary battery. Further, unless the secondary battery is used until the capacity becomes lower, even if a charger is connected, the secondary battery is not charged. The secondary battery as the power supply source after switching is at least a secondary battery that is not being charged. Furthermore, when the number of times of charging / discharging has been recorded, the secondary battery having the smallest number of charging / discharging times. It is desirable that

  (2) The secondary battery discharged to the lower capacity is connected only to the charging circuit unit 100. The connection to the charging circuit unit 100 and the connection to the device operation unit 101 are exclusive, and the secondary battery being charged is not connected to the load.

(Function and effect)
As described above, the power supply device 10 uses the secondary battery until the capacity becomes lower, and then charges the secondary battery. Therefore, the number of times of charging / discharging the secondary battery can be reduced as compared with the conventional case. Therefore, since the frequency of charging / discharging is reduced, the period until the predetermined number of charging / discharging cycles is reached can be extended.

  Furthermore, when switching the secondary battery as the power supply source, if the secondary battery with the smallest number of charge / discharge cycles is used with priority, the number of charge / discharge cycles is averaged among the secondary batteries. It is realized that the period until the number of charge / discharge cycles of the secondary battery is reached is lengthened.

  Further, the secondary battery is connected only to the charging circuit unit 100 during charging and is not connected to the device operating unit 101. Therefore, since the charging current is stabilized, it is possible to expect an effect that the charge / discharge cycle life (possible number of times) can be extended. Since the product life as a secondary battery is the limit number of charge / discharge cycles, the product life can be extended as a result.

[Embodiment 2]
In the first embodiment, an embodiment in which a secondary battery such as a lithium ion battery that can be recharged is used has been described. However, the present invention is not limited to those that can be charged by adding different types of secondary batteries. Thus, in the present embodiment, an embodiment will be described in which a secondary battery such as a nickel cadmium battery that cannot be recharged due to the memory effect is adopted.

  Another embodiment of the present invention will be described below with reference to FIGS.

(Configuration of power supply)
The configuration of the power supply device 20 according to this embodiment will be described with reference to FIG. FIG. 11 is a block diagram illustrating a configuration of the power supply device 20. As shown in the figure, the power supply device 20 includes a secondary battery A210, a secondary battery B211, a charging circuit unit (charging unit) 200, a connection switching control unit (connection switching unit) 202, a battery state monitoring unit 203, and a charger. An I / F 204, a switching unit 205, a switching unit 206, a switching unit 207, a discharge unit (discharge means) 208, and a storage unit 209 are provided. However, the storage unit 209 is not necessarily provided.

  In the figure, the power supply device 20 is mounted on the electronic device 2 including the device operating unit 201. The device operation unit 201 is a main system unit that executes various functions of the electronic device 2, and is a load when viewed from the power supply device 20.

  Since the charging circuit unit 200 and the charger I / F 204 have the same functions as the charging circuit unit 100 and the charger I / F 104 of the first embodiment, respectively, description thereof is omitted.

  Secondary battery A210 and secondary battery B211 are batteries such as a nickel cadmium battery that cannot be recharged due to the memory effect.

  Next, the connection switching control unit 202 controls the switching unit 205, the switching unit 206, and the switching unit 207. The switching unit 205, the switching unit 206, and the switching unit 207 are controlled based on the remaining capacity of the secondary battery detected by the battery state monitoring unit 203 and the number of charge / discharge times of the secondary battery stored in the storage unit 209. A configuration is preferred. Details of the control contents will be described later.

  Further, when the storage unit 209 is provided, the connection switching control unit 202, when the secondary battery and the charging circuit unit 100 are connected, is stored in the storage unit 209 of the connected secondary battery. Update the charging / discharging count by one. When the secondary battery and the device operation unit 201 are connected, the charge / discharge count of the connected secondary battery stored in the storage unit 209 may be updated by one.

  Next, the battery state monitoring unit 203 constantly monitors the secondary battery A210 and the secondary battery B211 and uses the battery voltage, the integrated value of the charge / discharge current, and the like to keep the secondary battery A210 and the secondary battery B211 remaining. Calculate capacity. The battery state monitoring unit 203 is at least (1) fully charged for each of the secondary battery A210 and the secondary battery B211. (2) The remaining capacity is lower than the capacity (lower than the lower limit of capacity). (3) It is detected that the remaining capacity is medium, and (4) that there is no remaining capacity (that is, complete discharge).

