JPS6022424A - Charge acceleration indicator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a charging reminder display device that displays the remaining capacity of a secondary battery.

[Background technology]

Conventional methods for calculating the remaining capacity of secondary batteries include JP-A-5
As seen in Publication No. 7-88678, there was a method in which the discharge capacity was calculated from the 1+1 discharge current, and the discharge capacity was subtracted from the charge capacity to calculate the remaining capacity. However, in such conventional examples, the self-discharge of the battery itself Since this method does not take any consideration into consideration, it has the disadvantage that it is useless if left for a long period of time.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned points, and its purpose is to make it possible to visually check the remaining capacity of a secondary battery.
To provide a charging reminder display device that can easily determine how much longer a device using a secondary battery can be used, also know when charging is required, and improve the usability of a device using a secondary battery. [Disclosure] Fig. 1 shows a circuit block of an embodiment of the present invention, and in the figure (1) is a charging circuit that obtains a predetermined charging current from an alternating current power supply AC. The charging current flows to the secondary battery (2) via the charging operation switch SWc and the charging current measuring resistor R1. (3) is a load such as Tanabata used as a battery-powered device (2), and the load (3) is connected to the secondary battery (2) via the load operation switch SWD and the discharge current measuring resistor R2. be done. (4) is an arithmetic circuit like a microcomputer that serves as a storage means and a calculation means, and this arithmetic circuit (4) is connected to the charging operation switch SW.
c is closed and the charging current flows through the charging current measuring resistor R, and the voltage generated is taken in as charging source data via the converter (5). In this case, the arithmetic circuit (4) calculates An=An-1+IoXΔtXK, and stores the integrated value of the charging current, which is the charging capacity. Here, An is the current integral value of the charging current, An-1 is the integral value before the l sampler, Io is the detected value of the charging current calculated by the above-mentioned voltage conversion, and Δt is the period of the charging current.

K is the charging efficiency that changes depending on the temperature, and this charging efficiency is calculated from the temperature detected by the temperature secessor (6) arranged to be thermally coupled to the secondary battery (2) by the calculation circuit (4).
). When the charging operation switch SWc is opened and charging is completed, the arithmetic circuit (4) stores the charging capacity An calculated at that time as the remaining capacity BO.

In addition, the arithmetic circuit (4) converts the voltage generated when the load operation switch SWn is closed and the discharge current flows through the discharge current measurement resistor R1 into discharge source data via the A/I converter (7). The remaining capacity Bn is sequentially calculated.

In addition, when the secondary battery (2) is left for a certain period of time or more after charging, the arithmetic circuit (4) calculates a differential coefficient Cn (self-discharge (equivalent to current) and subtracting its time product, the remaining amount Jit Bn ? il- is calculated.

In the figure, (8) is a remaining capacity indicator which is also a display means, and this remaining capacity indicator (8) is connected to the arithmetic circuit (4) during charging and discharging.
This is for sequentially displaying the current capacity of the battery (2) based on display data from.

Next, the operation of this apparatus will be explained based on the flowchart shown in FIG.

Now, when the charging operation switch SWC is turned on and charging is started in step ■, the arithmetic circuit (4) takes in the temperature data from the temperature sensor (6) and calculates the charging efficiency K in step ■. The charge capacity A+n is calculated in step (2) by combining the charge current with the integral value of the charging current. This charging capacity An
The results are transferred to the remaining capacity display (8) as display data, and the current charging capacities A and n are successively displayed at step Step 0 is performed until the switch SWc is opened.
When it is determined that the charging operation switch SWC is opened, the arithmetic circuit (4) stores the charging capacity An as the remaining capacity Bo in step (3).

