I wouldn’t have added an extra capacitor either if I knew these minis would end up in a 7S build (happened to resurrect my old board with some 25Ah NMC cells ). My intentions were different from the beginning and there were few reviews out about the robustness of these escs. I have replaced enough DRVs and I was unsure about this HW design since there were no electrolytes.
Seemed like a sound advice from @linsus earlier and as I said, the guy who designed this esc later gave me the same advice… i think
7s using those 25ah NMC cells must be incredible, im amazed you could find space for them. A lot of stuff seems to get lost in translation with these retailers, unfortunate really I think they have mostly good information.
Alright, I need some help here. I’ve got a couple of these, but it seems like I can’t update the firmware. It’s on version 3.63, and I need an update so I can do the config wizards.
Every time I try and update, it doesn’t stick. Gives the same firmware version when I reboot.
EDIT: Search function is useful Needs a bootloader update, will try that and report back.
EDIT2: Yep, a bootloader flash worked. Odd, I’ve never had to do this before and I’ve used probably 7 brands of vesc.
@YUTW123 So I hooked up a power supply to the one of the VESCs setting the supply to 48V and 200mA current limiting. after about 30s the vesc shorted out and i had 3 ohms between plus and minus.
I had to desolder all the ceramic caps from the PCB to figure out where the short where and discovered sevral of the ceramics had internals shorts showing around 2-3 ohm when meassured with a DMM.
Whats the voltage rating of these caps? Also what tolerance are you using on them ±%? Normal practice is to have atleast 30% headroom on ceramics, 12S=50V+ so I’m hoping they’re 75V or 100V rated?
Kind of dissapointed to have failures on the bench, I’d imagine the avrage guy would hook this up to his battery, would be one big cloud of magic smoke with this one.
We recently discovered this problem: ESCs that use ceramic capacitors, sparks generated when energized will break through the ceramic capacitors. It is necessary to add an electrolytic capacitor to the outside. An increase is necessary … Unless using a Aint spark switch to turn on the power.
What you need to do now is to remove the shorted capacitor. Then add new electrolytic capacitors externally.
I’ve seen this happen before, 100V caps were blowing at 50V operation. We junked the reel of caps and changed cap manufacturer, problem solved. Caps should be able sustain their own inrush.
Is there any hope for a still slim redesign of the VESC casing to accommodate for the electrolytic cap? Keeping the cap tucked away and secured is a big plus, and I wouldn’t think it would be too be of a change to the VESC footprint.
Finding the shorted caps is impossible without removing them all.
Since they’re the same cap I’m replacing them all cause if one fails, others might as well.
I’m replacing them with 4.7uF 100V X5R ceramics. They’re expensive as fuck so wont fill all pads but I’ll use 10 and one big 15uF 100V X7R 2220 ceramic. After that I’ll add the electrolyte 2200uF on the powerleads. Its the best I can do atm.
). My intentions were different from the beginning and there were few reviews out about the robustness of these escs. I have replaced enough DRVs and I was unsure about this HW design since there were no electrolytes.
in the bed so be it 
Needs a bootloader update, will try that and report back.
. Wonder if I have this many 100V rated ceramics laying around somewhere…