  Next, the switching unit 205 is controlled by the connection switching control unit 202 to perform charging path selection and path switching. More specifically, (1) the charging circuit unit 200 and the secondary battery A210 are connected, (2) the charging circuit unit 200 and the secondary battery B211 are connected, and (3) the charging circuit unit 200 is connected to the secondary battery A210. Or the secondary battery B211 (in other words, the connection between the charging circuit unit 200 and the secondary battery is disconnected).

  Similarly, the switching unit 206 is controlled by the connection switching control unit 202 and performs power supply route selection and route disconnection switching. More specifically, (1) the secondary battery A210 and the device operating unit 201 are connected, (2) the secondary battery B211 and the device operating unit 201 are connected, and (3) the device operating unit 201 is connected to the secondary battery A210. Or the secondary battery B211 (in other words, the connection between the device operating unit 201 and the secondary battery is disconnected).

  Similarly, the switching unit 207 is controlled by the connection switching control unit 202 and performs discharge path selection and path disconnection switching. More specifically, (1) the discharge unit 208 and the secondary battery A210 are connected, (2) the discharge unit 208 and the secondary battery B211 are connected, and (3) the discharge unit 208 is also connected to the secondary battery A210. Switch to either one of the secondary batteries B211 (in other words, disconnect the connection between the discharge unit 208 and the secondary battery).

  Next, the discharge unit 208 includes a discharge resistor and the like, and completely discharges the connected secondary battery.

  Finally, the storage unit 209 stores the number of times of charge / discharge of each of the secondary battery A210 and the secondary battery B211 and is configured by a storage device such as an EEPROM.

(Details of connection switching control)
When the charger is connected, the connection switching control unit 202 controls the switching unit 205, the switching unit 206, and the switching unit 207 so as to perform power feeding and charging as in cases 1 ′ to 9 ′ described below. Cases 1 ′ to 9 ′ correspond to cases 1 to 9 of the first embodiment, respectively.

(Case 1 ')
Case 1 ′ is a case in which the initial state is when all the secondary batteries are fully charged. In case 1 ′, the connection switching control unit 202 controls the switching unit 206 so as to start power feeding from any of the secondary batteries. When the storage unit 209 is not provided, any secondary battery may be selected. On the other hand, when the storage unit 209 is provided, the charging / discharging frequency of each secondary battery stored in the storage unit 209 is referred to, and power supply is started from the secondary battery having the smallest charging / discharging frequency. In either case, neither secondary battery is charged.

  The flow of processing in case 1 'is as shown in steps S111 to S113 shown in FIG. 12, but is the same as steps S11 to S13 shown in FIG.

(Case 2 ')
Case 2 ′ is a case where power is being supplied from the secondary battery A210 to the device operating unit 201, the secondary battery A210 is in the middle of capacity, and the secondary battery B211 is fully charged. It is. In case 2 ′, the secondary battery A210 is not charged until the secondary battery A210 becomes lower in capacity, and the power supply from the secondary battery A210 is maintained. When the secondary battery A210 becomes lower in capacity, the power supply is switched to the power supply from the secondary battery B211. After that, the secondary battery A210 is completely discharged and then the secondary battery A210 is charged.

  The process flow in case 2 ′ is as shown in steps S <b> 121 to S <b> 124 shown in FIG. 13, but is the same as steps S <b> 21 to S <b> 24 shown in FIG.

  After step S123, the connection switching control unit 202 controls the switching unit 207 to connect the secondary battery A210 and the discharge unit 208. Thereby, the secondary battery A210 is discharged (S125). When the battery state monitoring unit 203 detects that the remaining capacity of the secondary battery A210 is lost (YES in S126), the secondary battery A210 and the discharge unit 208 are disconnected (S127). Thereafter, the secondary battery A210 is charged (S124).

(Case 3 ')
Case 3 ′ is a case in which the secondary battery A210 has a lower capacity and the secondary battery B211 is fully charged. In case 3 ′, power is supplied from the secondary battery B211 and charging is performed until the secondary battery A210 reaches full charge after the secondary battery A210 is completely discharged.

  The flow of processing in case 3 'will be described with reference to FIG. Steps S131 to S135 shown in FIG. 14 are the same as steps S31 to S35 shown in FIG. Steps S136 to S138 will be described.

  After step S131, the connection switching control unit 202 controls the switching unit 207 to connect the secondary battery A210 and the discharge unit 208. Thereby, the secondary battery A210 is discharged (S136). When the battery state monitoring unit 203 detects that the remaining capacity of the secondary battery A210 is lost (YES in S137), the secondary battery A210 and the discharge unit 208 are disconnected (S138). Thereafter, the secondary battery A210 is charged (S132).

