JPS5814473A - Charging of sealed lead storage battery - Google Patents

Abstract

PURPOSE:To supply the insufficient charge caused due to short time chargings, and obtain a battery which has a stable and excellent charge-and-discharge cycle life by minimizing gas generation, and charging the battery with a current pattern set by a timer. CONSTITUTION:At the first stage, a lead battery is charged with a constant or semi-constant current until a given battery voltage is achieved, and the final battery voltage is determined so that the pressure of the internal produced gas becomes below the sealing pressure of a safety valve. At the second stage, a current is subjected to a scanning by using a CR circuit as a timer, and the value of the current is adjusted between the final charging current value of the first stage and the current value of the third stage. At this stage, voltage is uncontrolled although it depends on the capacity of the transformer of a charger, the pattern of a charging current doesn't change during the charge-and-discharge cycle, and an early capacity deterioration caused by the repetition of insufficient chargings is supplied by a compulsory charging. Following that, at the third stage, the current is switched to a micro-current, the current value is determined according to the overvoltage-resisting ability of the battery, and the voltage is uncontrolled. Thus charging of the battery is performed according to the above three stages. Consequently, the unstable charge-receiving performance of the battery is rectified in the second stage by charging the battery with the current pattern set by the timer, and gas generation is minimized.

Description

DETAILED DESCRIPTION OF THE INVENTION An object of the present invention is to provide a battery that compensates for insufficient charging during short-time charging of a sealed lead-acid battery and has a stable and excellent charge-discharge cycle life.

Conventionally, sealed lead-acid batteries require charging for 6 to 10 hours during repeated use. This is because constant current charging is practically impossible, and in constant voltage charging, the charging behavior in the section where the current is lowered after reaching a predetermined battery voltage affects the charge/discharge cycle life, and the time during this section. Therefore, as an attempt at short-term charging, (1) increase the maximum charging current in constant voltage charging, (2) increase the maximum charging current in constant voltage charging. At the same time, increase the constant voltage control voltage to a high value.

etc., but they have not been adopted for the following reasons: (a) The time for the current to drop after reaching the specified battery voltage is shortened, and due to repeated insufficient charging, PbSO, which is a reaction product from the discharge reaction
4 is not sufficiently oxidized to PbO2 and accumulates, resulting in early capacity deterioration.

(b) Since charging and discharging cycles are performed in an overcharged state, a large amount of electrolyte is lost, and 02 gas is easily absorbed by the cathode plate during charging, which prevents the charging current from decreasing and causes thermal runaway.

This phenomenon occurs because the charging current decreasing pattern in the constant voltage application region is regulated only by the charge acceptance characteristics of the battery, and this charge acceptance changes depending on the history of the battery, external conditions, etc. To.

This is due to things that cannot be controlled artificially.

The present invention compensates for the above disadvantages and provides a battery with an excellent charge/discharge cycle life. The specific charging method consists of the following three stages of control. That is, the first step is to charge the battery to a predetermined voltage with constant current or quasi-constant current. The final battery voltage at this stage is determined in advance at a point where the gas pressure generated inside the battery does not exceed the sealing pressure of the safety valve of the battery.

Second stage Next, the OR circuit is used as a timer to scan the current. The current at this time is 1st step. (7) The current value is 43 steps higher, that is, the current value is between the current value at the charging stage in the microminiature.

Also, at this time, the voltage is It depends on the capacity of the storage and is uncontrolled.

The charging current pattern at each stage does not change during the charge/discharge cycle, and forced charging compensates for early capacity deterioration caused by repeated undercharging caused by conventional constant voltage charging.

Third stage: Finally, the current is switched to a minute current.

The current value at this time is determined according to the overcharging ability of the battery. Also, as in the second stage, the voltage is uncontrolled. As described above, the gist of the present invention is to charge the battery according to the current change pattern set by the timer in order to correct the unstable charge acceptance of the battery in the second stage.

In this case it is desirable to select a current pattern that minimizes gas generation.

As shown in FIG. 1 as an embodiment of the present invention, 10 is 1
．． 3, Vc ut, 14. Set TV%TI to about 60 minutes, T2 to about 30 minutes, re to 0.06 mm, 12V at 10 1 hour rB] $2.0Ah.
When I combined a sealed lead-acid battery according to the specifications and charged it for 90 minutes and discharged it in about 90 minutes from 1o to 5'i, the second
As shown in the figure, it is more than 6 times as much as the constant voltage charging method.
The charge/discharge cycle life was more than three times longer than that of the time constant voltage charging method.

As described above, the charging method according to the present invention is an industrially extremely effective method that enables charging of sealed lead-acid batteries in a short time of 90 to 120 minutes, which has been difficult in the past, and also extends the battery life.

[Brief explanation of the drawing]

Figure 1 shows the initial characteristics of the charging method of the present invention, where M is the charging voltage behavior, B is the charging current behavior, %C is the voltage at constant voltage, and D
is the initial current behavior during constant voltage charging, Z is the current behavior after repeated undercharging during constant voltage charging, and Figure 2 shows the charge/discharge cycle characteristics. Those using a voltage charging method, and No. using a 6-hour constant voltage charging method. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure □ Period Figure 2 Charyo Bon-Hong (number of bad guys C times)

Claims (1)

[Claims] To charge a sealed lead-acid battery, the first step is to charge the battery to a predetermined battery voltage by constant current or quasi-constant current charging, and the second step is to charge according to a time and current pattern preset by a timer. A method for charging a sealed lead-acid battery, characterized in that a current is passed through the battery, and then, in the third stage, the current is switched to a minute current for charging.