JPH053633A - Battery charging controller - Google Patents

Abstract

PURPOSE:To minimize the charging voltage stress by receiving a recharge rate data output from a recharge ratio counter and controlling the charging voltage and ensuring the recharge ratio requested. CONSTITUTION:When the total charged quantity up to now becomes equal to 1.0 to 1.3 times the discharged quantity discharge for a load 10 through a discharging diode 9 before charging, charging is considered to be completed, a charging completion signal 8 is output from a recharging ratio counter 7, and a trickle charging mode occurs. If the recharging ratio is predicted to be not fulfilling the set value within the remaining charging time based on the rising ratio of charging quantity for taper charging mode, the level of the constant-voltage charging voltage is increased or decreased for optimizing the recharging ratio. Thereafter, trickle charging current level occurs by the trickle charging mode. Battery charging state is held properly, and the charging voltage stress is minimized and battery life is extended by mixing the charging voltage as low as possible.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery charge control device, and more particularly to a battery charge control device for properly charging a solar cell used in an artificial satellite and the like and repeatedly discharging a load. .

[0002]

2. Description of the Related Art Generally, in a battery charging mode, the amount of charge from the state immediately after the first discharge is about 80.
The constant (full) charging mode of constant current charging for charging up to about%, the taper (taper) charging mode for charging to the final capacity value while decreasing the charging amount as the next step, and the self-discharge after this There is a trickle charging mode in which a small charging current is used for replenishment.
Further, as the charging control method in the above-mentioned taper charging mode, there is a constant voltage charging method that detects the overcharge voltage level of the battery and continuously reduces the charging current rate.

Conventionally, a battery charging control device for realizing such a constant current / constant voltage system in each charging mode is, as shown in the block diagram of FIG. 4, a power source 11, a charging unit 14 for controlling the charging current, and a charging unit. Battery 3, a voltage sensor 5 for detecting a battery charging voltage, a load 10 represented by a communication device, a discharging diode 9 forming a discharge path from the battery 3 to the load 10, and a current sensor 4 for detecting a charging / discharging current. It consists of and. Now, FIG. 2 (a),
A conventional example will be described with reference to various characteristics of battery charging voltage, charging current, and charging amount shown in the general explanatory diagrams of (b) and (c). The battery 3 is charged with electric power supplied from the power source 1 at a constant current controlled by a charging unit 14 that operates by receiving a signal corresponding to the detection voltage of the voltage sensor 5. This area corresponds to A of the full charge area in FIG. When the charging progresses and the battery voltage reaches a predetermined constant voltage shown at point E in FIG. 2A, the taper charging signal 6 is output from the voltage sensor 5 to the charging unit 14, and the taper charging signal 6 is output. 2), the charging current is continuously reduced while the charging voltage of the battery 3 is kept constant as shown by B in FIG. 2B. In the conventional example, the reduced current at the end of charging may vary depending on the set level of the overcharge voltage.

[0004]

The above-described conventional battery charge control device has a change in battery charge voltage characteristic over time and a change due to battery temperature. Therefore, the charge amount is optimized by initial setting of the overcharge voltage. There are drawbacks that are not easy. That is, there is a risk of insufficient charging or overcharging.

It is an object of the present invention to overcome the variation in the charging current in the taper charging region, maintain an appropriate charging state without excess or deficiency of charging, and minimize the stress due to the charging voltage. It is to provide a control device.

[0006]

SUMMARY OF THE INVENTION A battery charge control device of the present invention obtains a detection means for detecting a battery charge current and a discharge current, and a ratio of an integrated charge amount and an integrated discharge amount based on the charge current and the discharge current. When the value of the recharging rate reaches a predetermined threshold value, the operation determining means outputs a charging completion signal, and the charging mode is changed from taper charging or charging voltage control mode every time the charging completion signal is input. Current control means for charging current to switch to trickle charging mode, and charging to make the charging current necessary to secure the recharging rate defined by the remaining charging time from the rate of increase in the charging amount in taper charging or charging voltage control mode. And a charging voltage control means for performing voltage control.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings. 1 is a block diagram of an embodiment of the present invention, and FIG. 3 is a block diagram showing a configuration of the recharge rate counter 7 of FIG. In the present embodiment, the charging voltage control which receives the recharging rate data 12 output from the recharging rate counter 7 and outputs the signal 13 for controlling the charging voltage to operate so as to secure the required recharging rate. It has a unit 1 and a charging unit 2 that operates under the control of the recharge rate counter 7. Other configurations are the same as those of the conventional example of FIG.