(Case 4 ')
Case 4 ′ is a case where power is being supplied from the secondary battery B211 to the device operating unit 201, the secondary battery A210 is fully charged, and the secondary battery B211 is in the middle of capacity. It is. In case 4 ′, the secondary battery B211 is not charged until the secondary battery B211 reaches the lower capacity, and the power supply from the secondary battery B211 is maintained. When the secondary battery B211 becomes lower in capacity, the power supply is switched from the secondary battery A210, and after that, the secondary battery B211 is completely discharged and then the secondary battery B211 is charged.

  The flow of processing in case 4 'is as shown in steps S141 to S144 shown in FIG. 15, but is the same as steps S41 to S44 shown in FIG.

  After step S143, the connection switching control unit 202 controls the switching unit 207 to connect the secondary battery B211 and the discharging unit 208. Thereby, the secondary battery B211 is discharged (S145). When the battery state monitoring unit 203 detects that the remaining capacity of the secondary battery B211 has disappeared (YES in S146), the secondary battery B211 and the discharge unit 208 are disconnected (S147). Thereafter, the secondary battery B211 is charged (S144).

(Case 5 ')
Case 5 ′ is an initial case where power is being supplied from either one of the secondary batteries to the device operating unit 201, the secondary battery A210 is in the middle of capacity, and the secondary battery B211 is in the middle of capacity. It is a case to be a state. In case 5 ′, power supply from the secondary battery is maintained without charging the secondary battery until the secondary battery being fed reaches the lower capacity. And when the said secondary battery becomes a capacity | capacitance low capacity | capacitance, it switches to the electric power feeding from the other secondary battery, and after that, the secondary battery in the capacity | capacitance low capacity | capacitance is discharged completely, and is charged.

  The flow of processing in case 5 'will be described with reference to FIG. FIG. 16A is a flowchart showing the flow of processing when the case where power is being supplied from the secondary battery B211 to the device operating unit 201 is set to the initial state. Steps S151 to S157 shown in FIG. 16A are the same as steps S51 to S57 shown in FIG. Steps S158 to S160 will be described.

  After step S153, the connection switching control unit 202 controls the switching unit 207 to connect the secondary battery B211 and the discharging unit 208. Thereby, the secondary battery B211 is discharged (S158). When the battery state monitoring unit 203 detects that the remaining capacity of the secondary battery B211 has run out (YES in S159), the secondary battery B211 and the discharge unit 208 are disconnected (S160). Thereafter, the secondary battery B211 is charged (S154).

  Next, FIG. 16B is a flowchart showing the flow of processing when the case where power is being supplied from the secondary battery A210 to the device operating unit 201 is set to an initial state. Steps S161 to S167 shown in FIG. 16B are the same as steps S61 to S67 shown in FIG. Steps S168 to S170 will be described.

  After step S163, the connection switching control unit 202 controls the switching unit 207 to connect the secondary battery A210 and the discharge unit 208. Thereby, the secondary battery A210 is discharged (S168). When the battery state monitoring unit 203 detects that the remaining capacity of the secondary battery A210 is exhausted (YES in S169), the secondary battery A210 and the discharge unit 208 are disconnected (S170). Thereafter, the secondary battery A210 is charged (S164).

(Case 6 ')
Case 6 ′ is a case in which the secondary battery A210 has a lower capacity and the secondary battery B211 has a middle capacity. In Case 6 ′, power is being supplied from the secondary battery B111 to the device operating unit 101. Power is supplied from the secondary battery B111 and the secondary battery A210 is fully charged after the secondary battery A210 is completely discharged. Charge until it reaches. Since the flow of processing in case 6 ′ is the same as the flowchart shown in FIG. 14, the description thereof is omitted here.

(Case 7 ')
Case 7 ′ is a case in which the secondary battery A210 is fully charged and the secondary battery B211 has a lower capacity, which is the initial state. In case 7 ′, power is supplied from the secondary battery A110, and after the secondary battery B111 is completely discharged, the secondary battery B111 is charged until the battery reaches full charge.

  The flow of processing in case 7 'will be described with reference to FIG. Steps S171 to S175 shown in FIG. 17 are the same as steps S71 to S75 shown in FIG. Steps S176 to S178 will be described.