Next, charging (■); If it is determined in step 1 that both the operation switch SWC and the load operation switch SWo have been left open for a predetermined time T (for example, 5 days), the discharge shown in FIG. Determine the self-discharge function depending on the characteristics in step ①, determine the differential coefficient Cn at the predetermined remaining capacity Bn in step ②, and calculate the remaining capacity Bn due to self-discharge as Bn =
It is calculated in step (2) using Bn-1-CnXΔt. Here, Δt is the sampler amount, and Bn-1 is 1
It shows the remaining capacity before the sun printer, and Bn shows the current remaining capacity. Now, when the remaining capacity Bn is full, the arithmetic circuit (4) determines whether the remaining capacity Bn is zero (here, the capacity at which the load (3) cannot operate) or not using Stella "jap", and determines that it is not zero. In this case, both operation switch SWc or SW
It is determined in step (i) whether either one of D is in the closed state, and if it is not in the closed state, the process returns to step (2) and the operating state is determined to calculate the remaining capacity due to self-discharge as described above. The loop of steps ①, CD, and 6 continues until the remaining capacity Bn becomes zero.When it is determined that the remaining capacity Bn is zero in step ②, the arithmetic circuit (4) No arithmetic operation is performed until the start of the next charging, and the process ends at 0.

Now, while calculating the remaining capacity due to self-discharge or between the end of charging and the start of calculating the remaining capacity due to self-discharge, the double operation switch SWC
1 or SWo is closed, it is determined in step 0 whether the closed switch is the charging operation switch SWc or the load operation switch SWo, and if the charging operation switch SWC is closed, the above step is performed. Return to ■. Further, if the load operation switch SWo is closed, the arithmetic circuit (4) transfers the power from the battery (2) to the load (3).
) and the discharge current flowing through the discharge current measuring resistor R2, the time product of the discharge current is calculated based on the voltage across the discharge current measuring resistor R, and the remaining capacity Bn is calculated as Bn = )3n −
1-I. Calculate by ×Δt and restep [phase]. Here I. is the discharge current value, Δt is the sampling amount, Bn-
1 indicates the remaining capacity of one sample printer song. The calculation results are successively displayed on the remaining capacity display (9).

Step 0 is a routine that determines whether the remaining capacity of the battery (2) has reached zero (corresponding to the remaining capacity at which the load (3) cannot operate), and if this judgment is YES, step t1:3
Proceed to + and end with 0 jiram. The judgment is N again
.

If so, determine whether the step boiling load operation switch SWo is in the open state, and if NO, step 0.
If the answer is YES, the process returns to step (2).

〔Effect of the invention〕

As described above, the present invention includes a storage means for calculating and storing a charging capacity by integrating a charging current flowing from a charging circuit to a secondary battery;
Calculating means for calculating the discharge capacity from the secondary battery to the load by integrating the discharge current, calculating the self-discharging capacity of the secondary battery, and subtracting it from the charging capacity stored in the storage means to calculate the remaining capacity; , and a display means for displaying the remaining capacity calculated by the calculation means, so that the remaining capacity taking self-discharge into consideration can be displayed by the display means even when the device using a secondary battery is not used for a long time. From this, it is possible to reliably and easily determine how much longer a device using a secondary battery can be used, and also know when it needs to be charged, allowing for systematic charging and eliminating wasted charging time. This has the effect of improving the usability of devices using secondary batteries.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram of an embodiment of the present invention, Fig. 2 is a discharge characteristic diagram of a secondary battery using the same as above, and Fig. 8 is a discharge characteristic diagram of a secondary battery using the same as above. ) is a secondary battery, (3)
is a load, (4) is an arithmetic circuit, and (8) is a remaining capacity indicator. Agent Patent Attorney Ishi 1) Choshichi

Claims (1)

[Claims] (1) A storage means for calculating and storing the charging capacity by integrating the charging current flowing from the charging circuit to the secondary battery; A charging reminder comprising a calculation means for calculating the self-discharge capacity of the next battery and subtracting it from the charge capacity stored in the storage means to calculate the remaining capacity, and a display means for displaying the remaining capacity calculated by the calculation means. Display device.