Repair / Refitting (Refit / Refurbishing) / Occasions

Repair

A repair must be distinguished from a reassembly. In a reassembly, the cells in the battery are replaced with new ones. The term repair refers to the replacement of individual, defective cells, the repair of the BMS or the housing, e.g. the Rosenberger charging socket.

The following work is possible with the BO / BQ series batteries:

• Replacement of individual, defective cells: NO
• BMS repair: NO **
• BMS exchange: YES **
• Reset SoH and charge cycle counter: YES **
• Replacement charging socket: YES;
  See PROBLEMS - BATTERY - 'Battery charging socket defective'
• Reset the battery: YES (by myStromer AG)
  See AKKU - 'Battery reset'

Stromer does not repair batteries. However, if the battery goes into the safety position due to a problem in the Stromer electrical system, Stromer can reset the battery.

Refitting (Refit / Refurbishing)

Stromer batteries are not cheap. Relevant companies have recognized a market here and offer the assembly with new cells. This is not a problem with the BO series batteries, but it is with the BQ series (square) from around 2016. Physically replacing the cells is not the problem. The only thing to check is that high-quality Li-ion and not cheap Cinaware is used.

The sticking point with the BQ batteries is the BMS. Not only is it relatively energy-hungry in standby mode, it is also necessary to reset the SoH and charge cycle counter to the factory settings. If this is not done, only the old, reduced range can be used despite the new cells.

** Refurbisher - Table

In the Table I have listed a few suppliers who offer cell renewal. As of July 2025, however, I am only aware of three companies (highlighted in green) that can reset the charge cycle counter and SoH value to factory settings. Another restriction is that the BQ814 and BQ983 battery was/is manufactured by two suppliers, HTE and Simplon. A reset is only possible with the HTE model, the model with three screws. Simplon batteries have four.

Summary

Many messages in forums indicate that a reconditioned battery does not function as desired. The new range is not achieved.

A refurbisher must have the software for the BQ819 & BQ983 batteries (approx. from 2016) to reset the Stromer BMS (SoH= 100% / charge cycles= 0). The battery does not need to be opened. The reset takes place via the CAN bus and is only possible on models with 3 screws.

For the 36 V batteries (BO series) and the older BQ series (48 V, blue, yellow, purple, green before 2016), there are indications that an SoH reset is not necessary and that the new range can be driven after a cell replacement.

TipHave the reconditioner/refurbisher confirm that the original range has been reached or that the SoH and charge cycle counter can be reset.

Occasions

On the myStromer website haendler0/flagship-store you can find bikes and sometimes batteries at reduced prices under "second-hand sales". Second-hand batteries can always be found on various advertising portals (Ricardo.ch, ebay, Kleinanzeigen.de...).