Max safe phase current for ebrake?

[okie]

SVMC 72150 controller
QS 205 motor with 3T winding
72v 29ah battery with Molicel P45 21700 cells

I'm wondering how much phase current I can safely set for my ebrake throttle. The default setting of 50 amps had no felt effect, 150 amps had negligible felt effect, and 300 amps is within the realm of being useful.

I currently have regen turned off if that makes any difference.

 

[AGS]

I would like to know this as well.

I’m concerned about damaging my battery, so I have set my regenerative current to 30 amps which does provide a fairly useful amount of braking.

Mine works straight off the brake levers, so it’s all or nothing. I haven’t tried running regenerative braking from a throttle so I don’t know how well that works because I don’t have the wiring for the regenerative throttle on my controller.

I have read that there is a 10:1 ratio of regenerative phase current to battery charge current, but I don’t know if this is true. And I’m not smart enough to understand how to do the calculations.

If this is the case then 30 amps of regenerative phase current provides about 3 amps of peak charge into the battery to keep it well on the safe side.

I’m also concerned that setting regenerative current too high will damage the controller, for reasons that I also don’t understand.

I have an SVMC 72100 running a QS205 and I don’t want to blow the controller up either.

 

[dominik h]

I had run my SVMC72150 with up to 6kw regerativ bracking power controlled through the brake light.
Are you using a seperate throttle for the regen?

 

[AGS]

Were you using a lithium ion battery when you were running 6kW regen braking? I’m using 21700 cells as well as the op.

How did you calculate your safe regen current at this level for both the controller and battery?

 

[dominik h]

21S NMC 100Ah
Controller did make up to 14kw accelerating power. So I thought 6kw is ok.
My battery can handle 100A charge current without any problem. Single cell datasheet says 5C charge current and 8C discharge.
After the Sabvoton I upgraded the controller and the motor, now I'm running a Fardriver ND721800 set to 400A (33kw) .
The Fardriver ND72680 whichvwas installed in between the Sabvoton and the big Fardriver I had set variable regen up to 9kw. My 721800 does not support the variable regen via throttle and also not regen until the wheel stops.

Screenshot from one of my charger setups. This was with two Huawei R4875G5 connected in series [80A] and a Vertiv R48-2000E3 duo set to 32A.




Next stepp will be 9kw charging power from empty to full. The charger will be made from one Meanwell DRP3200-24 in series with the two Huawei R4875G5

 

[okie]

I had run my SVMC72150 with up to 6kw regerativ bracking power controlled through the brake light.
Are you using a seperate throttle for the regen?

Yes I have a regen throttle.