Two Stromers, two problems

Chris Marks

New Member
I was recently gifted a pair of Stromer ST1s (I know, very fortunate), one white and one black. White one has 54 miles, black one has 170. Both were sitting for a long time, main batteries (522wh) AND the controller batteries were both dead. I replaced the batteries in the controllers and plugged both in to their chargers.

The white battery was completely dead and wasn't even registering on the controller. It would not (and will not) charge when the charger is plugged into the bike. When I pulled the battery out and plugged it directly in it charged to 100%. Bike rides perfect (why wouldn't it, it's new) but won't charge when the battery is in the bike.

The black bike's battery registered and started charging right away but it only charges up to 4 bars. No matter how much I ride it and recharge it, it only charges to 4 bars. BUT........when I put that battery in the white bike it registers 100%. So I'm guessing it's a meter issue? I definitely get good mileage out of the black bike, 20+ miles with 2 bars left.

So problems are:
1. White bike isn't charging the battery (but the battery WILL charge when directly connected)
2. Black bike's battery meter is miscalibrated

Anything I can do to fix these problems on my own? I'm very handy, not afraid to dig in if it's something I can manage without breaking something else :)

Thanks in advance!


Active Member
Bump for battery problems!
Not sure there is an easy fix here? It almost sounds as though there might be a problem either with the adapter to plug in the ST-1 or the receiver for the battery connection on the white bike...pure conjecture upon my guesses on the black bike; best of luck solving the problem and enjoy the bikes.


Well-Known Member
On a good battery I get 20 plus on power. Good chance you have at least 1 bad battery. A good replacement might be able to verify the others shape. Where are you? To verify batteries do not charge In the bike. If the bike has an issue it could effect charging. The meter issue could be a BMS issue that may be only fixed by replacing the battery so living with the "meter" issue may be the cheapest way to deal with. Find a Stromer dealer or person that has a working Stromer of your model. I believe the shop in Vegas can rebuild your dead battery but I think they use the old BMS so the meter issue battery may not be a candidate.

I had 1 battery that would show 0 and build to 100 after about 1-2 minutes on either Stromer, worked fine but the first couple of times had me worried I was stranded like 30 miles from home. It became the battery I used 1st :)

russ moir

I'd swap controllers using the good battery, and see if the battery display issue goes with the bike or controller. I've had a bad controller myself.

Re charging issue - using the same charger? with the non-charging bike and charging the battery directly?
Looks if the battery runs the bike, its less likely the issue is with the battery socket - more likely an issue with the charging port or wiring attached to it.

If you have 2 chargers, then you need to first test to see if both fail to charge the problem bike .. ie its the socket/internal wiring