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BMS and Inductive Loads
I have issues when powering an inductive load such as a motor used in a hand vacuum. Originally the vac used nickel metal cells that eventually died so I attempted a 4s 18650 replacement. I discovered that with two different BMS boards I tried, neither would start the vacuum. The vacuum motor is fine starting and running without issues when the 4s pack is connected to the motor without the BMS. Apparently, the di/dt inrush and the reverse spike that is created caused the the BMS to immediately shutdown with the motor receiving just enough current to allow the motor to spin with a very Shirley duty cycle of about 1/4 sec. I also discover that if I continued to switch the motor on and off rapidly I was able to get the BMS to allow the motor to spin up enough to sustain constant normal operation. That’s why I believe the starting issue is related to the classical di/dt current issue. This would suggest the same issue with any other inductive load. Has anyone else experienced this and discovered a way around it?

I’ve tried Schottky diodes in reverse in an attempt to dampen the reverse current but it’s not reliable using even a PN junction diode. Looking for comment regarding similar experience and mitigation suggestions.

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