Mercedes-Benz Battery Maintenance, Starting,
and Charging Guidelines for SL-Class Vehicles
Topic number

LI54.10-P-077909

Version

1

Function group

54.10 - Battery, power supply, voltage converter

Date

5/31/24

Validity

R230

Reason for change

Complaint
Battery Control Module needs replacement due to electrical overstress.

Cause
Incorrect charging procedures and battery maintenance.

Remedy
Proper care and maintenance of the electrical system of MY2003-2012 SL-Class. Please share the below excerpts
from the Owner’s Manual and general guidance, cautions, and suggestions regarding battery charging and maintenance with customers.
Guidance and Cautions :
· Failure to follow these instructions can lead to severe injuries or death, damage to the vehicle or its electronic components, and/or cause a battery explosion.
· Following extended periods of non-operation, Mercedes-Benz AG (MBAG) recommends the use of Mercedes-Benzapproved battery chargers to ensure optimal battery maintenance and performance. Do not use a quick-charge unit
(“jump box”) and avoid jump starting after extended periods of non-operation. FOR DEALERS: For comprehensive
guidelines on battery charging, please refer to document AR54.10-P-1130I.
· Charge vehicle batteries according to the instructions in the owner’s Manual. Dealers can also reference WIS document AR54.10-P-1130I.
· If the battery needs to be removed, please follow the instructions in the owner’s manual and reinstall a new or charged battery in reverse order.
· MY2003-2012 SL-Class vehicles are equipped with two 12V batteries. See owner’s manual. If both batteries are
drained, never connect a charger to both batteries simultaneously.
Jump Starting:
· The starter battery is located on the right side of the engine compartment. Jump starting may only be performed on
the battery installed in the engine compartment. Never use the auxiliary battery installed in the trunk to jump start the
vehicle.
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· Do not attempt to start the engine using a battery quick-charge unit or battery charger/tender not approved by
MBAG.
· Only jump start from batteries with the same voltage rating (12V). Jump starting with a higher voltage battery could
damage the vehicle’s electrical system.
· Avoid repeated and/or lengthy starting attempts. This could result in damage to the vehicle or its electrical system,
severe injuries, or death.

Important Safety Notes (from Owner’s Manual):
· Never charge the battery while it is installed in the vehicle. Gases that can escape during charging may cause explosions and lead to paint damage, corrosion, and/or injuries.
· The starter battery is located on the right side of the engine compartment. Jump starting may only be performed on
the battery installed in the engine compartment. Never use the auxiliary battery installed in the trunk to jump start the
vehicle.
· Never lean over batteries while connecting or jump-starting. This could lead to injury and/or damage to the vehicle.
· Battery fluid contains sulfuric acid. Sulfuric acid is a corrosive substance that is destructive to the skin, eyes, teeth,
and lungs. Avoid contact with eyes, skin, or clothing. Immediately flush affected areas with water if contact occurs and
seek medical help if necessary.
· The battery also generates hydrogen gas, which is flammable and highly explosive. Keep flames or sparks away
from the battery, avoid incorrect connections of the jumper cables, smoking, etc.

For more detailed information, please refer to the owner’s manual.

Disclaimer
NOTE: The information contained in this document is intended for use by trained, professional technicians with the
knowledge to properly and safely perform diagnosis and repairs on Mercedes-Benz vehicles, using Mercedes-Benz
approved tools and equipment. It informs service technicians about conditions that could occur in certain vehicles and
provides information that could assist in proper vehicle diagnosis, service, or repair. It does not indicate that a defect
is present in any vehicle referenced in this document nor does it imply warranty coverage. DO NOT assume that a
symptom or condition, or a described cause of a symptom or condition, affects any particular vehicle or groups of vehicles, or that a described repair applies to any particular vehicle or groups of vehicles. There can be multiple causes
resulting in the same or similar symptoms or conditions described in this document, and trained professional service
technicians must use their diagnostic skills to make evaluations on a case-by-case basis. The information contained
in this document does not guarantee warranty coverage nor does it extend the vehicle’s warranty in any way.

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Symptoms
Overall vehicle > Power supply > Battery/On-board electrical system > Battery/on-board electrical system display
message > Charging

Operation numbers/damage codes
Op. no.

Operation text

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Time

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Damage
code

Note

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