Porsche 911 Carrera - Manual (Page 298)

Battery care
Ensure that battery is securely mounted.
Keep terminals and connections clean
and properly tightened. Corrosion can be
prevented by coating the terminals and
connections with petroleum jelly or silicone
spray.
Ensure that vent caps are securely tightened
to prevent spillage.
Checking the electrolyte uid level
Generally, the electrolyte level must be checked
more often in summer than in the winter, and more
often when driving long distances.
When adding water, use only clean containers.
In no case may alcohol (e.g. window cleaner
residues) be permitted to enter the battery.
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.
If necessary, top up with distilled water.
Do not use acid. Only fill up to the mark,
otherwise the electrolyte 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 measured 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
sulfates, leading to premature deterioration of the
plates.
Danger!
Hydrogen gas generated by the battery
could cause an explosion, resulting in serious
personal injury or death.
Charge battery in a well ventilated area.
Never charge a frozen battery. It may explode
because of gas trapped in the ice. Allow a
frozen battery to thaw out first.
If you get electrolyte, which is an acid, in your
eyes or on your skin, immediately rinse with
cold water for several minutes and call a
doctor.
Slow battery charging
1. Pay attention to all warnings and follow
instructions that come with your battery
charger.
2. When charging, ensure adequate ventilation.
3. Remove battery.
Please observe the chapter ”REMOVING THE
BATTERY” on page 297.
4. All vent caps should be open. The fluid level
should meet the indicator mark in each cell.
5. Ensure that charger is switched off - danger of
short circuit!
6. Connect charger cables. Charger cables
must be connected POSITIVE (+) to POSI-
TIVE (+) and NEGATIVE (-) to NEGATIVE (-).
7. Switch on charger. Normally, a battery should
be charged at no more than 10 percent of its
rated capacity. Rated capacity of the battery in
your vehicle is listed on the battery housing.
8. After charging, turn off charger and disconnect
charger cables.
9. Tighten the vent caps and reinstall battery.
Please observe the chapter ”INSTALLING THE
BATTERY” on page 298.
Winter operation
The capacity and ability of the battery to store
power decreases at low outside temperatures.
296
Practical Tips, Emergency Service