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BMS and Inductive Loads
#1
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.

Thanks
#2
DIY Battery Project Builds is for "Project Builds and Progression", not questions on how to build them. Those go over in "Battery Pack Design, Planning, and Building" or "General Project, Battery, and Electrical"

This thread is posted in the wrong section. Closing.
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