I’m trying to figure out why even at full throttle my VESC is pulling VERY little current and making me go very slowly. I have a VESC 4.12 attached to a 6374 190kv motor. It’s running off a 12s, 10,000ah lipo. I’ just finished rebuilding my board after a slue of issues but can’t figure out the source of this one. Can anyone spot my issue? It is persistent even after I swapped motors.
Is the problem with my VESC settings, VESC, or battery? Thanks!
If that is the actual mosfet temp it’s thermal throttling like crazy
Good to know! Its a new torqueboard VESC 4.12 - I couldn’t imagine how it would be so hot.
Did you ride it before taking the screenshot?
Turn the board off for like half an hour and check the temps again, leave it on for like five min and check it again.
Temperature should be the same or lower the second time you check it, if not I’d say something is wrong with the vesc.
Mine are usually at ambient temp when powering on and 20°C hotter when in use, 85°C is really hot.
It is DEFINITELY the mosfet temperature - nice catch! I turned the board on and it worked GREAT for 10 seconds going all the way up to the motor max of 57a and then quickly thermal throttled. Within 1 min it went from 30 to 85 degrees C!
Is the solution to buy a new VESC or mount my current one better? Its currently epoxied to my enclosure.
People complaining about their build being éco and efficient, heh
is it fully epoxied in? if so that’s probably causing high temps
It isn’t fully covered, just around the edges of the VESC. I will try a different attachment mechanism and see if it helps. Thanks!
At 12S and 190kv you’re going to be over the 60k erpm limit of the 4.12 when going full throttle, not sure if this has anything to do with it.
No not actually, there are so many losses that you dont actually get near the 60k ERPM limit at 12s/190kv. Its closer to ~55k ERPM going downhill at max throttle which is close but its been good for ~1000km now.
If the heatsink is incased in resin against a hard thickish surface you’re losing its ability to release the heat so its going to bounce back directly onto the chip. A picture of your electronics would help. I like to mount my heatsinks externally or at the very least face up. I’ve also used a 3mm thick flat aluminum sheet that I epoxied to the outside of my enclosure, I then cut a hole large enough to fit my vesc’s heatsink and attached it using heat transfer tape and silicon sealant.
Thank you all for the help! I ended up installing the second motor and VESC and also building a LARGE heat sink out of some scrap aluminum.
The heatsink is similar to the designs of some other people on this forum. However, I put large plate on the top as well as the bottom FETs, connected them together, and cut fins in them.
As a result, I no longer have the power throttling issue! Thank you all for the help!
It’s an extravagant solution that I didn’t expect to see conclude this thread but hey if it works, power to you haha
The real question is why was it having a problem in the first place… My TB 4.12’s have never gone over like 60, in fact I don’t know if they’ve ever even reached that
That’s a really good question! I don’t think I mounted them weirdly or anything so maybe there was a problem with the ESC. I was only check the temp on one (only have one BT module) so maybe the other was fine. I could have a defective ESC or something in my setup might just be abnormal. Honestly though, its all good with me now that it works!
VESC 4.12 thermal throttle a lot with sustained load.
