JPH0648290B2 - Power supply unit with life indication of sealed lead-acid battery - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply device, and more specifically, to a power supply device that supplies DC power to a load while floatingly charging a sealed lead storage battery. The battery life indicator is provided to improve reliability.

2. Description of the Related Art Conventional technology and its problems Many power supply devices that supply DC power to a load while floating-charging a storage battery are using a sealed lead storage battery in response to the demand for maintenance-free operation. In recent years, the capacity of the sealed lead-acid battery has also increased, and the number of power supply devices equipped with the sealed lead-acid battery of large capacity has increased, and it has become possible to cope with various loads. However, the sealed lead-acid battery is known to have a great effect on its life depending on its usage conditions, that is, floating charging voltage, ambient temperature, etc., and therefore, it may be unreliable for an important load.

The object of the present invention is to solve the above-mentioned drawbacks by approximating the change characteristics of the life of a sealed lead-acid battery charged with a constant floating charging voltage with ambient temperature with a polygonal line and responding to this polygonal line at each ambient temperature. The purpose is to enable accurate replacement of sealed lead-acid batteries by counting the remaining pulses and displaying the remaining life.

The present invention relates to a sealed lead acid battery configured to be charged by a charging device at a floating charging voltage of 2.275 V / cell at an ambient temperature of 20 ° C., and a DC output is supplied to a load, and a life display portion thereof. In a power supply device equipped with a life indicator of a sealed lead acid battery, the ambient temperature T of the sealed lead acid battery is
The change characteristic of the life due to the constant value C when the ambient temperature T is 5 to 30 ° C.
b, if the ambient temperature T is 5 ° C. or lower, the curve is approximated by a polygonal line −ap′T + b ′, and the number of pulses or the pulse generation period corresponding to the life change characteristic approximated by this polygonal line is stored. A ROM that outputs a pulse stored based on the ambient temperature of the sealed lead-acid battery, a counter unit that counts the pulses output from this ROM and sends a signal when the count value reaches a predetermined value, The present invention is provided with a sealed lead-acid battery life display unit, which is provided with a display unit that displays a sealed lead-acid battery life indication or a life advance notice display according to a signal from the counter unit.

Examples Hereinafter, examples will be described. FIG. 1 is a block diagram of a power supply device according to the present invention. The basic configuration is an AC input terminal 1 to which an AC power supply is connected, and a charging device 2 that receives this AC and outputs DC having a constant voltage constant current characteristic. , This charging device 2
It is composed of a sealed lead-acid battery 3 which is floatingly charged by, a load 4 to which the direct current is supplied, and a load terminal 5. The load 4 is an inverter if it obtains an AC uninterruptible output at the load terminal 5, and a load voltage compensator if it obtains a highly accurate DC voltage at the load terminal 5. A feature of the present invention is that a temperature sensor 7 that detects the ambient temperature in an analog manner is attached in the vicinity of the sealed lead-acid battery 3 of the main circuit portion 6 of the power supply device as described above, and is charged with a constant floating charging voltage. ROM 8 in which the characteristics of the change in the life of the sealed lead-acid battery 3 according to the ambient temperature are approximated by broken lines and stored.
Is provided, and the ROM 8 outputs pulses of a number or a generation cycle corresponding to the change characteristic of the life at the ambient temperature. The output pulse is input to the counter unit 9 and counted, and when the count value reaches a predetermined value, a signal is sent to the display unit 10. This predetermined value is set to 100% in the case of displaying the life of the sealed lead-acid battery 3 and 80 to 90% in the case of displaying the life notice, and the corresponding display is displayed on the display unit 10. . R mentioned above
The OM 8 is equipped with a backup power supply 11 to prevent data loss due to a power failure or the like. The temperature sensor 7, the ROM 8, the counter unit 9, and the display unit 10 can be reduced in size, weight, and cost due to the progress of integrated circuit technology and the like.
The reliability of the power supply device can be improved only by attaching the to the sealed lead-acid battery 3.

Next, the principle will be described. The broken line in Fig. 2 shows the relationship between the ambient temperature and the maximum guaranteed value and the minimum guaranteed value of the life when the floating charge voltage of the sealed lead-acid battery is 2.275V / cell at 20 ° C, and the capacity is the rated capacity. The life is determined when it reaches 80%. It can be seen from FIG. 2 that if the ambient temperature is 5 to 30 ° C., the minimum life guarantee value is reached in about 3 years, and if the ambient temperature is 30 ° C. or higher and 5 ° C. or lower, all become linearly short. Based on this characteristic, the change characteristic of the life with respect to the ambient temperature is approximated by a broken line like the solid line in FIG. 2, and this characteristic is stored in the ROM 8 and
The number of pulses corresponding to the change characteristic is output from the ROM 8. That is, the number P of pulses output from the ROM 8 is 5 when the ambient temperature is 5 as shown by the alternate long and short dash line in FIG.
A constant value C if -30 ° C, P = a if 30 ° C or higher
If T + b is 5 ° C. or lower, the configuration is such that it increases linearly as P = −a′T + b ′. (T: ambient temperature) For example, the number of pulses output from the ROM 8 is 1
If you use 1 pulse per second, the life will be 1 year in continuous use at -10 ℃, so the number of pulses is 60 × 60 × 24 × 365.
When it reaches 31,536,000, the life is displayed, and 8
0 to 90% of 25,228,800 to 28,382,400 will be displayed in advance to display the service life.

The flow chart of the above principle is as shown in FIG. That is, the number of pulses is weighted according to the ambient temperature T.

Although the number of pulses is weighted according to the ambient temperature T in the above embodiment, the same effect can be obtained by weighting the pulse generation period. In this case, if the ambient temperature is 30 ° C. or higher and 5 ° C. or lower, the pulse generation period may be linearly shortened.

Effect of the Invention As described in detail in the embodiments, the power supply device of the present invention can accurately display the life of the sealed lead-acid battery incorporated therein, and thus the reliability of the device can be improved.

[Brief description of drawings]

FIG. 1 is a block diagram of a power supply device of the present invention, FIG. 2 is a diagram for explaining the principle of the device of the present invention, and FIG. 3 is a flow chart of the device of the present invention. 2 ... Charging device, 3 ... Sealed lead acid battery, 4 ... Load 7 ... Temperature sensor, 8 ... ROM, 9 ... Counter section 10 ... Display section, 11 ... Backup power supply

Claims (1)

[Claims] 1. A sealed lead-acid battery configured to be charged by a charging device at a floating charging voltage of 2.275 V / cell at an ambient temperature of 20 ° C. and to be supplied with a DC output to a load, and a life indicator thereof. In a power supply device equipped with a life indicator for a sealed lead acid battery, the change characteristics of the life of the sealed lead acid battery with the ambient temperature T are shown as a constant value C and an ambient temperature T of 30 if the ambient temperature T is 5 to 30 ° C. AT above ℃
+ B, if the ambient temperature T is 5 ° C. or lower, the curve is approximated by a polygonal line −a′T + b ′, and the number of pulses or the pulse generation period corresponding to the life change characteristic approximated by this polygonal line is stored. A ROM that outputs a pulse stored based on the ambient temperature of the sealed lead-acid battery, a counter unit that counts the pulses output from this ROM and sends a signal when the count value reaches a predetermined value, A power supply device having a life indicator of a sealed lead storage battery, which is provided with a display portion for displaying a life indication or a life advance notice of the sealed lead storage battery according to a signal from a counter portion.