We are building a bar telepresence robot using two BLDC motors (scavenged from a hoverboard), two 500W motor drivers like this one and an Arduino that processes input from a RC receiver to deliver the speed and direction inputs to the motor controllers. The motor driver side is powered by a 36V LIPO battery (from the original hoverboard), the Arduino is powered by a USB battery pack. The ground of the Arduino is connected to the 5V ground of both the motor drivers.
The left-hand motor and driver have worked perfectly since the start. The problem is that so far three right-hand drivers have failed and I have no idea why.
The damaged motor drivers:
- Failed when not under load - they died when the 36V battery was first connected. One was working perfectly for a while, but failed when the battery was connected again later.
- Smoked a little, but I'm not sure from which component (and I can't see any obvious damage)
- Two of the drivers failed in a way that shorted the 36V power input (I'm glad they didn't cause a fire)
- The third driver failed in a way where the inputs on the 5V side had a greatly reduced impedance
There are some differences between the working driver and the failing one:
- The working driver is much older (it was bought about 3 years ago when we first looked at this pre-pandemic)
- The failing drivers have come from different sources on Amazon, but they all look very similar
- The failing driver has longer leads running to the battery, and the wire used is thinner than the working driver.
Does anyone have any clues as to what might be the problem?
Finally I am a software engineer and have very limited electronic knowledge so please assume I am an idiot!