2019 MERCEDES-BENZ GLS SUV key battery

occupants from suffering acid burns should the
battery be damaged in the event of an accident.
In order for the battery to achieve the maximum possible service life, it must always be suffi-
ciently charged.
Like other batteries, the vehicle battery may
discharge over time if you do not use the vehicle. In this case, have the battery disconnected at a
qualified specialist workshop. However, you can also charge the battery with a charger recom-
mended by Mercedes-Benz. Contact a qualified
specialist workshop for further information.
Have the battery charge state checked more
frequently if you use the vehicle mainly for short trips or if you leave it standing idle for a lengthyperiod. Consult a qualified specialist workshop
if you wish to leave your vehicle parked for a long
period of time.
Remove the SmartKey if you park the vehicle
and do not require any electrical consumers.
The vehicle will then use very little energy, thus
conserving battery power.
If the power supply has been interrupted, e.g. if
you reconnect the battery, you will have to:
R set the clock (see the Digital Operator's Man-
ual)
On vehicles with a multimedia system and
navigation system, the clock is set automati-
cally.
R reset the function for automatically folding
the exterior mirrors in/out by folding the mir-
rors out once(Y page 111) Charging the 12 V battery
G
WARNING
During charging and jump-starting, explosive
gases can escape from the battery. There is a risk of an explosion.
Particularly avoid fire, open flames, creating
sparks and smoking. Ensure there is sufficient
ventilation while charging and jump-starting.
Do not lean over a battery. G
WARNING
Battery acid is caustic. There is a risk of injury. Avoid contact with skin, eyes or clothing. Do
not inhale any battery gases. Do not lean over
the battery. Keep children away from batter- ies. Wash away battery acid immediately with
plenty of clean water and seek medical atten-tion. G
WARNING
A discharged battery can freeze at tempera-
tures below freezing point. When jump-start-
ing the vehicle or charging the battery, gases can escape from the battery. There is a risk of
an explosion.
Allow the frozen battery to thaw out before
charging it or jump-starting.
! Only use battery chargers with a maximum
charging voltage of 14.8 V.
! Only charge the battery using the jump-
starting connection point.
The jump-starting connection point is in the
engine compartment (Y page 343).
X Open the hood.
X Connect the battery charger to the positive
terminal and ground point in the same order
as when connecting the donor battery in the
jump-starting procedure (Y page 343).
Keep away from fire and open flames. Do not
lean over a battery. Never charge the battery if it is still installed in the vehicle, unless you use a
battery charger which has been tested and
approved by Mercedes-Benz. A battery charger
unit specially adapted for Mercedes-Benz vehi-
cles and tested and approved by Mercedes-
Benz is available as an accessory. It permits the
charging of the battery in its installed position.
Contact an authorized Mercedes-Benz Center
for further information and availability. Read the battery charger's operating instructions before
charging the battery.
If, at low temperatures, the indicator lamps/
warning lamps in the instrument cluster do not
light up, it is highly likely that the discharged
battery has frozen. In this case you may neither
jump-start the vehicle nor charge the battery.
The service life of a thawed-out battery may be
shorter. The starting characteristics can be
impaired, particularly at low temperatures. Have
the thawed-out battery checked at a qualified
specialist workshop. 342
Battery (vehicle)Breakdown assistance

G
WARNING
A discharged battery can freeze at temperatures below freezing point. When jump-starting the
vehicle or charging the battery, gases can escape from the battery. There is a risk of an explosion.
Allow the frozen battery to thaw out before charging it or jump-starting.
! Vehicles with a gasoline engine:
avoid repeated and lengthy starting attempts. Otherwise, the
catalytic converter could be damaged by non-combusted fuel.
If the indicator/warning lamps do not light up at low temperatures, it is very likely that the dis-
charged battery has frozen. In this case you may neither jump-start the vehicle nor charge the
battery. The service life of a thawed-out battery may be shorter. The starting characteristics can be
impaired, particularly at low temperatures. Have the thawed-out battery checked at a qualified
specialist workshop.
Do not start the vehicle using a rapid charging device. If your vehicle's battery is discharged, the
engine can be jump-started from another vehicle or from a donor battery using jumper cables.
Observe the following points:
R The battery is not accessible in all vehicles. If the other vehicle's battery is not accessible, jump-
start the vehicle using a donor battery or a jump-starting device.
R Vehicles with a gasoline engine: only jump-start the vehicle when the engine and exhaust
system are cold.
R Do not start the engine if the battery is frozen. Let the battery thaw first.
R Only jump-start from batteries with a 12 V voltage rating.
R Only use jumper cables which have a sufficient cross-section and insulated terminal clamps.
R If the battery is fully discharged, leave the battery that is being used to jump-start connected for
a few minutes before attempting to start. This charges the battery slightly.
R Make sure that the two vehicles do not touch.
Make sure that:
R The jumper cables are not damaged.
R Bare parts of the terminal clamp do not come into contact with other metal parts while the jumper
cables are connected to the battery.
R The jumper cables cannot come into contact with parts that can move when the engine is running,
such as the V-belt pulley or the fan.
X Secure the vehicle by applying the electric parking brake.
X Shift the transmission to position 005D.
X Make sure that the ignition is switched off. All indicator lamps in the instrument cluster must be
off. When using the SmartKey, turn the SmartKey to position 0092in the ignition lock and remove it
(Y page 140).
X Switch off all electrical consumers, e.g. rear window defroster, lighting, etc.
X Open the hood.
i Right-hand-drive vehicle:
the jump-starting connection points may be located on the other
side of the vehicle. 344
Jump-startingBreakdown assistance

speed of 30 mph (50 km/h) must not be
exceeded.
For towing distances over 30 miles
(50 kilometers), the entire vehicle must be
raised and transported.
It is better to have the vehicle transported than
to have it towed away.
If the vehicle has suffered transmission damage, have it transported on a transporter or trailer.
The automatic transmission must be in position
005C when the vehicle is being towed.
The battery must be connected and charged.
Otherwise, you:
R cannot turn the SmartKey to position 0048in
the ignition lock
R cannot release the electric parking brake
R cannot shift the automatic transmission to
position 005C
Disarm the automatic locking feature before the vehicle is towed (Y page 241). You could other-
wise be locked out when pushing or towing the
vehicle. Permitted towing methods
Mercedes-Benz recommends transporting your
vehicle in the case of a breakdown, rather than
towing it away.
When towing away, use a towing rope or a tow-
ing bar with both axles on the ground. Do not use any tow bar systems. Installing/removing the towing eye
Installing the towing eye The brackets for the screw-in towing eye are
located in the bumpers. They are at the front and
rear behind covers 00430044.
X Remove the towing eye from the vehicle tool
kit (Y page 335).
X To open the cover at the front: press the
mark on cover 0043inwards in the direction of
the arrow.
X To open the cover at the rear: insert a flat,
blunt object into the cutout and lever
cover 0044out of the bumper.
X Take cover 0043or0044 off the opening.
X Screw in the towing eye clockwise as far as it
will go and tighten it.
Removing the towing eye X
Unscrew and remove the towing eye.
X Position cover 0043or0044 in the bumper and
press the cover on until it engages.
X Place the towing eye in the vehicle tool kit. Towing a vehicle with both axles on
the ground
The automatic transmission shifts to position
005D automatically when you open the driver's or
front-passenger door or when you remove the
SmartKey from the ignition lock. Towing and tow-starting
347Breakdown assistance Z