I am having issue with extremely weak braking on my setup. I’m using 2x Flipsky 6354 190kV geared at 15:36 with 90mm wheels. It is powered using an esk8supply Dual VESC and 10s3p 30Q battery (BMS bypassed for discharge).
The issue:
when I’m traveling at a higher speed (>10mph), and need to break the breaks are extremely weak until I get under roughly 5mph and then they get ridiculously powerful (like belt slipping powerful). I’ve tried changing a bunch of settings incl negative ramp time, motor negative current, battery min etc. BMS is also bypassed so there should be nothing stopping the regen current.
Continuous long-period charging limit is 4A per cell but for brief braking you can exceed that, even by a lot. Because it’s brief.
I would not freeze a mostly-drained battery and then skitch on the back of a car, in the winter, braking trying to charge your pack. That can damage the cells.
Normal skating and braking with a battery that’s not frozen (Even using throttle in sub-zero temperatures heats up the battery into the safe zone) won’t damage the cells.
People don’t realize but the most wonderful thing about lithium ion batteries compared to lead acid is there technically isn’t a limit of how much current you can dump into the cell or realistically take out.
You’re simply limited by temperature and lifespan of the cell.
All the cell ratings and spec sheets are simply a sheet of how the cell will perform in most circumstances. Take the 30q for example which is a spec’d 15A discharge cell that can do 25A with a temp cutoff no problemo.
Sure sag and other things definetly come into play, but if you wanted to you could dump 100A into a single 30Q and it probably wouldn’t blow up, for a few seconds.
For a community that is so against running discharge BMS’s its awfully interesting people run such conservative battery regen Amps…
also I’ve never been the guy to post my build since they don’t always end up great so just fyi this isn’t my first build/mod but it looks a little fucked because I still gotta fix some stuff on it.