My specs: Samsung 30Q 10s4p, 6374 192kv turnigy motor and the maytech vesc
I got this vesc and after 2 weeks of use it broke. I do not know the problem and sent it back to maytech. There it was stopped by the import people, and I had to pay 70 $, so I got a good prize from maytech and got a new one. I thought my parameters I used were good, and when I got the new one I sent my parameters to maytech for them to check. Turns out my parameter on the -50 A engine brake was way too high and I should ONLY use -15 with my -12 battery regen. With this I have no braking force at all, but I can not understand why it must be so low? On the last vesc (focbox) I used -50 amps, and it never stopped. So I asked them and got this answer "Please check article below:
Motor Current Max Brake, should be generally set 10A higher than Battery Current Max Regen.
Battery Current Max Regen should be set according to 80% of the maximum charging current that the battery/battery protection board can absorb.
Is this really the case with all vesc or is the maytech’s vesc just that bad? If it is the case what would be the best parameters to use for braking? I was thinking -30 motor brake and -20 battery regen.
Those seem like some arbitrary numbers that are there to void your warranty tbh. Motor braking amps can be the same or a bit lower than motor amps on pretty much any vesc based esc. Even the wizard inputs the same values.
As for battery regen… i use the max my pack can charge at x2. It can be higher quite safely. You’ll only ever use the max value at very high speed slamming on the brakes. And even that will be 10 sec tops.
Some play it really safe and barely go over the slow charging values but that’s just deadly when going fast.
If those values stated by them were true, i’d have to use 4wd 63100 with a 10p pack and i’d still get in shitty situations fast
Regen is usually motor amps -10 to be safe, and battery regen amps can be 2x fast charge rate for cells divided by the number of vescs since you dont charge for long periods at a time.
Also, point 2.6 (on maytech link) is utter bullshit.
They either have no idea what they’re saying or oversimplified until they lost the entire point.
If a motor can brake at -100 amps but vesc is programmed to do -60 amps motor and -20 amps regen, the vesc will brake at 20 amps at full speed, -40 amps at half speed (assuming motor specs and the fact that the battery regen settings is the bottleneck) and full 60 amps at lower speeds.
At no point does the vesc pass the -20 amps battery regen set value, or the -60 amps motor brake value.
If there is a bottleneck (almost always battery), the esc will throttle it’s capability to be under that programmed value.
The heat they’re talking about is only losses. It’s the same heat generated when accelerating, only now when braking it’s really inefficient.
70 A motor
~45 motor brake (i try to keep in mind that a single wheel will slip if abused. Try and adjust yourself)
70A battery (30q is UP TO 20A/cell capable. With 70A/70A motor/battery you will only ever draw the full current at top speed full throttle while still accelerating. I dare you do that lol)
-32 battery regen
One advantage of having same value for motor and battery is you will have linearity in throttle. You will feel it when you push that throttle at any speed.
Like @Athrx says there is a change of the belt slipping or motor losing traction at higher brake currents. But its a better feeling knowing you have more braking power available than you need, when you need it instead of underpowered brakes. Since esk8’s don’t have ABS it’s a case of getting to know your board and not mashing on the brake but easing into it and releasing it slightly when it locks up.
Also, look into replacing that ESC. My numbers are only relevant with an ESC that is built to actually handle those numbers. Otherwise start conservatively with motor and battery amps and work your way up until you get drv errors (and then back down a little) but not broken hardware.
My dude, if you live in Norway please consider investing in a dual drive setup. I live in the flattest country in the world, aka The Netherlands and still find the brakes on single drive unbearable.
Depending on the wheel, you may never actually reach that speed while actually riding it (12s4p pneumatics here. Geared for 55km/hr and it’s a task getting to 50… with 3kw power running through as well)