The battery is one of the most expensive components of a Stromer. Stromer does not manufacture the batteries itself but has commissioned a Cooperation with the Taiwanese manufacturer HTE (TD Hitech Energy). At least the blue BQ983 model was also obtained from Simplon at short notice. The models can be distinguished by the screw connection of the front charging socket (Rosenberger bush).

In the course of model development, there has also been an evolution of battery models. There are two groups:
36 V batteries (8-cornered)
Originally there were 3 models:
BO322 violet | 11 Ah BO522 gold | 14.5 Ah
BO630 blue | 17.5 Ah (ST1 / V1 first gen.)
48 V batteries (square)
Originally there were 5 models:
BQ500 green | 10.5 Ah (Standard ST1)
BQ618 / 655 violet | 12.3 / 13.6 Ah (Standard ST2)
BQ814 gold | 15.9 Ah (Standard ST3)
BQ983 ST1 306AC / ST983 blue | 19.8 Ah / 20.4 Ah (standard ST5)
BQ1440 red | 28.5 Ah (ST7)
Compatibility
The batteries of the BO and BQ series are compatible in the respective series and can be exchanged. The exception is the BQ1440 battery, which only fits the ST7. BO and BQ batteries do not fit in the ST7. There is also no adapter.
Technical data for download
Status 2020

Status 2023

Battery data > Table
I have tried to explain the evolution and most important technical parameters of the batteries used by Stromer in a Table to unite. As Stromer, HTE and Simplon do not provide any detailed information themselves, this is based on research on the Internet.
Pin assignment
See ELEKTRIK & ELEKTRONIK - Cable diagrams | Pin assignment - 'Rosenberger - Plug connection'