Battery, Checking Under Load Voltage
Battery
The battery is one of the most important electrical components in the vehicle. Its proper functioning is a major factor in ensuring customer satisfaction. To guarantee a long service life, the battery must be checked, serviced and maintained as described in this service information.
In addition to its function of starting the vehicle, the battery performs other tasks as a buffer and a source of electrical energy for the vehicle's entire electrical system.
Battery, Checking Under Load Voltage
Special tools, testers and auxiliary items required
• battery tester (VAS5097A)
• Using battery tester:
• => Operating manual
CAUTION!
Observe accident prevention procedures, wear protective clothing i.e. protective goggles and leather gloves.
Test Sequence
- Switch ignition off.
- Connect clips to the battery posts according to the instructions for the tester. The clips must make good contact with the battery posts.
- The load current will vary depending on battery capacity and must be set on tester accordingly. => Battery tester operating instructions
The load test currents can also be taken from the following table.
- Perform battery load test according to operating instructions and compare test result with table.
The load test determines the minimum voltage indicated according to battery capacity.
The load current and the minimum voltage vary depending on the battery capacity.
- If the minimum voltage is not reached, replace the battery.
Explanation for battery load test:
The strong load (resistance) during this test (a high current is flowing) reduces the battery voltage.
If the battery is in good condition, the voltage will only drop to the minimum voltage level.
If the battery is faulty or only faintly charged, the battery voltage will drop rapidly to below the displayed minimum voltage.
After the test has been performed, the voltage will remain at this low value for a long time, and voltage increases very slowly.