Can BMS bypass increase the likelyhood of motor damage?

I have two boards based on Ownboard W2 and Wowgo 3X. Both boards use Hobbywing ESCs and both have rebuilt batteries with a BMS bypass for discharge (with a 40A fuse).

Right now each board has a busted motor. They are very twitchy / choppy when starting and accelerating. When testing boards upside down sometimes the motor gets stuck in a position where I have to give it a nudge or otherwise it won’t spin. I’m guessing the phases might be burnt out.

Both boards did have quite a lot of mileage before the battery rebuilds. Since then first board has made a few hundred kilometers before the motor failed but it’s a Mini board so I haven’t been pushing it that hard. The motor on the second died a maybe 100km after the rebuild.

So can a BMS bypass and burnt motors be related?

ur sensor connector either unplugged itself, or motor sensor are busted

shouldn’t be

I agree with @frame.b022, it sounds like a motor hall sensor problem

I tried testing a motor by spinning it with a drill and measuring voltages on phases. Good motor showed around 10V AC on all 3 phases. On the bad motor only phase showed 10V while two others were around 5.5 V

Motor sensors have nothing to do with the phase voltages, they are 5V and digital

Could you upload a pic of all the wires coming out of the motor?

I understand, I’m just saying that I tested phase wires and I think the problem might be in there, not in hall sensors, but I don’t have much experience here.

A moment ago I also run another test when the motor got stuck I checked for continuity between phases and it was only on one phase, the other two were dead. On the good motor it was 3 for 3. Then I played around some more with the bad motor, moved the the shaft and wires a bit and now the bad one is 3 for 3 as well on continuity, it’s working good for now. This has happened before.

As for wires, there are:
blue, yellow and green thick wires for phases
blue, yellow, green, black, red, white thin wires for hall sensors and other stuff. I’m guessing one might be a temp sensor or something.

Most likely hall, hall, hall, ground, 5V, temp, respectively

With the motor stopped, the phase wires should always have DC continuity between all phases. Any other result would seem to suggest a broken winding or termination or test device/connection.

Sounds like this may be the path to investigate more

I just rewired everything from the ESC up to almost the motor but not fully. I’m thinking maybe the issue is on that small length of wire I left sticking out of the motor.

I’m gonna look into that.


When you test the motor, make sure the ESC is disconnected from it

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Try a BLDC hand test

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