JPH03282275A - Method for judging life of lead storage battery - Google Patents

Abstract

PURPOSE:To accurately judge life by measuring the ripple current contained in the charge current of the lead storage battery connected in a floating charge state through a rectifier and adding the measured current of an internal impedance measuring device to the ripple current. CONSTITUTION:A lead storage battery 3 is subjected to floating charge from a commercial power supply 1 through a rectifier 2. In this case, an AC ammeter 5 is inserted in the charging path of the lead storage battery 3. When the value calculated by dividing the ripple current measured by the AC ammeter 5 and the measured current of an internal impedance measuring device 6 by an addition current is displayed as internal impedance, the internal impedance in the floating charge state can be accurately measured. Therefore, by this method, the life of the lead storage battery can be accurately judged.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for determining the lifespan of a lead-acid battery, and more particularly to a method for determining the lifespan of a lead-acid battery used in a floating state.

Conventional technology and its problems Lead-acid batteries can be used for repeated charging and discharging when installed in electric vehicles, or used in a floating charging state when installed in emergency power supplies. There are known methods for determining the lifespan. In other words, for the former, the lifespan can be determined by measuring the change in terminal voltage during charging and discharging or by measuring the discharge capacity, but for the latter, it is prepared for emergencies, so
The former method cannot be used; lifespan is determined by measuring internal impedance. However,
When used in a floating charging state, a commercial power supply is used as the charging source 7, and the charge N current obtained through the rectifier contains a ripple current L current having a commercial frequency component.

Therefore, there is a drawback that the measurement current for measuring the internal impedance is affected by the ripple current described above, making the measurement value unstable.

OBJECT OF THE INVENTION The present invention solves the above-mentioned drawbacks, and is intended to solve the above-mentioned drawbacks, and to measure the voltage of a lead-acid battery by dividing the measured voltage by the measured current of the internal INVIDONE measuring device by the sum of the measured current and the ripple current contained in the charging current. The purpose is to obtain stable measurement values by precisely determining the internal impedance of the

Structure of the Invention The method for determining the lifespan of a lead-acid battery according to the present invention is a method for determining the lifespan by measuring the internal impedance of a lead-acid battery. Measure the ripple current caused by
A current measured by an internal impedance measuring device is added to this ripple current, a measured voltage due to this measured current is divided by the added current to calculate internal impedance, and the life is determined based on this calculated value. be.

EXAMPLE Prior to the explanation of the example, five new and end-of-life lead-acid batteries were tested.
When each is prepared one by one and put into an open state as shown in Figure 2,
As shown in Fig. 5, when the commercial power supply 1, rectifier 2, and load 4 are connected to create a floating charging state, each lead acid battery 3 is connected to an AC constant tffi source 6-1 and an AC voltmeter 6-2. When the internal impedance was measured by connecting an internal impedance measuring device 6 with a frequency of 60 fps and passing a constant AC current, the measured voltage was read by the AC voltmeter 6-2, and the internal impedance was measured as shown in Table 1. The results were obtained. For measurement in the floating charging state, the ripple current contained in the charging tX current is measured with an AC ammeter 5 before a constant AC current is applied as a measurement current, and then the measurement current is applied and an AC voltmeter 6-2 is used. The internal impedance was measured by reading the measured voltage and dividing the measured voltage by the sum of the ripple current and the measured current. Here, the end-of-life lead-acid battery was defined as a new battery that had been subjected to an overcharge life test of 0.0250 μm.

Margin below Table 1 From Table 1, the internal impedance in the open circuit state and
It can be seen that the internal impedance obtained by dividing the measured voltage in the floating charging state by the sum of the lip A/[current and the measured current] almost matches. Regardless of whether it is in an open circuit state or in a floating charge state, a new product has a calculated internal impedance of 0.45 MΩ to 0.45 Ω, and a life-span product has an internal impedance of 1. 2
It can be seen that it is 8111Ω to 1.3511Ω. From this, it can be seen that whether the battery is in an open circuit state or a floating charging state, if the internal impedance is 1.281 FlΩ or more, it can be determined that the battery life has expired.

The above experiment was conducted on other types of sealed FJ storage batteries and open type lead storage batteries, and similar results were obtained. Further, the constant current value and frequency of the measurement current in the above experiment are not particularly limited.

From the above experimental results, the present invention can be realized by a circuit as shown in FIG. That is, in Figure 1,
In a system for floatingly charging a lead-acid battery 3 from a commercial power source 1 via a rectifier 2, an AC 1 (
Insert the current meter 5, input the lip, A/ current measured by this AC ammeter 5IC and the measured current of the internal impedance measuring device 6 to the adder 7, and add the measured voltage by the measured current to the added current. By configuring the colors to display the value divided by the internal impedance, it is possible to accurately measure the internal impedance in the floating charging state.

Effects of the Invention As described above, the present invention can accurately determine the life span of a lead-acid battery used in a floating charging state.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram for realizing the lead-acid battery life determination method of the present invention, and FIG. 2 is a connection diagram of a lead-acid IF battery in an open state.
FIG. 3 is a connection diagram of a lead-acid battery in a floating charging state. 1... Commercial power supply 2... Rectifier 3... Lead-acid battery 4... Load 5... AC ammeter 6... Internal impedance measuring device 7... Adder

Claims (1)

[Claims] In a method of determining the lifespan of a lead-acid battery by measuring its internal impedance, the ripple current contained in the charging current of a lead-acid battery connected to a floating state of charge via a rectifier is measured, and this ripple current is subjected to an internal impedance measurement. 1. A method for determining the lifespan of a lead-acid battery, characterized in that the internal impedance is calculated by adding up the measured current of the device, dividing the measured voltage by the added current, and determining the lifespan based on this calculated value.