battery capacity PORSCHE 911 2009 5.G Owners Manual

Practical Tips, Emergency Service
263
Winter operation The capacity and ability of the battery to store
power decreases at low outside temperatures.
Moreover, the battery is more heavily loaded in
winter months, e.g. by the heated rear window,
more frequent use of additional lights, the fans
and the windshield wipers, etc.
fHave the battery checked before the start of
winter.
Maintenance note
Keep the battery well charged to prevent it
from freezing.
A discharged battery can freeze at 23 °F (--5 °C),
but a fully charged battery only freezes at -- 40 °F
(--40 °C).
A frozen battery must always be thawed before
connecting jump leads.
Replacing battery The service life of the battery is subject to normal
wear; it depends greatly on care, climatic condi-
tions, and driving conditions (distances, loads).
fOnly use an original Porsche battery, with the
correct part number, as a replacement.
fPlease observe the disposal instructions for
batteries.
Putting vehicle into operationAfter the battery is connected or after an exhaus-
tively discharged battery is charged, the multi-
functional PSM light lights up on the instrument
panel and a message appears on the on-board
computer to indicate a fault.
This fault can be remedied with a few simple
steps:
1. Start the engine.
2. With the vehicle stationary, perform a few
steering movements to the left and right and
then drive a short distance in a straight line
until the multifunctinal PSM light goes out and
the message on the on-board computer
disappears.
3. If the warnings do not disappear, then:
Drive carefully to the nearest authorized
Porsche dealer.
Have the fault remedied.
4. After the warnings disappear:
Stop the vehicle in a suitable place.
fPerform adaptation of the power windows:
Please see the chapter “STORING END
POSITION OF THE WINDOWS” on Page 26.

Practical Tips, Emergency Service
267
Emergency Starting with Jumper
Cables If the battery is discharged, e.g. in winter or after
the car has been parked for a long time, the bat-
tery of another car can be used for starting with
the help of jumper cables.
Make sure the voltage of both batteries is the
same. Both batteries must be 12 volt types.
The capacity (Ampere hours, Ah) of the booster
battery must not be substantially less than that of
the discharged battery.
The discharged battery must be correctly con-
nected to the vehicle’s electrical system.
fPlease see the chapter “BATTERY” on
Page 261.
fPlease see the chapter “EMERGENCY UNLO-
CKING OF THE LUGGAGE COMPARTMENT LID”
on Page 260.
Note
fDo not try to start the car by pushing or tow-
ing. Damage to the catalytic converters and
other components of the car may result.
Warning!
Risk of short circuit, damage and explosion,
resulting in serious personal injury or death.
fUse only jumper cables of adequate diameter
cross-section and fitted with completely insu-
lated alligator clips.
fFollow all warnings and instructions of the
jumper cable manufacturer.
fWhen connecting jumper cables, make sure
that they cannot get caught in any moving
parts in the engine compartment.
The jumper cables must be long enough so
that neither vehicles nor cables touch another.
fThe vehicles must not be in contact, otherwise
current might flow as soon as the positive ter-
minals are connected.
fThe cable clamps must not be allowed to con-
tact each other when one end of the jumper ca-
bles are connected to a battery.
fEnsure that tools or conductive jewelery (rings,
chains, watch straps) do not come into contact
with the positive jumper cable or the positive
battery post.
fImproper hook-up of jumper cables can ruin
the alternator. Danger of caustic burns from escaping acid.
fDo not lean over the battery.
Danger of gas explosion.
fImproper use of booster battery to start a
vehicle may cause an explosion, resulting in
serious personal injury or death.
fKeep sources of ignition away from the bat-
tery, e.g. open flame, burning cigarettes or
sparking due to cable contact or welding work.
fA discharged battery can freeze even at 23 °F/
–5 °C.
Before connecting jumper cables, a frozen
battery must be thawed out.