JPH04150727A - Battery pack - Google Patents

Abstract

PURPOSE:To inform start of charging operation and necessity of interruption of the charging operation quickly and accurately by detecting the direction and the magnitude of current, variable with time, to be charged/discharged to/from a rechargeable battery, accumulating thus detected current with time and calculating accumulated amount of electricity charged/discharged to/from the rechargeable battery within a predetermined time. CONSTITUTION:An operational amplifier 12 sets the polarity of current negative when the current flows downward through a resistor 13, i.e., at the time of discharge, while sets the polarity of current positive at the time of charging. When the output voltage of the operational amplifier 12 is applied on a series circuit of a high resistor 13 and a low capacitor 14, output voltage accumulated with time is generated as a voltage for the ground point of the capacitor 14. The voltage is compared through a comparator 16A with the voltage of a positive constant voltage supply 18 while furthermore compared through a comparator B17 with the voltage of a negative constant voltage supply 19. When any one voltage level is reached, a signal is fed to a central operating unit 2 and an electric amount accumulating counts up or down and a capacitor discharge switch 15 is temporarily turned ON.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is directed to electric equipment using rechargeable batteries as a power source.

This invention relates to a battery pack that is effective in preventing overcharging.

Conventional Technology Generally, in order to detect the remaining amount of electricity in a rechargeable battery, the voltage of the battery is determined during discharging, the charging time during charging, and the characteristics of the battery and the charger. Moreover, no measures were taken for the battery pack itself to prevent a decrease in power supply capacity, over-discharge, and over-charge.

Problems to be Solved by the Invention When using the above conventional battery pack, the voltage is determined based on the voltage of the battery when discharging, the charging time when charging, the characteristics of the battery, and the characteristics of the charger. However, since the relationship between the remaining amount of electricity in the battery and the voltage is generally shown in FIG. 4, the following problems arise.

When discharging, the remaining amount of electricity has dropped to a value that requires charging, which is a stable condition as shown in Figure 4! ! 63, it cannot be detected and can only be detected when the voltage drops to the voltage drop state 62.

In this case, if charging is not performed immediately, the voltage will further drop. If charging cannot be performed immediately, the performance of the device to which power is supplied will not be achieved. Further, if the discharge is continued further, an overdischarge 51 is reached, resulting in deterioration of the battery.

Furthermore, if charging is started in the stable state a53, the remaining amount of electricity cannot be determined from the voltage, and therefore the necessary charging time cannot be determined. At this time, if the required amount of charging is performed in the voltage drop state 52, overcharging 64 will be reached.
This also results in battery deterioration.

The present invention solves the above-mentioned conventional problems.By constantly detecting the amount of electricity held by the battery, it is possible to quickly and accurately notify the need to start or stop charging, and to prevent the amount of electricity from decreasing. The purpose is to provide a battery that can supply the rated voltage for a certain period of time even if the battery is punctured.

Means for Solving the Problems In order to achieve the above objects, the present invention provides a battery mounting connection means for accommodating a rechargeable battery, a time-varying direction of current that is charged or discharged to the rechargeable battery, A current detection means for detecting the magnitude, an integration means for integrating the current value detected by the current detection means with respect to time, and a cumulative value of the integration means is calculated. calculates the cumulative amount of electricity charged and discharged to the rechargeable battery, determines the remaining amount of electricity in the rechargeable battery, and warns that charging needs to be started or interrupted according to the characteristics of the battery given in advance. a central processing unit that emits a signal, a display device that displays information output from the central processing unit to the outside or emits an electrical signal, and a battery type input device that provides information such as the type of battery being used to the central processing unit. If necessary, a constant voltage means for boosting or lowering the voltage of the rechargeable battery and supplying the rated voltage to external equipment is added.

Effects of the present invention By adding means for integrating and accumulating the current value charged in the rechargeable battery over time and a constant voltage means, the remaining amount of electricity can be constantly detected, and the charging can be started. The user is quickly and accurately notified of the necessity of termination, and in a configuration that includes a constant voltage means, even if the battery voltage drops, a constant voltage can be supplied to external equipment for a certain period of time.

Embodiment Hereinafter, the structure and operation of an embodiment of the present invention will be explained with reference to the drawings.

