Measuring the No Load Voltage

Measuring the No Load Voltage

• Measuring the no-load voltage, for example, during the prescribed maintenance and service work on vehicles in storage, determines whether the battery must be recharged.

Special tools, testers and auxiliary items required

• Handheld Multi-Meter (V.A.G 1526D)

Procedure

To ensure a correct measurement, the following points must be followed.

• Battery must not be loaded by electrical consumers within the next 2 hours before measurement.

• After battery charging or engine operation, the measurement can be performed only after a 12 hour waiting period.

• The battery temperature must be at least 10 °C (50 °F).

After a waiting period of at least 12 hours:

- Measure the voltage between the battery terminal clamps.

• Specified value: 12.5 volts or higher, the battery is OK.

- If the no load voltage is under 12.5 volts, the battery must be recharged. Refer to => [ Battery Charger, Charging the Battery ] Battery Charger, Charging the Battery.

- After charging for 5 minutes, the current draw must be measured again. Refer to => [ Battery Test via Current Draw ] Battery Test via Current Draw.

- If the battery no load voltage is 11.6 volts or lower, the battery is exhaustively discharged.