JPS633539B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a storage battery charging control method,
In particular, the purpose is to improve reliability and extend the lifespan of sealed nickel-cadmium storage batteries when rapidly charging them.

The charging control method for rechargeable batteries, especially sealed nickel cadmium storage batteries, requires
There are known methods of controlling charging by detecting temperature, amount of electricity, etc., and a method of detecting temperature using a temperature-sensitive magnetic switch has also been proposed. However, all conventional temperature controls only have a method of controlling and stopping charging when the battery temperature rises and reaches a certain value, and no consideration has been given to cases where the battery temperature is excessively low.

In general, in rechargeable batteries, the lower the temperature (below 0°C), the higher the rate of gas generation inside the battery, and conversely the gas absorption capacity decreases, so the internal pressure of the battery at room temperature (10~
30℃). Therefore, if charging at low temperatures below 0° C. is repeated, the safety valve of the battery will operate more frequently, causing a problem in that the battery life will be shortened due to a decrease in the amount of electrolyte.

The present invention solves these problems by using a temperature-sensitive element having set temperatures T ₁ and T ₂ on the low-temperature side and high-temperature side as the energization control element.

The present invention will be explained below using a sealed nickel cadmium storage battery as an example. KR-C of JISC8705
Connect 10 size batteries in series, and
It is stored in a storage case made of ABS resin, and the outer case of one cell inside the case has a temperature of -10
A temperature-sensitive reed switch was wired as shown in FIG. 1, which turned off at temperatures below 0°C, turned on at temperatures above 0°C and below 45°C, and turned off again at temperatures above 45°C and 50°C. In the figure, 1 is a DC power supply, 2 is a switching circuit, 3 is a control circuit, 4 is a battery, 5 is a storage case, and 6 is a temperature sensing element.

By configuring the charging control circuit of the present invention as shown in the figure, when the battery temperature is lower than the low temperature set temperature _T1 or higher than the high temperature set temperature _T2 , the temperature sensing element turns off even if the battery is connected to the charging circuit. Since the charging current to the battery is stopped in this state, it is possible to prevent acceleration of battery deterioration due to an abnormal increase in battery internal pressure due to rapid charging outside the appropriate temperature range.
The conventional charge control system using a thermosensor that detects only the high temperature side and the one using the thermosensor of the present invention that detects both low and high temperatures are used in the temperature cycle and charge/discharge pattern shown in Figure 2. ,Each
When a charge/discharge test was conducted at 1CA, the battery capacity characteristics were 80 for the conventional product and 100 for the product of the present invention, as shown in Figure 3. The relationship between charge air volume and battery internal pressure during charging is as shown in Figure 4, where A indicates the ambient temperature of -10℃, B indicates 5℃, C indicates 20℃, and D indicates the safety valve operating pressure range. show.

As is clear from this, the present invention can control rapid charging when the battery is at an abnormally low temperature or abnormally high temperature, using a single temperature sensing element, without the need to make any additional changes to the conventional charging control circuit. , it is possible to self-prevent deterioration of battery performance due to such abnormal usage.

[Brief explanation of the drawing]

Figure 1 is a wiring diagram of a temperature-sensing charging control circuit according to an embodiment of the present invention, Figure 2 is a diagram showing temperature cycle test conditions, Figure 3 is a diagram showing temperature cycle test results, and Figure 4 is a diagram showing the battery. FIG. 3 is a diagram showing internal pressure characteristics during charging. 1...DC power supply, 2...Switching circuit, 3
...Control circuit, 4...Battery, 5...Storage case,
6... Temperature sensing element.

Claims (1)

[Scope of Claims] 1. A charging method using an energization control element that is attached to a storage battery to be charged and that detects battery temperature and controls charging current, wherein the energization control element has a low-temperature set temperature T. A storage battery charging control method characterized by using a temperature sensing element that loses its coercive force and opens its contacts at a set temperature T of ₁ or higher and a high temperature set temperature T _{of 2} or higher. 2. The storage battery to be charged is a sealed nickel cadmium storage battery, and the low temperature set temperature of the temperature sensing element is -10 to 0°C, and the high temperature set temperature is 45 to 50°C.
A storage battery charging control method according to claim 1.