Hi all, I need some advice before talking to Maker X. So I had their mini vesc for a bit, running happily on a 10s2p li-ion battery. Yesterday I swapped it out for a larger 13s3p li-ion battery, and as I connected it, the vesc had a crackling sound inside and a puff of smoke came out. RIP. The battery was at 46V at the time, it has 20A BMS and a 30A fuse, so there couldn't have been enormous current going through for any reason. The vesc is rated at 60V, 30A, so everything should have been within limits. I opened up the vesc and here's what I saw:
The only other change apart from the new battery was that I soldered some longer wires - not to the vesc itself, to the original wires from the vesc. I don't believe there was any significant heat transferred to the vesc, because it was just a wire-to-wire solder, 10 seconds heat exposure, at a distance of 8-9cm of wire.
So what do you people think? What's going on here, my mistake somewhere, or should I take the issue to maker-x?
Thanks in advance.
Got an answer on reddit, case closed. Long battery wires are a huge nono, as you may get higher-than-battery voltage spike due to induction in the wire and the connector. I must have picked a too long wire for my setup, and shot through the 60V limit on connect.
These drives only have a small amount of ceramic capacitors on the board. They need additional large electrolytic/polymer/hybrid caps if you have a lot of input inductance (long wires).
And the initial inrush current is enormous with those ceramic caps.