Disconnecting Starter Battery - Mercedes-Benz S 450 4MATIC Operator's Manual

Do not rub the battery with rags or cloths.
The battery could explode if touched due to
electrostatic charge or due to spark forma-
tion.
!
Switch off the engine and switch off the ve-
hicle's internal electrical functions ( page 732)
before you disconnect or remove the battery's
terminal clamps. You could otherwise destroy
electronic assemblies such as the generator.
Have the battery checked regularly by an autho-
rized Mercedes-Benz Center. Refer to Mainte-
nance Booklet for maintenance intervals or
contact an authorized Mercedes-Benz Center for
further information.
!
Do not connect any consumers directly to
the starter battery. The starter battery will other-
wise be discharged.
i
Only replace a discharged battery with a bat-
tery recommended by Mercedes-Benz. The con-
sumer battery is installed in the trunk in such a
way that it is safeguarded as much as possible
against mechanical destruction in the event of
an accident.
i
Remove SmartKey from starter switch (vehi-
cles with KEYLESS-GO*: Make sure the vehicle's
on-board electronics have status 0)
( page 370) when you turn off the engine and
no longer require any electrical consumers. The
vehicle then uses very little power and the con-
sumer battery is spared.
Starter battery (example illustration from
S 550)
1 Negative terminal
2 Positive terminal
i
If the consumer battery is discharged, you
must use the mechanical key to unlock the vehi-
cle ( page 708). Since the vehicle has a sepa-
rate starter battery, however, you can still start
the vehicle.
Practical hints
Batteries

Disconnecting starter battery

!
Always disconnect the starter battery in the
order described below. You could otherwise
damage the vehicle's electronics.
!
Switch off the vehicle's internal electrical
functions before disconnecting the starter bat-
tery. If the vehicle is stationary for more than one
hour with the SmartKey removed, you do not
need to switch off the vehicle's internal electrical
functions.
Secure vehicle in place with electronic
parking brake ( page 422).
Shift the automatic transmission to
park position P ( page 426).
731