engine AUDI A4 1998 B5 / 1.G Battery Workshop Manual

27-1


Battery
The battery is one of the most important
electrical components in the vehicle. If it
functions properly, the battery will make a
significant contribution to customer satisfaction.
To ensure a long service life, the battery must be
checked, serviced and maintained as described
in this section.
In addition to starting the engine, the battery has
additional functions as a buffer and supplier of
electrical power for the entire vehicle electrical
system.
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Electrolyte level too high

Special tools, test equipment and auxiliary
items

Commercially available hydrometer
Note:
If the electrolyte level is too high, the sulfuric acid/water mixture will leak
to the outside of the battery and damage functional components in the
engine compartment.
- If electrolyte level is too high (overfilling), i.e., it is above internal
electrolyte level mark (lip of plastic flange) or external maximum line,
draw off excess electrolyte using commercially available hydrometer.
- Draw off electrolyte using hydrometer until electrolyte level has
reached lip of plastic flange or maximum line.
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Load test results

The severe load (ohmic resistance) during this
test (high current draw) causes the battery
voltage to drop. If the battery is in good
condition, the voltage value will only drop to the
minimum voltage. The minimum voltage varies
and depends on battery capacity and cold
cranking amps. Cold cranking amps is
understood to be the capacity of the battery in
cold weather. Batteries with high cold cranking
amps are especially important in vehicles with
high compression engines.
If the battery is faulty or has only a weak
charge, the battery voltage will drop off very
quickly "voltage collapse" (voltage below 9.0 V).
After the test is completed, this low voltage will
last for a longer period of time and the voltage
will increase only very slowly. Such a battery
will no longer reach a usable voltage (no-load
voltage) Page 27
-12
.

A battery with the faults described above does
not have the power reserve of an undamaged
battery and must be discarded.
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