Open circuit voltage
Note.
- Necessary special devices, control and measuring instruments, as well as auxiliary means:
- Hand-held multimeter (eg "VAG 1526A").
Note.
- The battery must not be loaded with electrical consumers for at least 2 hours before the measurement.
- If the battery has been charged, the measurement should be taken no earlier than two hours after charging is complete.
1. Measure the battery voltage with a hand-held multimeter. The open-circuit voltage of the battery must not fall below 12.5 V. If the hand-held multimeter displays 12.5 V or higher, the battery voltage is normal.
2. If the hand-held multimeter displays a battery voltage value lower than 12.5 V:
Charge the battery.
After the battery has been charged and there has been at least 2 hours of waiting time, during which the battery must not be subjected to any electrical load or charged.
3. Measure the battery voltage with a hand-held multimeter. The open-circuit voltage of the battery must not fall below 12.5 V.
4. If the open circuit voltage of the battery is not normal, then the battery needs to be replaced.
Voltage under load
Note.
- Necessary special devices, control and measuring instruments, as well as auxiliary means:
- Battery testing device "VAS 5097A".
- Battery testing device "VAS 6161".
Attention.
- There is a risk of injury when handling batteries. Observe warnings and safety precautions.
- Batteries with a colorless or light yellow eye cannot be monitored or charged. These batteries must be replaced.
- Before using the instrument for testing, please read the instruction manual thoroughly and act accordingly during measurement.
Note.
- The battery temperature must be at least 10°C.
- If the battery has been charged, the measurement should be taken no earlier than 2 hours after charging is complete.
- For vehicles with the START-STOP system and the installed battery monitoring control unit "J367", the "-" terminal of the tester must be connected to the body ground. If connected to the negative terminal of the battery, the START-STOP system may malfunction after the measurement.
- When using the Battery Tester with the VAS 5097 A printer, there is no need to disconnect or remove the battery.
- The load current and minimum voltage vary depending on the battery capacity and are indicated on the label of the test device.
If the battery tester shows the following results:
- 1 - the starter power is sufficient
- 2 - starter power is poor
- 3 - starter power is very poor
- 4 - not verifiable (the device does not turn on, the LED does not light, does not print)
Explanations on battery load monitoring
Due to the high load on the battery during the inspection (a large current flows) the battery voltage drops.
If the battery is normal, the voltage value decreases to no more than the minimum voltage value.
If the battery is faulty or not sufficiently charged, the battery voltage will drop very quickly below the specified minimum value.
After checking faulty, discharged or low-charged batteries, this low battery voltage value remains for a very long time; the tension increases only very slowly.