JPH0850925A - Charging method for lead-acid battery - Google Patents

Abstract

PURPOSE:To shorten the time during which a charging voltage is applied to the battery, and prolong the life of the battery by carrying a floating charge operation in two steps at specified constant currents respectively, letting a specified dormant time be admitted in a charging process, and letting charging time and the specified dormant time be interchangeably repeated. CONSTITUTION:In an application employing an intermittent trickle or an intermittent float where time for floating charge and dormant time are interchangeably repeated, a floating charge operation is carried out with constant currents changed in two steps. Charging current for a first step shall be of a value exceeding an allowable charging current, and is shifted to a second step for charging at the time when charging voltage reaches a specified one. Charging current for the second step shall be less than the allowable charging current, let charging be suspended for the period of more than 15 days at the time when charging voltage reaches a specified one which is lower than a specified voltage for the first step. By this constitution, self-charging during a dormant period can neither more nor less charged, and concurrently a charging operation at the time of charging can thereby be efficiently carried out, so that life performance can be enhanced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for charging a lead storage battery.

[0002]

2. Description of the Related Art There are two types of charging methods for lead-acid batteries used as emergency standby power sources. One is to constantly charge the battery with a small amount of current while supplementing self-discharging, and requiring a load for power. The trickle charging method that stops charging and supplies electric power from the battery to the load only when There is a float charge in which the current necessary to make up the current flows. There is a limit to the current that can be passed through the battery during these charges, and there is what is called the allowable overcharge current. The magnitude of this current depends on the battery capacity of the sealed lead acid battery.
It is about 1/2000, and when it exceeds this size, the decrease of the electrolyte solution due to the electrolysis of water is accelerated and the battery life is shortened. Therefore, in normal charging, the current required to supplement the self-discharge is set below this current.

The positive electrode grid of a lead-acid battery is always in contact with an active material having a high electric potential, and is exposed to an oxidizing atmosphere, and at the same time, sulfuric acid having a strong corrosive property tends to be corroded at all times. is there. This tendency is that in a charged state, an overvoltage for charging is applied, so that the battery is placed in a stronger oxidizing atmosphere and corrosion is accelerated. The grid has a current collector function and a function of holding an active material, but when corrosion progresses, these functions tend to deteriorate and the battery life tends to be shortened.

In this way, it is necessary to constantly charge the battery.
It has the advantage of constantly supplying self-discharge of the battery and supplying the required power in an emergency, and at the same time has the disadvantage of promoting lattice corrosion and shortening the battery life, so these two can be well balanced to maximize the battery function. It's important.

[0005]

In the conventional trickle charging and float charging, charging is performed with an appropriate current that does not exceed the allowable overcharge current, but the battery is constantly charged with the charging voltage, so the charging time There was a problem that the corrosion of the positive electrode plate grid progressed in proportion to the above, and the battery life was shortened.

[0006]

According to the charging method of the present invention, in the use of a trickle or a float of a lead storage battery, instead of the conventional charging method of always charging, a charging time and a charging pause time are alternately repeated and a pause time is used. Charging is divided into two stages for self-discharging that increases by inserting the current, the first stage is charged with a current exceeding the allowable overcharge current, and the second stage is charged with a current less than the allowable overcharge current. The purpose is to extend the life of the battery by shortening the time for which the charging voltage is applied to the battery.

[0007]

【Example】

(Embodiment 1) A backup power system in which 56 sealed lead-acid batteries having a 2 V cell and a 10 HR capacity of 200 AH (allowable overcharge current is about 0.1 A) are connected in series, and the charging period is 30 in a period of 45 days. Day, charge rest period is 15 days, the first first-stage charge is constant current of 1.0A until the battery terminal voltage reaches 2.23V per cell, and then the remaining charge time is constant current of 0.05A. The second charge is performed by charging. After that, the battery was used in a charging method in which the charging was suspended for 15 days and the pattern was returned to the initial charging again. Comparing the decrease in battery capacity of the battery that has been subjected to this charging method for 7 years with the same type of battery used in the conventional charging method, the capacity decrease amount of the battery used by the charging method of the present invention is always 2 80 to 80% of the battery used in the conventional charging method of floating charging at .23V
It was as low as 85%. (Example 2) A standby power supply system in which 56 sealed lead-acid batteries having a 2V cell and a 10HR capacity of 200AH are connected in series,
In a cycle of 60 days, the battery is first charged with a constant current of 1.0A until the battery voltage reaches 2.23V per cell, then the remaining period is charged with a constant current of 0.05A, and then charged for 15 days. The battery was used in accordance with a charging method in which one cycle is a pattern in which a rest period is provided and the above charging is repeated. Comparing the decrease in capacity of a battery that has been subjected to this cycle for 5 years with a battery of the same type using the conventional charging method in which constant floating charging is performed at 2.23 V per cell
The decrease in capacity of the battery used by the charging method of this example was 85 to 90% of that of the battery used by the conventional charging method, which was small.

As can be seen from the results of the examples, the greater the proportion of the charging suspension period in the total use period, the smaller the decrease in battery performance.

[0009]

EFFECTS OF THE INVENTION In the intermittent trickle or intermittent float use, the life performance of the lead acid battery is improved by charging the self-discharge amount during rest without excess or deficiency and by efficiently performing the charging during charging.

Claims (1)

[Claims] 1. When using an intermittent trickle or an intermittent float in which floating charging and rest are alternately performed, floating charging is performed with a constant current of two stages, and the charging current of the first stage is set to a value exceeding an allowable overcharge current, and a charging voltage is set. When the charging voltage reaches the specified voltage, the second-stage charging is started, the charging current of the second step is kept below the allowable overcharge current, and the charging is stopped when the charging voltage reaches the specified voltage lower than the specified voltage of the first step. A method of charging a sealed lead-acid battery, characterized in that it has a rest period of 15 days or more.