Porsche 911 Carrera Manual page 214

Warning!
Hydrogen gas generated by the battery
could cause an explosion, resulting in severe
personal injuries.
f Charge battery in a well ventilated area.
f Never charge a frozen battery. It may explode
because of gas trapped in the ice. Allow a fro-
zen battery to thaw out first.
f 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 doc-
tor.
214
Practical Tips, Emergency Service
Slow battery charging
1. Pay attention to all warnings and follow instruc-
tions that come with your battery charger.
2. When charging, ensure adequate ventilation.
3. Remove battery.
Please observe the chapter "REMOVING THE
BATTERY" on Page 216.
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 POSITIVE (+) 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 217.
Winter operation
The capacity and ability of the battery to store
power decreases at low outside temperatures.
Additionally, more power is consumed while start-
ing, and the headlights, heater, rear window de-
fogger, etc., are used more frequently.
f Let your Porsche dealer test the battery's
capacity before winter sets in.
The battery will discharge more quickly if your ve-
hicle is not driven on a daily basis over a distance
of several miles. The more often you drive your ve-
hicle, and the longer the distance driven on each
trip, the more opportunity the vehicle's charging
system will have to recharge the batteries.