Next, the operation of this embodiment will be described. The recharge rate counter 7 shown in FIG. 3 includes an integrator 15 for digitally counting the integrated value of the charge amount and the discharge amount, a memory 16 for storing the count value, and a ratio of the integrated charge amount and the integrated discharge amount. It has an operation judging device 17 which performs an operation and compares it with a predetermined value to judge it, and a charging completion signal generator 18 which outputs a charging completion signal which operates according to the signal of this operation judging device 17. Now, an amount obtained by integrating the current value of the current sensor 4 and time, that is, the total charge amount up to this point is 1 to 1 of the discharge amount discharged to the load 10 via the discharging diode 9 before this charge. When it reaches about 1.3 times, the recharge rate counter 7 outputs the charge completion signal 8 because the charge completion state is reached, and the trickle charge mode is set.
This mode shows a transition from B to D in FIG. 2B, and since the charging is performed at a charging current rate that is sufficient to supplement the self-discharge of the battery, there is no danger of overcharging. Further supplementally, the recharge rate counter 7 counts the value and time corresponding to the discharge current of the current sensor 4 when switching from charging to discharging, and stores the accumulated discharge amount from switching to discharging to charging. is doing. This discharge amount is compared with the charge amount integrated value of the next charge, and the recharge rate for each cycle of discharge and charge, that is, the ratio of the charge amount to the above-mentioned discharge amount is set to a numerical value in advance. It has a function of issuing a charging completion signal when the number of times reaches 1.3 times. If the recharge rate is predicted to be less than the set value within the remaining charge time based on the rate of increase in the charge amount with respect to the taper charge mode, the constant voltage charge voltage (see FIG.
As shown in FIG.
The recharging rate is optimized by setting the charging current characteristic in the region C in (b). Thereafter, the trickle charge mode is set to the trickle charge current level of D. By the operation as described above, the charge state of the battery is properly maintained. In addition, by reducing the charging voltage as much as possible, the charging voltage stress is minimized to maintain the life of the battery. Also,
After charging for a while in the F area, check the rate of increase in the amount of charge, and if it is determined that the recharge rate is not sufficient for the remaining charging time, raise the level to E again to increase the amount of charge. The securing operation is performed automatically.

[0009]

As described above, the present invention is provided with the recharging rate counter and the charging voltage control section for comparing the previous accumulated discharge amount and the next accumulated charge amount to judge the excess or deficiency of charging. Therefore, there is an effect that a proper charge state can be accurately maintained. Further, the upper limit setting of the charging voltage is not required to be strict, and the charging voltage stress is applied only for a minimum time. Therefore, there is an effect that it is possible to provide a battery charge control device capable of holding the battery life longer.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention.

FIG. 2 is a general explanatory diagram showing charging characteristics of a battery.

FIG. 3 is a block diagram of a recharge rate counter of the present embodiment.

FIG. 4 is a block diagram of a conventional battery charge control device.

[Explanation of symbols]

1 Charge voltage controller 2,14 Charging section 3 battery 4 Current sensor 5 voltage sensor 6 Taper charge signal 7 Recharge rate counter 8 Charge complete signal 9 Discharge diode 10 load 11 power supply 13 Charge voltage control signal 15 Accumulator 16 memory 17 Operation decision device 18 Charge complete signal generator

Claims (2)

[Claims] 1. A detection means for detecting a battery charging current and a discharging current, and a value of a recharging rate obtained by the ratio of the integrated charging amount and the cumulative discharging amount by the charging current and the discharging current is a predetermined threshold value. A calculation determining unit that outputs a charging completion signal when the value reaches a value, and a current control unit for charging current that switches the charging mode from the taper charging or the charging voltage control mode to the trickle charging mode each time the charging completion signal is input, Charging voltage control means for performing charging voltage control so as to obtain a charging current required to secure a recharging rate determined by the remaining charging time from the rate of increase in the charging amount in the taper charging or the charging voltage control mode. Characteristic battery charge control device. 2. The integrator for digitally counting the integrated charge amount and the discharged amount from the charge current and discharge current of the detector, the memory for storing the count information of the integrator, and the memory of the memory. Completion of charging by an operation judging device for judging that the value of the recharging ratio has reached a predetermined threshold value indicating completion of full charging by accumulating the recharging ratio from information, and a judgment signal of the calculation judging device. The battery charge control device according to claim 1, further comprising a charge completion signal generator that outputs a signal.