smart EQ (453) range that drops suddenly or battery that will not charge, from a voltage difference between cells

Engine / equipment

smart fortwo and forfour EQ / electric drive (453)

Period mentioned

The whole electric 453 series

Symptoms

The range shown does not match the charge, drops very quickly after a short trip, or the high-voltage battery no longer charges. Possible codes: P0DE616 and P0DE717 (cell voltage too low or too high).

Possible cause described

The voltage difference between the highest and the lowest cell of the high-voltage battery is too large (over 100 mV) because a cell self-discharges; in extreme cases the battery management system no longer shows the cell voltages. It is described in Mercedes-Benz XENTRY technical note LI54.10-P-069138.

Check for the garage

Take it to the dealer soon: they read the cell voltages with the diagnostic equipment and assess whether it can be transported (the self-discharge gets worse with time). The fix the brand gives is replacing the high-voltage battery. Never handle the high-voltage system.

Cost cited in the source

No verified estimate; ask the garage for a quote.A rough figure from the original database, not an up-to-date quote.

Sources from the original database