Mercedes Benz 2009 M-Class User Manual

Page of 585
508
Practical hints
Battery
!
The battery is a valve-regulated lead acid 
(VRLA) battery, also referred to as “fleece” bat-
tery. 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 bat-
tery as otherwise the battery will be damaged.
Even though VRLA batteries do not require top-
ping-up of the electrolyte level and cannot be 
opened to check the electrolyte level, the bat-
tery condition must be checked periodically by 
performing a battery conductance test. Refer to 
Maintenance Booklet for battery condition test-
ing intervals.
As with any other battery, the battery may dis-
charge if the vehicle is not operated for an ex-
tended period of time. You can connect a battery 
maintenance charge unit tested and approved 
for use on your vehicle model or disconnect the 
battery to prevent battery discharge. 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 hose 
(
page 513) and the lateral plug (
page 513) 
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 515).
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 507).
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.