To my understanding the erpm of 8s on a 245kv motor is 50764 erpm with 3.7 volts cell (29.62457=50764) and 57624 rpm with 4.2 volts cells (33.62457=57624). So even if the cells were fully charged it is below 60k erpm so it is completely safe to run a 8s 245kv setup with the vesc.
@jrpwit Thanks for helping, but I meant to ask Is much lower erpm than the limit is less efficient than closer to the limit?. Thanks. well my syntax sucks.
Anything under the 60,000 should be good. I would think that being close to 60k would be less efficient but anything under 60k will work fine.
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I bought one on these Trackstar motor analyzers and tested it on a couple motors:
TB’s 6355 230kv Result 197kv
Alien 6355 190kv Result 172kv
Both motors had results lower than there rating.
You would think that this analyzer could calculate KV at any rpm but it doesn’t seem to work that way.
As I turned the knob and increased rpm, the KV went higher.
Because the rpm is limited to 2s voltage which is the max this analyzer can handle, I believe that it is not giving a true analysis of either motor.
Bottom line, this analyzer was a waste of money.
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I used the VESC and calculated kV using erpm, duty cycle, and voltage measurements during bench testing and came out to 197kv on a 200kv motor with chaka’s help. You could try that.
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My TB 230kv motor is actually 198kv according to the VESC so that seems pretty accurate to me
Referring to the track star analyzer, why would the KV increase as the rpm is ramped up ? And it stops at 197 at 8 volts. What would it read if I could run it at 50v?
Good point
60k is what I’m shooting for. I’m gonna go with 10s and 190kv when my Vesc’s arrive.
Longhairboy has used 12s 190kv and hasnt had a problem or maybe he has and I just haven’t seen it yet
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.
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@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
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Not under full charge, however. That’ll hit 67k eRPM.
Can’t wait for the new vesc so everyone can stop talking about erpm!
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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.
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