How to repair the maintenance-free battery?

Date:Aug 30, 2019

1, Clean up

Before maintaining the battery, first clean the dust on the surface of the battery being repaired, and remove the stain and rust on the terminal.

2. Open the exhaust valve and observe the electrolyte inside the battery.

Pry open the glued or heat-sealed battery cover to expose the rubber exhaust valve of the maintenance-free battery. Carefully remove the exhaust valve and store it. Observe the internal condition of the battery. Add 0.1% to 0.5% of the electrolyte to the battery, and there is just a flowing electrolyte on the battery. At the same time, check whether it is made of black impurities. If there are obvious black turbid impurities, the positive plate of the battery has been obviously softened, and the possibility of battery repair is relatively small. If there is no black turbidity, wait for 4 hours and the water is well deep into the battery. If the battery capacity is reduced only because the deactivation time is long, and this step is not required, you should go directly to step 3 for pre-charging.

3, Pre-charge

Constant voltage current limiting charging of the battery. At the beginning, it is charged with a current of 0.1C to 0.25C. After 16.2V, the charging voltage is maintained by reducing the current until the charging current drops to 0.03C. Note that when charging, there will be gas carrying electrolyte from the vent hole. In order not to pollute the environment, the battery should be placed in a specific container. After charging, observe whether there are free molecules inside the battery. If not, you need to make up 0.1% of the solution until a few free molecules appear. If there are free molecules in each cell, use the pour and pipette to aspirate the visible free molecules to keep the battery in a quasi-lean state. After the end of charging, after the battery is still for half an hour, measure the open circuit voltage of the battery. The voltage should be above 12V. If the battery voltage is lower than 12V, especially below 10.8V, the battery may have an internal short circuit. The battery has no maintenance value.

4, Repair

Connect the positive and negative outputs of the repairer to the positive and negative poles of the battery, turn on the repairer, and repair the battery. The first repair time should be no less than 48 hours.

5, Capacity test

The battery was discharged at a current of 0.1 C, and the discharge time was recorded. The discharge current multiplied by the number of hours is the capacity of the battery repair. If the Chongqing battery capacity reaches more than 70% of the nominal capacity, the repair is terminated. If the capacity does not reach 70% of the nominal capacity, continue to charge according to step 3. After the charging, the repair is continued. Generally, the battery that has been stored for a period of one year needs to be repaired twice before it can be restored to the state before the overdue storage.

Previous: Lead-acid battery charging and discharging working principle

Next: Seven points of battery safety precautions