I had my VESC from OllinBoardCo up and running for about a week with no problems, but that all ended Saturday afternoon…
It died under very innocuous circumstances; I was giving short, back-and-forth rides to my 45lb kid on the sidewalk when it just stopped responding. I power cycled it (big mistake, wish I would have pulled the fault code doh!) and still nothing. I then go inside and hook it up to the computer and pull faults and get the dreaded DRV_8302. VESC still connects/reads/writes fine, but any attempt to drive the motor results in 3 red LED flashes and a DRV code.
There are no obvious shorts and it has never been wet. I kept the shrink wrap on and all leads were well connected and insulated. After this happened and I removed it from the board, I removed the shrink wrap to see if I could see any glaring anomalies (yeah right, how in the hell do you wizards solder these things?!?), but there was just a little dust.
Earlier in the day, I was playing with the motor current and absolute current settings as well as FOC. Here are the settings and results…
Vesc 4.11 hardware with c18 mod done by chaka, 4.15 firmware. Single Bigfoot 160 245kv on 8s Lipo. 15/40 gearing on 83mm wheels- top speeds between 25-26mph on the flats.
Motor Mode: BLDC Motor Current: 70a Batt Current: 60a Abs Current: 130a Results: Mostly excellent, this was the setting I used most of the week and put probably 50 miles on. I was able to induce the occasional cut-out on full power starts. When I pulled that code, I got a couple of ABS over current (just barely, like 130.3 amps). So, of course I up the absolute current- saw a post of Vedder’s where he says do not go above 150 ABS amps, so on to the next setting.
Motor Mode: BLDC Motor Current: 70a Batt Current: 60a Abs Current: 150a Results: Great! No codes, but I wanted a bit more so I upped the motor amps
Motor Mode: BLDC Motor Current: 90a Batt Current: 60a Abs Current: 150a Results: Very sweet acceleration and the mid to full power range felt great and just dangerous enough to be exciting. Cool, now lets try it on FOC…
Motor Mode: FOC Motor Current: 90a Batt Current: 60a Abs Current: 150a Results: Major cut-outs on full throttle accelerations (all slow rolling starts as starting from a dead stop feels bizarre to me). I pulled the codes and got an ABS over current of well over 200 amps! (I didn’t save this one, unfortunately).
So I reflashed back to the BLDC, 90amp motor, 60amp battery, 150amp absolute and was happy. It was using this exact setting that the DRV died, but under next to no load with me giving baby rides.
FOC mode on this motor was working as intended, except when I would coast at moderate speeds (maybe over 15mph) and then try to throttle back into the power very slightly, I would get a buzz-like short sound and slight braking force as it felt like the motor was trying to sync back up? The faster you go, the more braking force was encountered and it made the board difficult to control under FOC.
What do you think? Were my amps too high? Did I do damage with the FOC over current? Motor never got over 55c (infrared thermometer immediately after some hard hill pulls) and I never saw any mosfet heat related codes, but I wasn’t actively monitoring during any of these rides either.
I’ve got an e-mail into chaka for return/repair service, so hopefully I’ll be up and running again here shortly.