Mercedes-Benz 2002 SLK 230 Kompressor Operator's Manual page 224

Therefore, we strongly recommend that you have the
battery charge checked frequently, and corrected if
necessary, especially if you use the vehicle less than
approximately 200 miles (300 km) per month,
mostly for short distance trips, or if it is not used for
long periods of time.
Only charge a battery with a battery charger after the
battery has been disconnected from the vehicle's
electrical circuit.
Always disconnect the battery negative lead first and
connect last.
When removing and connecting the battery, always
make sure that all electrical consumers are off and the
key is in steering lock position 0. The battery must
always be securely installed when the vehicle is in
operation. During removal and installation always
protect the disconnected battery positive (+) terminal
with the cover attached to the battery.
While the engine is running the battery terminal clamps
must not be loosened or detached, otherwise the
generator and other electronic components will be
damaged.
Battery
Instruments
Operation
and controls
221
Instrument
Driving
cluster display
Battery recycling
Batteries contain materials that can harm the
environment with improper disposal.
Large 12 Volt storage batteries contain lead.
Recycling of batteries is the preferred method of
disposal.
Many states require sellers of batteries to accept old
batteries for recycling.
Practical hints Car care
Technical
Index
data