Charger making a fluttering sound... No power right after a brand new controller/motor.


New Member
Looking to pick your collaborative brains.

So I have about a 1 year old ST1 elite. Recently had the controller/motor replaced under warranty (they replaced the whole back wheel unit!) about a week ago. While riding home (and running low on battery) the bike suddenly cut out in the last 100 meters to home. Still had 10% charge left.

Got into the garage, tried to power up... No power up on the control unit. Plug the charger into the bike... Light is red and then there is suddenly a fluttering sound coming from the charger. It cuts out and repeats the sound again. I unplug immediately.

The battery will charge via the adapter outside the bike to green. However, even with the fully charged battery, the bike will not start. Again, when I try to charge through the bike... Red light, flutter sound from the charger.

The control unit and even the city kit will not light up.

Any advise, suggestions, or tricks would be helpful. I emailed the stromer dealer immediately. He has no idea what is going on.


Well-Known Member
I think The lcd module has a battery but I doubt it failed.

To me it sounds like a hard short.But it could be many things.

1Start with the simple.. try to re seat the battery in the bike cradle and apply a little pressure to the battery. See if it is just a loose connection.

2 PUt the battery in the bike, and disconnect the wires to the motor. They are quick disconnects, but you will need to cut some tye wraps to access them I think, so make sure you have some extra tye wraps. Turn on the power at the module and turn on the lights

3 Maybe You either have infant mortality of your new motor controller, OR whatever caused your first controller to fail caused the replacement to fail.
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Active Member
If possible keep your charging experiments outdoors. Till you have this issue resolved, and while St1 is in garage battery is removed. Charger sounds you describe sends up red flags to me.