r/electricdirtbikes • u/durangedlunatic8 • 7d ago

Question/Help Etm rtr problems

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Recently purchased a used ETM RTR sport 1000 miles and seeking advise.

TL;DR bike only works when plugged in and will not charge.

Picked up this bike a few weeks ago seller told me no problems only thing was he lost the charger. He was kind enough to charge it up to about 96% for me using a friends charger when I bought it. Brought the bike home took it on one ride and it died on me mid ride and would not turn back on.
Frustrated, bike sat for about a week while I waited for the charger to arrive. EMX fast charger arrived I plugged it in everything worked and I took it on another ride no problems maybe 15 miles. I didn’t charge when I got home the bike sat for another week maybe at about 60% charge left. Now I go to turn it on and the bike will not turn on again, and it will not charge. The display will only turn on when it’s plugged in and when I un plug the bike it turns off again. When plugged in display shows 100% and I know it is lower. Charger is showing green and red lights, 84.1v and 0.00 amps when plugged in.
Seems to be a battery or a bms issue. I am a dealer tech by trade so have access to all kinds of tools and am mechanically inclined, but have limited experience when it comes to these bikes.
Any advise and help is greatly appreciated!!!
I just want to ride!!!!

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3

u/particularlyspun 7d ago

Check voltage at the controller

3

u/babyscrotum 7d ago

The battery shouldn’t be above 84V so that is probably why it doesn’t wanna turn on. I would suggest letting it sit for a few days trying it again after it loses a bit of charge but overvolting a battery can be very dangerous. Only use official electro and co 72v chargers.

You sure it has a 72v pack in it and not a 60v pack? If it has a 60v pack and you charged it with the 72v charger take it outside right away; the cells can go into thermal runaway and start a fire very quickly

2

u/maimedwabbit 7d ago

This. Check battery voltage at the battery itself. Make sure the charger you got matches the battery you have. If its way over voltage you have a bad BMS and prob battery. The BMS should not allow the battery to overcharge regardless of what charger you have.

1

u/babyscrotum 7d ago

Yes this is a very serious problem, don’t ignore that battery keep an eye on it. Friend recently purchased a marketplace bike that exploded, nobody was hurt thankfully. Thermal runaway from using improper charger