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Replacing the Backup Battery on Mercedes Class B W246

Model: Mercedes Classe B W246, MK 2 - Years 2011-2019
Part: Battery

If the display on the instrument panel shows "backup battery fault," it may indicate either a real depletion of the backup battery or, on some models with start&stop devices, a fault in the capacitor located behind the handbrake, which should assist in starting when the main battery begins to deplete. In the case of the Class B W246, this battery is located in the passenger compartment, on the passenger side, directly under the mat, beneath the carpet lining in the heel area, practically under the glove compartment.

Updated on 1 March 2026 by ScegliAuto

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