Porsche 911 Carrera Manual page 213

Battery care
f Ensure that battery is securely mounted.
f Keep terminals and connections clean and
properly tightened.
Corrosion can be prevented by coating the ter-
minals and connections with petroleum jelly or
silicone spray.
f Ensure that vent caps are securely tightened to
prevent spillage.
Checking the electrolyte fluid level
Generally, the electrolyte level must be checked
more often in summer than in the winter, and more
often when driving long distances.
f When adding water, use only clean containers.
In no case may alcohol (e.g. window cleaner
residues) be permitted to enter the battery.
f Unscrew and open the filler vent caps of each
cell.
With the car on a level surface, the fluid level
should meet the indicator mark in each cell.
f If necessary, top up with distilled water.
Do not use acid.
Only fill up to the mark, otherwise the electro-
lyte will overflow when the battery is being
charged and cause damage.
Battery charging
Automotive batteries loose their efficiency when
not in use.
The charge available in your battery can be meas-
ured with a battery hydrometer.
We recommend that the battery voltage be tested
by your Porsche dealer who has the appropriate
equipment.
If the car is not driven for prolonged periods, the
battery must be charged at least every 6 weeks.
A discharged battery allows rapid formation of sul-
fates, leading to premature deterioration of the
plates.
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Practical Tips, Emergency Service
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