Porsche 996 TT, Repair Manual

Page: 395 / 2099

top of page
Charging battery
WARNING
The battery plugs must always be screwed in correctly when charging and during the voltage measurement
and the load measurement.
Rooms in which batteries are being charged, should not be entered with a naked flame or when smoking.
Gases form through the charging process in the batteries which are highly flammable.
Note
A battery charging device is required. Gr. 3.9.1; Battery test charge device, Workshop Equipment
Manual. •
Observe charging device operating instructions.
•
The battery must have a minimum temperature of 10°C. •
Do not charge batteries too quickly if possible as they can be damaged in this way. •
If totally discharged batteries are charged quickly, they will not take up a charge current or they will
be indicated too early as being full by the so−called surface charge . •
1. Switch off battery charging device.
2. Switch ignition off and remove ignition key.
3. First disconnect the ground strap of the battery, then the positive battery
terminal.
4. Connect positive line of the battery charging device to the positive terminal of the
battery.
5. Connect negative line of the battery charging device to the negative terminal of the
battery.
6. Set the charge current on the battery of the charge device according to the battery capacity.
7. Switch on battery charging device.
Procedure for loading totally discharged batteries:
Batteries which are not in operation for a long period of time, discharge.
•
A battery is totally discharged if the open−circuit voltage has sunk below 11.6V. => Open−circuit
voltage measurement •
In totally discharged batteries, the battery acid (sulphuric acid water mixture) consists of virtually
only water, as the sulphuric acid proportion is considerably reduced. •
Totally discharged batteries sulphatise, i.e. the entire plate surface of the batteries harden.
•
If totally discharged batteries are immediately recharged after an exhaustive discharge, the
sulphatisation recedes again. •
If these batteries are not recharged, the plates continue to harden and charge take−up ability is limited.
A reduction in the battery performance is the result. •
Totally discharged batteries must be charged with a low charge current as follows:
•
einordnung
Battery load test 332