With the ST1, ST2-Belt, and ST7 models, Stromer has placed the controller and distribution board „in the frame,“ likely also with the intention of better protecting them from moisture there. Direct spray from the front wheel cannot reach the controller and distribution board within the frame.
However, depending on the temperature difference between the battery/battery compartment and the outside air, condensation can form in the compartment in winter. As the board was not originally protected against moisture, corrosion can occur.
If the corrosion has not progressed too far, it can be removed with isopropyl alcohol and a fiberglass brush. Afterwards, protect the pins on the back and front with a Silicone protective varnish. The connectors and plug pins are treated with a little Electrolube.
Stromer has since made improvements and newer years of the distribution board are better protected against moisture.
Here is the fully encapsulated version in the ST7 of more recent batches.
