The therm “too long” is relative tho. Every centimeter will add to the spike effect since it’s caused by the wires combined with the off switching/cut of high current. No clue if it applies to this but anyone with a decent oscilloscope can measure this effect with putting some load to the motors and hammering the throttle and set the trigger to for example 55-60V on a 12S system. I would be surprised if we don’t see this effect on Esk8 also as the multirotors is using much of the same gear. If the caps are big enough there won’t be any speak but if they are to small it will show.
Using the Maytech VESC on 8S/245kV setup I was happy for like 1 month of operation. Suddenly on saturday on a casual cruise it all started to act weird and left me hanging in the middle of the way returning home. DRV fault as usual.
After reading through the topics and opinions it’s still a bit covered in mystery of why it happens so many times…even when everything is correctly setup in BLCD etc. I do think that after we build our VESC enclosures, stack them with antispark switches with DROK’s, make them full and even watertight…what we do forget a bit is the airflow…I do think some kind of “ram air” like natural flow would help a lot…I mean, we can mount those little 40mm vents to blow hot air out too…I’m really starting to think all these chips are just capitulating because of lack of cooling…we can mount some passive aluminium radiators which do help but general cooling must be improved too. I’ll look into it more, I’ll try to monitor enclosure temp with & without decent airflow…maybe I’ll run an arduino pro mini with DS18B20 to understand the correlation a bit more…
EDIT: or BT module with online data of FET temps on the phone/watch.
plausible, heat increase resistance of electronics
On the topic of cooling I’ve got a bunch of these coming in for testing 
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@Minim the problem with hooking up an oscilloscope to your board is that you usually only see the voltage spikes when your actually riding your board and have some serious resistance on the wheels, like going down a hill or trying to stop a 150lbs person going 20mph.
@Crossfire I personally have heatsinks on both sides of my VESC on the MOSFET’s but adding one to the DRV is a good idea. I also have a fan inside my enclosure blowing directly on it which helped quite a bit but that’s off topic.
@scepterr those Peltier units might sounds good in theory, though the problem is that there so ridiculously inefficient there just going to create far more heat than it’s worth trying to cool one side of it. They also draw a ton of power so thats another consideration.
Do people know / think that with the new upcoming vesc tool , we are going to have a better working fw for 4,12 hardware ?
Sorry offtopic, but that’s kinda funny, I was once involved in a project to build a remote controlled snowplower, because of the budget and weight (friction) we went with leaded batteries, like 12x 12V/15Ah and if you used some of the batteries energy to heat themselves up, you gain capacity in total because lead batteries have a ridiculous bad performance at low temperatures 