One problem that has emerged in the forums is battery failure when using recuperation. The Stromer battery seems to have a problem at certain points with the relatively high currents that occur on steeper and longer downhill rides with a high recuperation level. Although the recuperation current is limited to 15 A, it exceeds the maximum permissible charging current of a single cell.
For example, the BQ983 battery (cell configuration 13S6P) contains Sanyo NCR 18650 GA cells are installed. This cell has a nominal charging current of 1.675 A. With a recuperation current of 15 A, 2.5 A is "pressed" into the cell per cell string (15 A / 6). This is therefore 50% above the recommended charging current.
The problem is exacerbated by cold temperatures or if the battery is older. I don't know what exactly is wrong with the batteries, but it is probably the BMS. As this is proprietary for the Stromer from HTE or Simplon, it cannot be freely purchased. The company upVolt in Basel is, as far as I know, the only company that does not repair but replaces BMS (Price). The BMS are not brand new but come from the recycling cycle of power batteries.
Stromer does not repair batteries, but replaces them with new ones.
See also AKKU - 'Repair / Refitting (Refit / Refurbishing) / Occasions'
If you want to conserve the battery, it is advisable to use recuperation levels 4 & 5 sparingly or not at all. The problem is also alleviated if an additional battery (extender) is used. Depending on the configuration, 10 or more cell strings are then connected in parallel, which reduces the recuperation current to below the nominal recommended charging current of the respective cells.
See also PIMP mySTROMER - 'Battery - Extender'
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