  After step S171, the connection switching control unit 202 controls the switching unit 207 to connect the secondary battery B211 and the discharging unit 208. Thereby, the secondary battery B211 is discharged (S176). If the battery state monitoring unit 203 detects that the remaining capacity of the secondary battery B211 has run out (YES in S177), the secondary battery B211 and the discharge unit 208 are disconnected (S178). Thereafter, the secondary battery B211 is charged (S172).

(Case 8 ')
Case 8 ′ is a case in which the secondary battery A210 is in the middle of capacity and the secondary battery B211 is in the lower capacity. In Case 8 ′, power is being supplied from the secondary battery A210 to the device operating unit 201. Power is supplied from the secondary battery A110, and the secondary battery B111 is completely discharged until reaching full charge. The secondary battery B111 is charged. Since the flow of processing in case 8 ′ is the same as the flowchart shown in FIG. 17, the description thereof is omitted here.

(Case 9 ')
Case 9 ′ is a case in which all secondary batteries A210 are in the initial state when the capacity is lower. In case 9 ′, the connection switching control unit 202 controls the switching unit 105 so as to charge any secondary battery. When the storage unit 209 is not provided, any secondary battery may be selected. On the other hand, when the storage unit 209 is provided, the secondary battery A210 and the secondary battery B211 stored in the storage unit 209 are referred to, and the secondary battery with the smallest number of charge / discharge is discharged. To charge the secondary battery. When the charging is completed, power supply is started from the secondary battery that has been charged, and the secondary battery is charged after discharging other secondary batteries.

  The flow of processing in case 9 'will be described with reference to FIG. Here, a case where the storage unit 209 is provided will be described. Steps S181 to S189 shown in FIG. 18 are the same as steps S81 to S89 shown in FIG. Steps S1901 to S1912 will be described.

  When “A is minimum” in step S181 and after step S188, the connection switching control unit 202 controls the switching unit 207 to connect the secondary battery A210 and the discharge unit 208. Thereby, the secondary battery A210 is discharged (S1901, S1910). When the battery state monitoring unit 203 detects that the remaining capacity of the secondary battery A210 has run out (YES in S1902 and YES in S1911), the secondary battery A210 and the discharge unit 208 are disconnected (S1903, S1912). .

  When “B is minimum” in step S181 and after step S184, the connection switching control unit 202 controls the switching unit 207 to connect the secondary battery B211 and the discharge unit 208. Thereby, the secondary battery B211 is discharged (S1907, S1904). When the battery state monitoring unit 203 detects that the remaining capacity of the secondary battery B211 has run out (YES in S1908, YES in S1905), the secondary battery B211 and the discharge unit 208 are disconnected (S1909, 1906). .

(Example of processing flow with case 2 'as the initial state)
Next, an example of the flow of processing for setting the case 2 ′ to the initial state will be described with reference to FIG. FIG. 19 is a flowchart illustrating an example of a processing flow of the power supply device 20 in which the case 2 ′ is in an initial state. Here, a case where the storage unit 209 is provided will be described. Steps S200 to S206 shown in FIG. 19 are the same as steps S100 to S105 shown in FIG. 9 except for step S203.

  In step S <b> 203, the connection switching control unit 202 controls the switching unit 207 to connect the secondary battery A 210 and the discharging unit 208. Thereby, the secondary battery A210 is discharged. Then, when the battery state monitoring unit 203 detects that the remaining capacity of the secondary battery A210 is lost, the secondary battery B211 and the discharge unit 208 are disconnected.

  Although not shown in this flowchart, the charge / discharge counts of the secondary battery A210 and the secondary battery B211 are recorded in the storage unit 209. For example, when the remaining capacity of both secondary batteries is substantially the same, the secondary battery with the smaller number of charge / discharge cycles is used to supply power to the device operating unit 201. Thereby, like Embodiment 1, it becomes possible to perform more preferable control, such as being able to average the charging / discharging frequency of both secondary batteries.

(Connection status of switching unit)
Next, with reference to FIG. 20, the state and transition of the connection destination of the switching unit 205, the switching unit 206, and the switching unit 207 in each step of the flowchart shown in FIG.

  As shown in FIG. 20, in the initial state, step S200, and step S201, the charging circuit unit 200 is not connected to either the secondary battery A210 or the secondary battery B211. Notation). On the other hand, the device operating unit 201 is connected to the secondary battery A210. In addition, since neither the secondary battery A210 nor the secondary battery B211 is discharged, it is not connected to the discharge unit 208.

