Totally Discharged Batteries, Charging

Totally Discharged Batteries, Charging

• Batteries which have not been used for lengthy periods, e.g. in vehicles which have not been driven, are subject to self-discharge.

• Batteries are considered to be severely discharged if open-circuit voltage drops below 11.6 V. With voltage between 12.2 and 11.6 V, the battery is pre-damaged. Measure no-load voltage:

• Vehicles without Energy Management Control Module ( J644) => [ Battery No-Load Voltage - Vehicles without Energy Management Control Module, Checking ] Battery Testing.

• Vehicles with Energy Management Control Module ( J644) => [ Battery No-Load Voltage - Vehicles with Energy Management Control Module, Checking ] Battery Testing.

• With severely discharged batteries, the electrolyte (mixture of sulfuric acid and water) is mostly water, with a greatly reduced sulfuric acid content.

• Severely discharged batteries become sulfated, i.e. all the plate surfaces of such batteries become hardened. Instead of being transparent, the electrolyte has a slightly milky appearance.

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

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

CAUTION!
Risk of injury from battery acid.

• Prior to handling or servicing batteries, read, understand and observe the Warnings and Safety Measures for lead-acid batteries for lead-acid batteries => [ Safety Precautions ] Battery!

• Wear protective eyewear and clothing => [ Protect against injury by using protective
eyewear and clothing. ] Battery.

• On non-maintenance-free batteries, the sealing plugs must be installed tightly.

• Provide sufficient ventilation.

• If the magic eye has no color or is light yellow, the battery may not be tested or charged. Jump starting must not be used! There is a risk of explosion during testing, charging or jump starting. The battery must be replaced.

• DO NOT battery test batteries which are gassing. Otherwise there is a risk of explosion.

• Rapid-charging batteries => [ Battery, Quick Charging ].

• Dispose of electrolyte (sulfuric acid/water mixture) properly! Waste electrolyte must only be disposed of in appropriate waste disposal sites. Refer to local regulations pertaining to electrolyte disposal.

• The following notes and procedures must be followed to ensure correct charging.

CAUTION!
Risk of severely discharged batteries freezing.

• Severely discharged batteries freeze at low temperatures, the housing can crack.

• Batteries that have frozen must no longer be used.

Prerequisite

• Battery temperature must be at least +10 °C.

Procedure

Severely discharged (sulfated) batteries must be charged using a low charging current:

• The Midtronics Diagnostic Conductance Charging Station (INC-940) automatically detects severely discharged batteries and carefully starts the charging procedure with a low charging current. The charge current is automatically adjusted to the battery charge state.

• In order to initiate charging procedure, battery voltage must be at least 0.6 V!

CAUTION!
Risk of damaging severely discharged batteries.

• Do not quick charge severely discharged batteries.

- Charge battery => [ Battery, Charging with Midtronics Diagnostic Conductance Charging Station INC-940 ].

• The charging voltage may be a maximum of 14.4 V.

• If battery is replaced, follow disposal regulations => [ Personal injury and environmental risk. ] Battery.