Occasionally, the battery in the bike does not charge.
Reason 1
Contact problems between the battery and the Rosenberger charging socket in the battery compartment or the charging socket of the Stromer. This is caused by corrosion, the use of contact sprays/grease or small metal particles.

Reason 2
The 'Charching Section' on the controller is defective.

The only solution here is to replace the controller. A repair is not possible.
Handling - Inserting the battery
The following procedure can help to ensure that the battery is positioned correctly in the battery compartment.
Slide the battery down the battery compartment cover. Press the flap closed a little, the battery will slide about 1 cm down into the Rosenberger charging socket. Then fold the battery retaining clip into the groove at the top of the battery compartment cover and close the battery compartment with a little swing.
> See also PROBLEMS - AKKU - 'Battery not charging - deep discharged?
> See also ERRORS - AND WARNINGS - 'E 21041C' - Battery does not charge'