Stromer st1 Platinum battery issues or display issues?


New Member
I purchased this demo bike in Jan 2008. At first, when I had this bike I could not charge it up to 100%. I then called the dealer and they said it was the charger and they gave me a new one which seem to work at first. A few days ago I took out my Stormer for a ride with 74% still left on the battery but it quit on me about a mile away with the words in the display flashing "NO BATTERY". So I called the dealer again and while waiting for my new display to arrive I thought I would charge the battery up off the bike but when the charger turned off there was still a red light not green light and so I checked it with my multimeter and it now only shows only a total of 41.5 Volts....and no ticks on the battery in the display. So is it my display malfunctioning or do I have a bad battery or both? thanks for any input you can give me on this situation.

Roger R

New Member
This is a 36 volt battery, so when the multimeter shows 41.5 volt it means the battery should be close to fully charged. Usually the charger stops charging at 42 volts. As the battery get discharged the voltage will drop. When it reaches 30 volt the BMS will shut down the battery to save it from discharging too deeply.
That happened to my 2013 ST1 Platinum a few years back. I called Stromer support and was told there was a connector at the bottom of where the battery sits in the downtube that must of disconnected. If I remember correctly, I had to take the battery door off and then have my wife’s small hands reach down to the connector and reconnect it. She did, and I have never had that problem again.