I wasn’t able to collect any telemetry data, but the ESCs handled more smoothly than the previous VESCs I was using.
I was drawing somewhere along the lines of 15A from the battery on each ESC when climbing hills, and phases currents went up to the 30A range.
One issue I encountered is the ESC throws a DRV fault during high torque stall conditions and sudden changes in acceleration, I would think it is an overcurrent fault, but the VESC 4 schematics shows that OC faults are disabled, so not sure what is exactly causing the DRV fault. During bench testing, the reported current was well over 40A and into the 50s when the max motor current was set to 40A.
Just to be clear, the fault is thrown only in extreme situations that most riders should avoid in the first place.
I had motor current set to 40A, battery current set to 20A on Field-Oriented Control.
Overall, I am pretty satisfied with the mini FSESC 4.20. Sometime later I see if I can hook up an HC-05 to collect telemetry data.
Only when you tell to controller to go from 0 to ±40A in under two seconds.
When it does throw the fault, it simply lets the motor freewheel.
The fault clears quickly, letting your remote return to center resets it.
Like any controller, always best to ease up on the throttle.
I am almost certain that if I tried to same thing on my TB ESC, the DRV8302 would’ve blown up a second time.
That’s because I normally avoid the situations that cause it to throw the fault, which were very high torque stall conditions (like 30 or 40% grade from standstill to vroom), and very sudden changes in acceleration (lets go uphill at a calm 8-10 mph then FLOOR IT AND SLAM THE BRAKES!).
Just to be clear, it only throws the fault in extreme situations that most riders should avoid in the first place. I’m guessing the firmware for the VESC 4 has issues with current regulation at stall, (since it only uses two low side shunts; any piece of software would struggle with that since current changes so quickly and you can only measure it so often. Changing the current control PID loop to accommodate stall would make it unresponsive everywhere else) and my previous 4.12 VESCs (one of which is from DiyElectricskateboard) had even more issues with hill starts.
For the record, given reasonable settings and setup, I don’t think full throttle under any circumstance is extreme, and any esc that pops under full throttle, in my honest opinion, is a toy. My measly hobbyking 4.10 handle this kind of use (not abuse) every day.
It works fine when you ease it up to full throttle; the fault is thrown when you go from zero to full throttle as quickly as positive ramping time will let you on a 30% grade.
One of my friends did the zero to full throttle thing on his electric skateboard, he was using those big 6374 motors with 15/38 gearing; the board shot out from under him like a rocket, he weighs 220 pounds.
Respectfully, I think that’s faulty behavior, and I don’t think you should give any esc that behaves this way a pass. Even meepo, etc are fine with throttle jamming.
It might also be my motor setup, I’m using hoverboard hub motors that I reterminated into delta configuration; this results in very high magnetizing currents.
I said “flooring it” causes the fault to be thrown, which indicates a very high torque demand. This, in combination with my motors, is probably causing an extreme situation that causes the DRV fault.
I might test it sometime with a 5065 or 6374 motor, maybe with those motors I can floor it with no problem.
If you want to floor it on your skateboard, then I’ll concede that the mini FSESC 4.20 is not for you, something VESC 6 based would better suit that purpose, and I also have mad respect for such daredevil behavior.
The mini FSESC 4.20, true to its name, is better suited for more tame purposes :).
I share here too :
I made a little vid on my unpacking, 1st review, setup, test ride, and “safe” parameters …
If it could help!
To bad that my phone scratch metr.at apps every time, I haven’t recorded a full ride, but you could find some extracts on my MAD SURFER Build) cause I made some interesting ride test I think.
1st I start with the paramter shared here that was supposed to be ok (40A motor max, and I put only 30A batt max /esc).
But from the 1st 300m I got OverCurrent faults when going uphill, and it was my 1st ride on the MADSURFER so I go really easy …
Then I made stress tests with going full throttle uphill and braking almost to stop then full throttle, many times, same on flat etc.
On flat at 30A motor max and 25A batt max, it could be ok, but when uphill it faults again…
So I think, try many many setup with the metr.Pro during 2 battery pack of ride test.
Then I find that at 20A Motor & Batt Max all is ok, you could stress it without limit and it responds to the trigger! But the ride is really not kicking ass actually.
20A Motor Max / -20A Motor Min / 20A Batt Max / -15A Batt Max / 90A Absolute Max
is the safer parameter I find… I made another ride (I’m about 2 more battery pack only with setup parameters).
If they’re good point, it’s that they don’t heat at all, the range is really good (better than a single 6374 with 4.12 vesc at 50A haha), and you could get a better brake.
This could be nice to pass from single to dual setup, but with same power as one VESC.
motor amps and battery amps are not the same. as far as my understanding goes, motor amps dont throw abs overcurrent, its whats beeing pulled from the battery. just try it.
motor amps can be bigger than bat just because voltage * bat amps = max power so motor amps = max power / duty * voltage
For e.g. Voltage = 50V Duty = 0.5 (50%) Bat Max = 30A
Max power = Voltage * Bat Max = 1500W
So at 50% duty max motor current is (Max Power / (Duty * Voltage)) = (1500W / (0.5 * 50V)) = 60A but when duty reached the top maximum value (0.95) (1500W / (0.95 * 50V)) = 31.5A so you get limited by bat max as you near full voltage.
So for e.g. at slow start you can consume (Duty 0.1) (1500W / (0.1 * 50)) = 300A but you limit it by Motor amps
Don’t know if I explained enough but I think it would make more understandable about bat/motor amps
So basically as long is with in feasible values you can put motor max as high as you want because would be battery max so max power to limit it. Is it right?
True. But let say that a motor is rated for 50A. By pushing it to 100A if your vesc and battery allow it you will probably imhit that new limit only at starting and maybe make the ride smoother and better acceleration. I am just wondering about it.
Yes, it is that @Benjamin899 , but as my test fails at 40A motor max, why do you want me to test at 60A … To make a bigger fail ?? I dont understand the point here. I could make the test but for what ?
if at 40A/30A and 25A motor Max it makes overcurrent faults why try at 60A ?!..
(I try itch at 30/25 and 20 Batt max)