Porsche Boxster 2006 Owner's Manual page 251

Winter driving
The capacity and ability of the battery to store
power decreases at low outside temperatures.
Moreover, the battery is more heavily loaded in the
winter months, e.g. by the heated rear window,
the more frequent use of additional lights, the
blower and the windshield wipers, etc.
f Have the battery checked before winter
begins.
Keep the battery well charged to prevent it from
freezing.
A discharged battery can freeze even at
23°F/-5 ° C, but a fully charged one only freezes at
-40°F/-40 °C.
Laying up the vehicle
If the vehicle stands for long periods in the garage
or workshop, the doors and lids should be closed.
f Please observe the chapter "EMERGENCY
UNLOCKING OF THE FRONT LUGGAGE
COMPARTMENT LID" on Page 248.
f Withdraw the ignition key and, if necessary,
disconnect the battery.
When the battery is disconnected, the
alarm system ceases to function!
Even if you put your vehicle out of operation, the
battery still discharges.
f The battery must be charged, i.e. connected
to a charger, approximately every 6 weeks in
order to preserve functioning.
Always observe the instructions of the charger
manufacturer.
f Store a battery that has been removed in a
dark, cool place, but not subject to frost.
Replacing the battery
The battery is subject to normal wear: its service
life depends heavily on the care you give it,
climatic conditions and the conditions of use
(distances, loads).
It is not possible to use the details on the battery
case to determine a comparable battery that
meets all the specific requirements of Porsche.
f Use only a battery that meets the specific
requirements of your vehicle as a replacement.
We recommend that you use an Orignal
Porsche battery.
f Please observe the disposal instructions for
batteries!
Practical Tips, Emergency Service
251