Battery leakage test

A leak test on the battery is performed when frequent discharge is observed while it is unloaded and all other tests show that the battery is good. Dirt, moisture, and grease on the case can become conductive and cause the battery to leak. Over time, such leakage drains the battery. Batteries last longer if properly maintained.

When the battery is discharged with no load, a leakage test should be performed. A DC voltage digital multimeter is used for testing. Before measuring, it is necessary to disconnect and remove the battery from the vehicle. The black (minus) pipette of the multimeter is placed on the minus pole of the battery, and the red pipette is passed over the battery housing. Any measured voltage greater than 0.2 V indicates a leak. Clean the battery housing with a mixture of baking soda and water. Make sure that this mixture does not get inside the battery, because it will permanently neutralize the electrolyte and thus damage the battery. Grease is removed with a detergent solution or solvent. After cleaning, rinse the battery poles and terminals with clean water. Dry the components with a clean cloth or low-pressure compressed air. If a leak is detected on the cleaned battery even after the repeated test, the case has permanently lost its insulating properties and it is necessary to replace the battery with a new one.

To perform a battery leakage test, follow these steps:

Removing the battery from the vehicle

Before removing the battery terminal, check whether it is necessary to connect additional power for saving data in the memories of electronic devices. First, remove the minus terminal from the battery. Then remove the positive terminal. Release and carefully remove the battery from the base of the vehicle.

Leakage test

Set the DC voltage measurement on the digital multimeter. Place the black (minus) pipette on the minus pole of the battery. Move the red pipette over the battery housing. If you measure a voltage higher than 0.2 V stop the test because there is a leak.

Cleaning the battery case

If there is a leak, thoroughly wash the battery housing. Wash with a solution of baking soda and water. During washing, make sure that the solution does not get inside the battery. Remove greased parts with grease removers. After washing and drying, repeat the leakage test. If the leak is confirmed again, the case has permanently lost its insulating properties, is necessary to replace the battery with a new one.