  Next, in step S202, the power supply connection source to the device operating unit 201 is switched, and the device operating unit 201 is connected to the secondary battery B211. Note that the charging circuit unit 200 is still not connected to either the secondary battery A210 or the secondary battery B211. Further, the secondary battery A210 and the secondary battery B211 are not yet connected to the discharge unit 208.

  Next, in step S203, the secondary battery A210 is discharged and connected to the secondary battery A210 and the discharge unit 208. Then, when the discharge is completed, the secondary battery A210 and the discharge unit 208 are disconnected. Note that the device operating unit 201 remains connected to the secondary battery B211. Further, the charging circuit unit 200 is still not connected to either the secondary battery A210 or the secondary battery B211.

  Next, in step S204, the charging circuit unit 200 is connected to the secondary battery A210. Note that the device operating unit 201 remains connected to the secondary battery B211. Neither the secondary battery A210 nor the secondary battery B211 is connected to the discharge unit 208.

  Next, in step S205, the connection state does not change. That is, the charging circuit unit 200 is connected to the secondary battery A210, the device operation unit 201 remains connected to the secondary battery B211, and both the secondary battery A210 and the secondary battery B211 are connected to the discharge unit 208. Not connected.

  Next, in step S <b> 206, the secondary battery A <b> 210 that has reached full charge is disconnected from the charging circuit unit 200. Note that the device operation unit 201 remains connected to the secondary battery B211 and neither the secondary battery A210 nor the secondary battery B211 is connected to the discharge unit 208. Thereafter, the process ends.

(Arrangement of feature points)
As described above, in addition to the characteristics of the power supply device 10 of the first embodiment, the power supply device 20 further connects the secondary battery to the discharge unit 208 and discharges the secondary battery when charging the secondary battery. The secondary battery is charged.

(Function and effect)
According to the configuration of the present embodiment, since the battery is not charged in a state where the capacity remains, a secondary battery that cannot be recharged due to the memory effect such as a nickel cadmium battery is provided. Even if it exists, there exists an effect that generation | occurrence | production of a memory effect can be suppressed.

[Embodiment 3]
In the present embodiment, a power supply device including three secondary batteries will be described.

  Still another embodiment of the present invention will be described below with reference to FIGS.

(Configuration of power supply)
The configuration of the power supply device 30 according to the present embodiment will be described with reference to FIG. FIG. 21 is a block diagram illustrating an outline of the configuration of the power supply device 30. As shown in the figure, the power supply 30 includes a secondary battery A310, a secondary battery B311, a secondary battery C312, a charging circuit unit (charging unit) 300, a connection switching control unit (connection switching unit) 302, and a battery state monitor. Unit 303, charger I / F 304, switching unit 305, switching unit 306, and storage unit 307. However, the storage unit 307 is not necessarily provided.

  In the figure, the power supply device 30 is mounted on the electronic device 3 including the device operating unit 301. The device operation unit 301 is a main system unit that executes various functions of the electronic device 2, and is a load when viewed from the power supply device 30.

  The secondary battery A310, the secondary battery B311, the charging circuit unit 300, and the charger I / F 304 are the secondary battery A110, the secondary battery B111, the charging circuit unit 100, and the charger I / F 104 of the first embodiment, respectively. The description of the function is omitted.

  The secondary battery C312 is a battery that can be recharged, such as a lithium ion battery.

  Next, the connection switching control unit 302 controls the switching unit 305 and the switching unit 306. A configuration in which the switching unit 305 and the switching unit 306 are controlled based on the remaining capacity of the secondary battery calculated by the battery state monitoring unit 303 and the number of times of charging / discharging of the secondary battery stored in the storage unit 307 is preferable. Details of the control contents will be described later.

  In addition, when the storage unit 307 is provided, the connection switching control unit 302 stores the connected secondary battery stored in the storage unit 307 when the secondary battery and the charging circuit unit 100 are connected. Update the charging / discharging count by one. When the secondary battery and the device operation unit 301 are connected, the charge / discharge count of the connected secondary battery stored in the storage unit 307 may be increased by one and updated.

  Next, the battery state monitoring unit 303 constantly monitors the secondary battery A310, the secondary battery B311, and the secondary battery C312. The secondary battery A310, the integrated value of the battery voltage and charge / discharge current, and the like are used. The remaining capacities of the secondary battery B311 and the secondary battery C312 are calculated. The battery state monitoring unit 303 at least (1) is fully charged and (2) the remaining capacity is lower than the capacity of each of the secondary battery A110, the secondary battery B111, and the secondary battery C312. (3) It is detected that the remaining capacity is medium capacity.