In FIG. 1, the rechargeable battery \7 is the battery mounting connection means 6.
It is attached and connected to the battery pack A by the battery pack A, and is charged by the charger 8 when charging, and supplies power to the electrical equipment 10 when discharging. The voltage of the electric power supplied to the electrical equipment 10 is kept constant by military stabilizing means 9. The magnitude and direction of the current charged and discharged to the rechargeable battery 7 are detected by the current detection means 6. The current detected by the current detection means 5 is integrated over time by the integration means 4.

The central processing unit 2 calculates the amount of electricity of the rechargeable battery 7 by calculating the cumulative value of the charge amount and discharge amount integrated by the integration means 4, and calculates the amount of electricity that the rechargeable battery 7 has, and selects the battery type selected by the battery type input device 1. Based on the characteristics of the battery, it is determined whether it is necessary to start or stop charging. Next, referring to FIG. 2, the integration means 4
is composed of a high resistance 13 voltage source 19. The current detection means 6 is composed of a low resistance 11 and an operational amplifier 12 shown in FIG. It has a function of converting the current value discharged toward the air equipment 10 into a voltage proportional to the current value. Voltage detection means 2
0 measures the terminal voltage of the rechargeable battery 7 and outputs it to the central processing unit 2.
It has the function of communicating.

When a current flows through the rechargeable battery 7, the same amount of current flows through the low resistance 11, and a proportional voltage is generated with respect to the ground point. This voltage is amplified by the operational amplifier 12 and applied to the integrating means 4. The polarity of the operational amplifier 12 is set so that in FIG. 2, when the current flows from top to bottom with respect to the low resistance 13, it has a negative output when discharging, and has a positive output when the current flows reversely when charging.

Next, when the output voltage of the operational amplifier 12 is input to a series circuit of a high resistance 13 and a low capacitance capacitor 14, an integral value of the output voltage with respect to time is generated as a voltage with respect to the ground point of the capacitor 14.

This voltage value is the voltage value of the positive constant voltage source 18 and the comparator A1e.
The voltage value of the negative constant voltage source 19 and the comparator B
17, and which voltage value the voltage value of the capacitor 14 reaches is transmitted to the central processing unit 2. At this time, the central processing unit 2 increments/decreases its own electrical quantity cumulative counter, turns on the capacitor discharge switch 15 for a short time, and sets the voltage to the ground point of the capacitor 14 to zero. Therefore, the lower limit of the voltage applied to the capacitor 14 is the negative constant voltage source 19. Upper limit is positive voltage source 1
Although the amount of electricity charged and discharged is limited to a range of 8, the amount of electricity charged and discharged can be determined in an unlimited range.

Next, the operation of the central processing unit (FIG. 1, FIG. 2) will be explained with reference to the flow chart in FIG.

When the central processing unit is initialized and started by replacing batteries, etc., in step 31 it reads the battery type from the battery type input device 1, stores this in the central processing unit itself, and initializes the counter for the cumulative value of electricity. do. At this time, the user inputs into the battery type input device the type of battery and whether or not the battery is fully charged when inserted. If it is input that the battery is fully charged, the amount of electricity at full charge for the battery type set in the central processing unit is set, and the remaining amount of electricity is measured from that point on. The operation when inputting that the battery is not fully charged will be described later. Next, the process proceeds to step 32, where the capacitor shorting switch 16 is turned on for a short time to short-circuit the capacitor 14, that is, to initialize it. This completes the initial settings.

Next, in step 33, the output of the comparator B17 is checked, and in step 34, it is checked whether the integrated value of the current has reached the lower limit (negative constant voltage source 19). If it has not been reached, jump to step 39. If the lower limit has been reached, proceed to step 36 and turn on the capacitor shorting switch 15 for a short time, turning the capacitor 14 on.
Short-circuit, that is, initialize. Next, in step 36, the electric quantity cumulative value counter is decremented to reduce the cumulative quantity. Next, in step 37, the battery characteristics inputted and the cumulative amount of electricity are compared, and it is determined whether the battery has reached a level at which it is necessary to issue a charging start warning. If not necessary, jump to step 39.
If necessary, a charging start warning is output to the display device 3 in step 38. At this time, if the charger 8 is connected to the battery pack A, the central processing unit 7 or the display device 3 instructs the charger 8 to charge.

