Ampler Curt G1 refuses to start

[mefisto]

Hello,
My Ampler Curt G1 bike, after a long period of inactivity, wouldn't charge. Using a different charger, the battery charged, but the bike refuses to start. There's no response at all: no lights, no connection via the app, nothing. I suspect the controller. Has anyone on the forum encountered this problem?
My bike is a 2020 model.

 

[Greg Watts]

Hello, My Ampler Curt G1 bike, after a long period of inactivity, wouldn't charge. Using a different charger, the battery charged, but the bike refuses to start. There's no response at all: no lights, no connection via the app, nothing. I suspect the controller. Has anyone on the forum encountered t...

@mefisto - classic "long winter nap" scenario, and frustrating when the battery charges but the bike still sits there like a very expensive ornament. A few things to work through before assuming it's the controller:

First: the battery itself Just because it accepted a charge doesn't mean the BMS is happy. Lithium cells that have sat very low for an extended period can recover enough voltage to charge but still report unhealthy to the system. The bike's controller may simply be refusing to boot because the BMS is flagging a fault. If you can borrow another Ampler-compatible battery to test with, that'll tell you a lot quickly.

Second: connections before components As @Stihldog's post notes, a poor connection between battery and wiring harness can cause total power loss - no lights, no app, nothing. Clean the battery contacts with a dry cloth, check for corrosion (common after a long lay-up), and reseat the battery firmly a few times. It's a free first step and catches a surprising number of "dead bike" cases.

Third: controller Your instinct isn't wrong - the controller is a plausible culprit on a 2020 bike that's been dormant. But I'd want to rule out battery BMS state and connector issues first, because controllers are expensive and not always easy to source for a 2020 Ampler.

Practical next step: Contact Ampler support directly - from what I understand they're reasonably responsive and can sometimes pull diagnostic info or advise on whether the controller can be reset. A 2020 Curt G1 is likely out of warranty, but they may still be able to help with a reflash or point you to a compatible replacement.

Have you been able to test with a second battery at all?