  Next, the switching unit 305 is controlled by the connection switching control unit 302 to perform charging path selection and path switching. More specifically, (1) the charging circuit unit 300 and the secondary battery A310 are connected, (2) the charging circuit unit 300 and the secondary battery B311 are connected, (3) the charging circuit unit and the secondary battery C312 (4) The charging circuit unit 300 is switched to either the secondary battery A310, the secondary battery B311 or the secondary battery C312.

  Similarly, the switching unit 306 is controlled by the connection switching control unit 302 and performs power supply route selection and route disconnection switching. More specifically, (1) the secondary battery A310 and the device operating unit 301 are connected, (2) the secondary battery B311 and the device operating unit 301 are connected, and (3) the secondary battery C312 and the device operating unit 301 are connected. (4) The device operating unit 301 is switched to either the secondary battery A310, the secondary battery B311 or the secondary battery C312.

  Finally, the storage unit 307 stores the number of times of charging / discharging each of the secondary battery A310, the secondary battery B311, and the secondary battery C312 and is configured by a storage device such as an EEPROM.

(Details of connection switching control)
The connection switching control unit 302 is different in that the number of secondary batteries is three, but performs the same control as the connection switching control unit 102 described in the first embodiment.

  In particular, the connection switching control unit 302 controls the switching unit 306 so as to maintain power feeding from the secondary battery that is being fed, and the switching unit 305 so as not to connect the secondary battery and the charging circuit unit 300. To control.

  When the battery state monitoring unit 303 detects that the secondary battery being fed has reached a lower capacity, the connection switching control unit 302 selects one of the secondary batteries excluding the secondary battery being fed. The switching unit 106 is controlled so as to start feeding from the secondary battery. When the storage unit 307 is not provided, any secondary battery may be selected. On the other hand, in the case where the storage unit 307 is provided, among the secondary batteries excluding the secondary battery that is being fed, charging / discharging that is not connected to the charging circuit unit 300 and is stored in the storage unit 307 The switching unit 306 is controlled to connect the secondary battery with the smallest number of times and the device operating unit 301. Thereafter, the switching unit 305 is controlled so as to connect the secondary battery that has reached the lower capacity and the charging circuit unit 300, and charging is continued until the battery is fully charged. Power is not supplied until the battery is fully charged.

(Example of processing flow)
Referring to FIG. 22, power is being supplied from secondary battery A310 to device operating unit 301, secondary battery A310 is in the middle of capacity, secondary battery B311 is fully charged, and secondary battery. An operation example of the connection switching control unit 302 in the case where C3 is fully charged will be described as an initial state. FIG. 22 is a flowchart illustrating an example of a process flow from the initial state in the power supply device 30. Here, a case where the storage unit 307 is provided will be described.

  First, the power supply device 30 is connected to the charger via the charger I / F 304, and the device operating unit 301 operates by supplying power to the secondary battery A310 (S300). Note that the secondary battery A310 has a remaining capacity in the middle of the capacity, and is disconnected from the charging circuit unit 300 at this time.

  Next, while the remaining capacity of secondary battery A310 is greater than the lower limit of capacity, the remaining capacity of secondary battery A310 calculated by battery state monitoring unit 303 is monitored (NO in S301).

  If the battery state monitoring unit 303 detects that the battery capacity of the secondary battery A310 is lower than the capacity (YES in S301), the connection switching control unit 302 selects the secondary battery excluding the secondary battery A310. The secondary battery that is not connected to the charging circuit unit 100 and has the smallest number of charge / discharge cycles stored in the storage unit 307 (that is, the smallest number of charge / discharge cycles among the secondary battery B311 and the secondary battery C312). Secondary battery). When the number of times of charging / discharging of the secondary battery B311 is minimum ("B is minimum" in S302), the switching unit 306 is controlled by the connection switching control unit 302 to switch the power supply from the secondary battery B311 to the device operating unit 301. (S303). When switching, it is necessary to take measures such as instantaneous power interruption at the time of switching using a large-capacitance capacitor or the like so that the device operating unit 301 does not turn off. This is a well-known technical means. In this embodiment, no particular mention is made because it can be easily realized.

  Next, the switching switching unit 305 is controlled by the connection switching control unit 302 to connect the secondary battery A310 to the charging circuit unit 300, and charging of the secondary battery A310 is started (S304). At this time, the device operating unit 301 is operated only by power supply from the secondary battery B 311, and the secondary battery A 310 is connected only to the charging circuit unit 300. The charging current is stabilized and charging in an ideal state can be realized.

