I think Photorph said he face planted on his LHB due to some VESC issue.
I seem to recall that anyway.
I stand corrected then. 10s 190kv is probably the sweet spot.
@CSN is basically right. Well I didn’t face plant but yes I did fall off while going downhill and braking because of an intersection that was coming up…because the brake cut out. There is an issue with the brake cutting off because braking throws back more current than the VESC was prepared to handle. This happens during aggressive braking at speed.
There isn’t really a way to resolve it fully, besides not braking hard while bombing hills.
@longhairedboy can be a better resource about whether or not to use 12s with 190 Kv motors, since his builds are using 12s4p on a dual drive 190 Kv r specs.
2 Likes
@photorph This may be because of using the 63mm motors. Apparently they aren’t the best match for the current iteration of the VESC 4.xx, There is a thread where @chaka explains the concept in good detail. Worth a read! 
Did you try adjusting the regen current setting in bldc?
60000/7 8571/190 45v 190kv might be within safe range with 12s
1 Like
Not under full charge, however. That’ll hit 67k eRPM.
Can’t wait for the new vesc so everyone can stop talking about erpm!
1 Like
12S on Enertion 190kv motors with VESC is fine as long as you don’t slam on the brakes while bombing hills, which is kind of crazy town anyway in my opinion. The motors run warm but not too hot, and the oomph you get from that voltage is lovely. If you give yourself time to stop so that you don’t have to slam the brakes its not a problem, you can even ride the brakes down a hill to maintain a low speed and never see this issue.
I never saw it happen until i gave @photorph his board and he went all suicidal on me trying to do 40+mph down a hill then slam on the brakes. I had to armor up and deliberately try to reproduce it before i ever saw it for myself. Scared me shitless when he first told me what happened.
Am I correct in my understanding that VESC 6 will resolve this issue? That’s what i keep hearing.
BTW that issue also happens at 10S if you put enough force against those brakes.
3 Likes
Have you checked the fault codes on the VESC after this? are you getting abs over current? I’ve read (on vedder’s forum) you can increase the Aboslute current up to 240 which seems a lot, but would prevent these (hopefully rare) large current spikes from shutting down the VESC momentarily. I think I’m going to slowly increase the value and see what happens.
2 Likes
Someone who is making some sense! Well said…
I think everyone forgets the settings in vesc can be changed…
Everyone just blames the size of the stator…
P.S. you can also change regen brakes and motor and at battery… trial & error is recommended
I wish people would stop saying this… its rubbish.
Screen grab of your vesc settings will help.
That’s sort of what i’ve been doing. The BMSs i’m using are rated at 80amps continuous so initially i started at 80 amps absolute max, but I’m going to keep bumping it up it till it stops. I’ve always based my motor amps max and min on what the BMS/cells are capable of handling comfortably, but that may not be precisely what’s required here. They can absorb some burst currents and i think things can be bumped up a bit to stop this nonsense based on what’s being said here along with the specs of the cells and BMS.
In fact if @photorph is ok with it i might hang on to his board a few more days (he sent it in for maintenance for which i don’t charge because i’m cool like that) so i can try to kill myself (figuratively speaking of course) a few more times on it and get this shit ironed out directly.
The rain lately has been very much in the way of things.
I know you use Supower’s BMS’s and I actually contact Lilian from them about this very BMS. Here’s what she said
Dear Pete,
The BMS supports Burst current. It will shut off if the current continuing over 80A, but for burst, it could do 100A for very short time.
It supports power switch.
yep that’s what my sheet says too. So this could easily become a game of who would you rather shut down first, the VESC or the BMS. Honestly i’m not sure the rider would know the difference, either way they’re at the mercy of their belt tension for slowing down at that point.
i’ll take all the help i can get. I’ll see if i can get some clean grabs tonight and post them. I’m no savant at vesc programming so i’m sure i’m missing something.
You could always bypass BMS for discharge and rely on the VESC and fuse for current control.
One reason i haven’t done that yet is because i don’t think the board will completely shut down when the cell groups reach minimum voltages if the discharge is still enabled and bybassing the BMS. Its not enough to tell people to get off when it gets to a certain voltage. You have to turn their shit off for them and make them walk/push or they’ll just light their feet on fire when the 48 tiny pipe bombs they’re standing on over discharge because we’re human and we like to think that bad things won’t happen to us and its only another mile what could happen.
I’m totally guilty of thinking this way. I’ve broken so much shit because of it.
3 Likes