battery replacement MERCEDES-BENZ R320 2008 W251 Owner's Manual

118 Controls in detail
Locking and unlocking
Checking the batteries in the SmartKey
or SmartKey with KEYLESS-GO*
Press button‹orŒ.
The battery check lamp (
page 110)
or (
page 113) comes on briefly to in-
dicate that the SmartKey or SmartKey
with KEYLESS-GO batteries are in
order.Loss of the SmartKey or SmartKey with
KEYLESS-GO*
If you lose your SmartKey or SmartKey
with KEYLESS-GO or mechanical key, you
should do the following:
Have the SmartKey or SmartKey with
KEYLESS-GO deactivated by an
authorized Mercedes-Benz Light
Truck Center.
Report the loss of the SmartKey or
SmartKey with KEYLESS-GO or the
mechanical key to your car insurance
company immediately.
Have the mechanical lock replaced if
necessary.
Any authorized Mercedes-Benz Light Truck
Center will be glad to supply you with a
replacement.
Opening the doors from the inside
You can open a locked door from the in-
side. Open door only when conditions are
safe to do so.
1Locking knob
2Inside door handle
iIf the battery check lamp does not come on
briefly during check, the SmartKey or SmartKey
with KEYLESS-GO batteries are discharged.
Replace the batteries (
page 479).
You can obtain the required batteries at any
authorized Mercedes-Benz Light Truck Center.
iIf the batteries are checked within signal
range of the vehicle, pressing the‹orŒ
button will lock or unlock the vehicle
accordingly.

479 Practical hints
Replacing SmartKey batteries
Replacing SmartKey batteries
If the batteries in the SmartKey or the
SmartKey with KEYLESS-GO* are
discharged, the vehicle can no longer be
locked or unlocked. It is recommended to
have the batteries replaced at an autho-
rized Mercedes-Benz Light Truck Center.
Batteries contain materials that can harm
the environment if disposed of improperly.
Recycling of batteries is the preferred
method of disposal. Many states require
sellers of batteries to accept old batteries
for recycling.Replacement batteries: Lithium, type
CR 2025 or equivalent.
Remove the mechanical key from the
SmartKey (
page 474).
1Mechanical key
2Battery compartment
Insert mechanical key 1 into opening.
Press mechanical key 1 in direction of
arrow.
The battery compartment is unlatched.
Pull battery compartment 2 out of the
SmartKey housing.
3Batteries
4Contact springs
Pull out batteries3.
Using a line-free cloth, insert new bat-
teries 3 under contact springs 4 with
the positive terminal (+) side facing up.
Return battery compartment 2 into
housing until it locks into place.
Slide mechanical key 1 back into
SmartKey.
Check the operation of the SmartKey
or SmartKey with KEYLESS-GO*.
Warning!G
Keep the batteries out of reach of children.
If a battery is swallowed, seek medical help
immediately.
iWhen inserting batteries, make sure they
are clean and free of lint.
iWhen replacing batteries, always replace
both batteries. The required replacement
batteries are available at any Mercedes-Benz
Light Truck Center.

504 Practical hints
Battery
!The battery is a valve-regulated lead acid
(VRLA) battery, also referred to as “fleece”
battery. Such batteries do not require topping-up
of the electrolyte level. VRLA batteries therefore
do not have cell caps and the battery cover is
non-removable. Do not attempt to open the
battery as otherwise the battery will be dam-
aged.
Even though VRLA batteries do not require
topping-up of the electrolyte level and cannot be
opened to check the electrolyte level, the
battery condition must be checked periodically
by performing a battery conductance test. Refer
to Maintenance Booklet for battery condition
testing intervals.
As with any other battery, the battery may
discharge if the vehicle is not operated for an
extended period of time. You can connect a
battery maintenance charge unit tested and
approved for use on your vehicle model or dis-
connected the battery to prevent battery dis-
charge. Contact an authorized Mercedes-Benz
Light Truck Center for more information.!The factory-equipped VRLA battery is
leak-proofed. Only use a battery as replacement
that has the same security features and is of
identical size, voltage, and capacity as the
factory-equipped battery.
The battery, the battery ventilation and the later-
al plug must always be securely installed when
the vehicle is in operation.
Warning!G
Jump starting must only be done using the
jump-start contacts located in the engine
compartment (
page 511).
Warning!G
Failure to follow these instructions can re-
sult in severe injury or death.
Observe all safety instructions and precau-
tions when handling automotive batteries
(
page 503).
Never lean over batteries while connecting,
you might get injured.
Battery fluid contains sulfuric acid. Do not
allow this fluid to come in contact with eyes,
skin or clothing. In case it does, immediately
flush affected area with water and seek
medical help if necessary.
A battery will also produce hydrogen gas,
which is flammable and explosive. Keep
flames or sparks away from battery, avoid
improper connection of jumper cables,
smoking etc.