  Next, the remaining capacity of secondary battery A310 calculated by battery state monitoring unit 303 is monitored until secondary battery A310 is fully charged (NO in S305). If the battery state monitoring unit 103 detects that the battery capacity of the secondary battery A310 has reached full charge (YES in S305), the connection switching control unit 302 controls the switching unit 305 to control the secondary battery A310. Is disconnected from the charging circuit unit 300 to complete the charging of the secondary battery A310, and then the process ends.

  On the other hand, when the number of times of charging / discharging of secondary battery C312 is minimum ("C is minimum" in S302), switching unit 306 is controlled by connection switching control unit 302, and power is supplied from secondary battery C312 to device operating unit 301. (S307). Steps S308 to S310 are the same as steps S304 to S306, and a description thereof will be omitted.

(Connection status of switching unit)
Next, with reference to FIG. 23, the state and transition of the connection destinations of the switching unit 305 and the switching unit 306 in each step of the flowchart illustrated in FIG. 23 will be described.

  As shown in FIG. 23, in the initial state, Steps S300 to S302, charging circuit unit 300 is not connected to any of secondary battery A310, secondary battery B311 and secondary battery C312. On the other hand, the device operation unit 301 is connected to the secondary battery A310.

  Next, in step S303, the power supply connection source to the device operation unit 301 is switched, and the device operation unit 301 is connected to the secondary battery B311. Note that the charging circuit unit 300 is still not connected to either the secondary battery A310 or the secondary battery B311.

  Next, in step S304, charging circuit unit 300 is connected to secondary battery A310. Note that the device operation unit 301 remains connected to the secondary battery B311.

  Next, in step S305, the connection state does not change. That is, the charging circuit unit 300 is connected to the secondary battery A310, and the device operating unit 301 remains connected to the secondary battery B311.

  Next, in step S <b> 306, the secondary battery A <b> 310 that has reached full charge is disconnected from the charging circuit unit 300. Note that the device operation unit 301 remains connected to the secondary battery B311. Thereafter, the process ends.

  Next, in step S307, the power supply connection source to the device operating unit 301 is switched, and the device operating unit 301 is connected to the secondary battery C312. Note that the charging circuit unit 300 is still not connected to either the secondary battery A310 or the secondary battery B311.

  Next, in step S308, the charging circuit unit 300 is connected to the secondary battery A310. The device operating unit 301 remains connected to the secondary battery C312.

  Next, in step S309, the connection state does not change. That is, the charging circuit unit 300 is connected to the secondary battery A310, and the device operating unit 301 remains connected to the secondary battery C312.

  Next, in step S <b> 310, the secondary battery A <b> 310 that has reached full charge is disconnected from the charging circuit unit 300. The device operating unit 301 remains connected to the secondary battery C312. Thereafter, the process ends.

(Arrangement of feature points)
As described above, the power supply device 30 has the following characteristics (1) and (2).

  (1) For the purpose of charging after using the secondary battery as much as possible, when the battery capacity of the secondary battery being fed reaches a lower capacity, the power from any of the remaining secondary batteries Switch to supply. At this time, it is desirable to switch to power supply from a secondary battery with the smallest number of charge / discharge cycles. In addition, even if a charger is connected, the secondary battery of medium capacity is not charged unless it is used until the battery capacity becomes lower.

  (2) The secondary battery discharged to the lower capacity is connected only to the charging circuit unit 300. The connection to the charging circuit unit 300 and the connection to the device operation unit 301 are exclusive, and the secondary battery being charged is not connected to the load.

(Function and effect)
The power supply device 30 has the same effects as the effects described in the first embodiment. That is, the number of times of charging / discharging the secondary battery can be reduced as compared with the conventional case, and the frequency of charging / discharging is reduced, so that the period until the predetermined number of charging / discharging cycles is reached can be extended.

  Further, as in the first embodiment, since the charging current is stabilized, an effect of extending the charge / discharge cycle life (possible number of times) can be expected, and as a result, the product life can be extended.

(Modification)
In addition to the configuration shown in the third embodiment, the discharge unit described in the second embodiment may be further provided, and when the secondary battery is charged, the secondary battery may be completely discharged and then charged. Thereby, even if it is a case provided with the secondary battery which cannot be recharged, such as a nickel cadmium battery, there exists the effect mentioned above.

[Additional Notes]
The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention.

  The present invention can be applied to a power supply device that includes a plurality of rechargeable secondary batteries and supplies power to a load from any of the secondary batteries.

