Severely Discharged Batteries

Severely Discharged Batteries


Risk of injury. Observe warning notes and safety precautions. Refer to => [ Battery Safety Precautions ] Battery Safety Precautions and => [ Battery Safety Designation ] Battery Safety Designation!


Batteries that have a colorless or light yellow visual indicator do not have to be tested or charged. Jump starting must not be used!

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

These batteries must be replaced.


• Severely discharged batteries freeze earlier.

• Batteries that have frozen must no longer be used.

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

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

• Batteries which have not been used in driving operation for a long time, for example in stored vehicles, discharge themselves.

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

• Exhaustively discharged batteries become sulfated, i.e. all the plate surfaces of such batteries become hardened.

• The sulfating process may be largely 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 diminish. This results in reduction of battery performance.

- Check no load voltage. Refer to Midtronics => [ Battery, Testing ] Midtronics Battery Tester or VAS 6161=> [ Battery, Testing ] Battery Tester VAS 6161.