Need help with VESC settings.

[broke_esk8er]

Hey everyone, I need some help dialing in proper battery settings on my VESC.

Relevant specs:
12s4p 30Q
Dual Flipsky 6354 190kv (not the battle hardened model)
Flipsky 6.6 Dual (the normal version, not the plus)

Current setting for each side of the ESC is as follows:
Motor current max: 60A
Motor current max brake: -50A
Battery current max: 40A
Battery current max regen: -8A

I’m having weak brakes, which I expected when I dialed back the regen to -8 amps per VESC. However, that’s what I calculated the max charge current to be for this pack (a total of -16 amps). How high can I set the regen so that I’ll have strong brakes, but also won’t diminish the lifespan of the pack?

[b264]

@broke_esk8er

Battery current max: 40A
Battery current max regen: -8A

These both look high. Try lowering them to

Battery current max: 25A
Battery current max regen: -16A

[b264]

@broke_esk8er

However, that’s what I calculated the max charge current to be for this pack (a total of -16 amps). How high can I set the regen so that I’ll have strong brakes, but also won’t diminish the lifespan of the pack?

@b264

Typically the high regenerative charge rates achieved by smashing the brakes at a high speed will be so ephemeral that they won’t upset the cells.

If sustained, a charge rate that high could definitely be an issue. But once you start braking hard, you immediately begin losing the momentum that would be needed to sustain such hard braking.

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[broke_esk8er]

Why does 40A battery current max seem high? If I’m not mistaken, the max discharge rate for this pack should be 80A?

[b264]

@broke_esk8er

Why does 40A battery current max seem high? If I’m not mistaken, the max discharge rate for this pack should be 80A?

While that may be the case, it’s similar to saying that since your sedan can go 125mph (200km/h), that you should just set the cruise control for that speed the next time you get on the freeway. That will likely cause accelerated automobile wear, legal problems, be less safe, be more expensive, and reduce your fuel range.

Not running your battery at its full capacity gets you more range, your battery lasts longer, is less likely to fail, and running your ESC at lower “battery amps” means it’s less likely to fail, and less likely to overheat.

The real question is, do you want failures or not? Based on your username, I would limit battery current.

[b264]

@broke_esk8er

Motor current max: 60A
Motor current max brake: -50A

These are probably fine as-is

[broke_esk8er]

Completely understandable haha, and you’re damn right on my username. I’m dead broke. Since I’m reducing battery amps, I’ll bump motor amps to 62 amps. These flipsky motors can handle up to 65A, which is a tad close, but it should be alright, right?

[b264]

If the motors are rated at 65A, I would bump that all the way up to 65A.

In general, that’s not going to increase failures like battery amps will.

[broke_esk8er]

Okay, I figured. Motors thermal throttle themselves from what I know

[b264]

If you run too much motor current they will start cogging. So really you can turn it up until they start working badly then turn it down a little bit.

Raising motor amps will make the board “feel torquey” and start from a stop much better. Braking at lower speeds is also affected by this.

Braking at higher speeds is affected mostly by the battery amps.

[broke_esk8er]

Yeah, I discovered the high speed braking thing on my own a couple hours back when I test rode the board at -8 battery amps per ESC. Braking power progressively ramped up as the board slowed. One more question, for some reason, one of the VESCs over CAN seems to invert its motor direction when I change motor settings. No idea why it does it, any recommendations?