1, 2, 3 Electronic device 10, 20, 30 Power supply device 100, 200, 300 Charging circuit unit (charging unit)
101, 201, 301 Device operation unit (load)
102, 202, 302 Connection switching control unit (connection switching means)
107, 209, 307 Storage unit 208 Discharge unit (discharge means)
A110, B111 secondary battery A210, B211 secondary battery A310, B311, C312 secondary battery

Claims (7)

A power supply device comprising a plurality of rechargeable secondary batteries and a charging unit for charging the secondary batteries, wherein the power supply device supplies power to a load from any of the plurality of secondary batteries,
Connection switching means for connecting and disconnecting any one of the plurality of secondary batteries and the charging unit, and connecting and disconnecting any one of the plurality of secondary batteries and the load ;
A storage unit that stores, for each secondary battery, the number of times that the secondary battery has been charged and discharged ;
The connection switching means is
The secondary battery connected to the load is connected only to the load until the capacity reaches a predetermined lower limit,
When the capacity of the secondary battery connected to the load reaches the lower limit,
Among the secondary batteries, except for the two batteries are disconnected and the charging unit, the charge and discharge count stored in the storage unit and the minimum of the secondary batteries, with thereby connecting the load ,
The secondary battery whose capacity has reached the lower limit is connected only to the charging part until the capacity reaches the highest level ,
When all of the plurality of secondary batteries have a capacity equal to or lower than the lower limit value and are not connected to the charging unit,
The connection switching means is
The secondary battery stored in the storage unit with the minimum number of times of charging / discharging is connected to the charging unit until the capacity reaches the highest level, and the load is not connected to any of the plurality of secondary batteries. ,
After that, when the capacity of the secondary battery connected to the charging unit reaches the highest level, the secondary battery is connected only to the load,
If there is a user's instruction, during charging, the secondary battery of the charge and discharge times are minimal, the power supply device according to claim Rukoto is also connected to the load. When the secondary battery and the charging unit are connected, the connection switching unit updates the number of charge / discharge cycles of the connected secondary battery stored in the storage unit by one. The power supply device according to claim 1 . When the secondary battery and the load are connected, the connection switching means updates the charge / discharge count of the connected secondary battery, which is stored in the storage unit, by one. The power supply device according to claim 1 . When the capacities of all the secondary batteries are highest,
The connection switching means connects the secondary battery having the smallest number of charge / discharge cycles stored in the storage unit and the load, and does not connect the charging unit to any of the plurality of secondary batteries. the power supply device according to any one of claims 1, wherein 3. A discharge means for discharging the connected secondary battery;
The connection switching means further causes connection and disconnection between any of the plurality of secondary batteries and the discharge means,
Said connection switching means, prior to connecting the secondary battery and the charging unit, the secondary battery for the connection, from claim 1, characterized in that to connect with said discharge means to the capacity disappears 4 The power supply device according to any one of the above. Electronic apparatus comprising a power supply device according to any one of claims 1 to 5, the load and which is powered from the power supply. A control method for a power supply apparatus comprising a plurality of rechargeable secondary batteries and a charging unit for charging the secondary batteries, wherein the power supply device supplies power to a load from any of the plurality of secondary batteries,
The power supply device includes a storage unit that stores, for each secondary battery, a charge / discharge count that is the number of times the secondary battery is charged and discharged.
A power feeding step of connecting the secondary battery connected to the load only with the load until a capacity reaches a predetermined lower limit;
When the capacity of the secondary battery connected to the load reaches the lower limit value, the secondary battery other than the secondary battery is disconnected from the charging unit and stored in the storage unit. a charge-discharge count minimum of the secondary batteries, a connection switching step of connecting the load,
When the capacity of the secondary battery is connected to the load it has reached the lower limit, viewing including the secondary battery, and a charging step of capacity to connect only the charging section to reach the highest,
When all of the plurality of secondary batteries have a capacity equal to or lower than the lower limit value and are not connected to the charging unit,
In the charging step, the secondary battery with the smallest number of charge / discharge cycles stored in the storage unit is connected to the charging unit until the capacity reaches the highest level,
In the connection switching step, the load is not connected to any of the plurality of secondary batteries, and then when the capacity of the secondary battery connected to the charging unit in the charging step reaches the highest level, While connecting the secondary battery to only the load,
When there is an instruction from a user, in the connection switching step, the secondary battery that is being charged and has the minimum number of charge / discharge cycles is connected to the load .

Images