Following the processing in step 38, in step 39 the comparator A
The output of 1e is checked, and in step 40 it is checked whether the integrated value of the current has reached the upper limit (positive constant voltage source 18). If it has not been reached, the process returns to step 33. If the lower limit has been reached, the process proceeds to step 41, where the capacitor shorting switch 16 is turned ON for a short time, and the capacitor 14 is shorted, that is, initialized. Next, in step 42, the electricity quantity cumulative value counter is incremented to increase the cumulative value, and in step 43, step 3
The battery characteristics input in step 1 are compared with the cumulative amount of electricity, and it is determined whether the battery has reached a level that requires a charging stop warning to be issued. If it is not necessary, the process returns to step 33; if necessary, a charging stop warning is output to the display device 3 in step 44, and then the process returns to step 33. At this time, battery pack A
If the charger 8 is connected to the charger 8, the central processing unit 7 or the display device 3 instructs the charger 8 to stop charging.

If it is input in step 31 that the battery is not fully charged, and the terminal voltage of the rechargeable battery 7 measured by the voltage detection means 2o is in the overdischarge state 61 or the voltage drop state 62 in FIG. Since it is calculated, it is set in the central processing unit and the remaining amount of electricity is measured from that point on.

If it is input in step 31 that the charge is not fully charged and the voltage is in the stable state 63 or the overcharge state 64 in FIG. The charging warning will not be issued until the When the voltage lowering means 62 reaches -degrees, the remaining amount of electricity is determined, and henceforth the remaining amount is measured and a charging and charging stop warning is issued.

In addition, if a battery is used that has a lower amount of electricity when fully charged than the initial one due to battery deterioration, the central processing unit 2
The voltage detection means 2o may detect the voltage reduction means 62 before the charging warning is issued.In that case, the remaining amount of electricity is corrected at that time, a charging warning is issued, and from then on, the voltage at full charge is The amount can be corrected.

An example has been shown above, but the charging start/stop warning is as follows:
Not only when the remaining amount of electricity reaches one value,
It goes without saying that the central processing unit can be set to display multiple values at different warning levels.

In addition to displaying a warning to start/stop charging with sound or light, the display device can also send an electrical signal to the outside, and the processing can be determined by an external device. It is also possible to set the central processing unit 2 to calculate the discharge amount of the battery 7 by taking into account not only the flowing current but also the natural discharge amount.

Effects of the Invention As is clear from the above embodiments, according to the present invention, the remaining amount of electricity in the battery can be known at all times, and the voltage applied to the electrical equipment can be kept constant. Therefore, it is possible to promptly and accurately notify that charging needs to be started and ended, and it is possible to prevent a decrease in power supply capacity, over-discharge, and over-charge. In addition, in a configuration with a constant voltage means, it is necessary to start charging, and even if charging is not performed despite a warning and the battery voltage drops, the external device will not be able to maintain the constant voltage for a certain period of time. Can supply voltage.

[Brief explanation of drawings]

FIG. 1 is a block diagram of the main parts of an embodiment of the present invention, and the part surrounded by broken lines constitutes a battery pack. Figure 2 is a circuit diagram of the main part of the part that integrates current over time and calculates the cumulative total, Figure 3 is a flowchart showing the processing procedure of the central processing unit, and Figure 4 is a diagram of a typical battery. FIG. 3 is a characteristic diagram showing the relationship between the remaining amount of electricity and the output voltage. DESCRIPTION OF SYMBOLS 1...Battery type input device, 2...Central processing unit, 3...Display device, 4...River/integration means, 5...Mountain/current detection means, 7...Battery, 9
... Constant voltage means, A ... Battery pack. Name of agent: Patent attorney Akira Okaji et al.26 Figure Figure Figure

Claims (3)

[Claims] (1) A battery storage means for storing a rechargeable battery, a current detection means for detecting the direction and magnitude of a temporally varying current that is charged or discharged into the rechargeable battery, and detection by the current detection means. an integrating means for integrating the current value over time; and calculating the cumulative amount of electricity charged and discharged into the rechargeable battery within a predetermined time by calculating the cumulative value of the integrated value of the integrating means. a central processing unit that determines the remaining amount of electricity in the rechargeable battery and issues a warning that charging needs to be started or interrupted according to predetermined characteristics of the battery; and information issued by the central processing unit. A battery pack comprising: a display device for externally displaying or emitting an electric signal; and a battery type input device for inputting information such as the type of battery being used to the central processing unit. (2) The battery pack according to claim 1, further comprising a constant voltage means for increasing or decreasing the voltage of the rechargeable battery and supplying the voltage to an external device. (3) The battery pack according to claim 1, further comprising voltage detecting means and configured to correct an error with the remaining amount of electricity obtained by the integrating means.