Severely Discharged Batteries

Severely Discharged Batteries


Risk of injury. Observe the warnings and safety precautions => [ Dangers When Working with Batteries ] Dangers When Working with Batteries!

For a battery to be designated as severely discharged, the resting voltage must be less than 11.6 V.


Do not check or charge a battery when the visual indicator has no color or is bright yellow. Jump starting must not be used!

There is a risk of explosion during testing, charging or jump starting.

The battery must be replaced.


• Severely discharged batteries freeze earlier.

• Batteries that have frozen must no longer be used.

• Batteries, which have not been used for a long time, will discharge by themselves.

• In severely discharged batteries, the electrolyte consists almost completely of water, because the acid portion has been greatly reduced.

• Severely discharged batteries become sulfated, meaning all of the plate surfaces harden.

• The sulfation process may be reversed if a severely discharged battery is recharged immediately.

• If the battery is not recharged, the plates will continue to harden, and the ability to accept a charge will decrease. This results in reduction of battery performance.

• Severely discharged batteries in vehicles must be replaced prior to delivery. Pre-existing damage cannot be ruled out.

- Check battery no load voltage, refer to => [ Battery, Charging ] Battery, Charging.

- Charge the battery.

• Charge the battery with the Battery Charger (VAS 5903). Refer to => [ Severely Discharged Battery, Charging ] Severely Discharged Battery, Charging.

• Charge the battery using the Midtronics (INC 940). Refer to => [ Battery, Charging ] Battery, Charging.