I have a 24 vdc brushed motor (~750 watt) driven by a LiFePO4 battery pack with a BCM. My problem is that when I put a load on the motor, it will run for less than a minute and then stop. Below is a plot of the voltage and amperage while under load. As you can see, the pack voltage stays around 25 vdc while the motor draws between 4 and 8 amps. I have a PWM speed controller on this motor, but the problem existed before I put the speed controller on it. You can see me changing speed in the first 3 steps and then stopping and starting the motor around .8 min. After less than a minute, I get this huge current spike (49 amps) and this causes the BCM to trigger the 40 amp cut-off.
I'm inclined to think the problem is with the motor, not the pack or BCM. What would cause this kind of behavior? I've cleaned the commutator and the brushes are new. Seems like some sort of thermal event is causing a short or something. Anyway, I'm looking for ideas!
I'm inclined to think the problem is with the motor, not the pack or BCM. What would cause this kind of behavior? I've cleaned the commutator and the brushes are new. Seems like some sort of thermal event is causing a short or something. Anyway, I'm looking for ideas!
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