Battery Amps low at acceleration, slow acceleration

ESK8 Electronics
21

Hmm, if I am thinking about this carefully, when you start from a standstill and throttle 0-100 then you will achieve the maximum torque you can get with your motors (also assuming you run FOC meaning start up is efficient). Though, running BLDC will dump amps aimlessly giving an insane amount of power to the motors not caring about the load at all. But still in the end it takes X amount of power to make a motor turn. If you had infinite amps to dump and a VESC to be able to dump that much into a motor, then your motor will henceforth be heating up as well as giving you your torque with the limit being the motor’s capabilities.

skip to 2:45

Trampa Streeet Carver: 6374 190KV Motors 12S4P Battery on Samsung 30Q 16/40T 100mm MBS wheels shaved at 95mm

Sector 9 Bintang 6355 230KV Motors 10S4P on Samsung 30Q 15/40T ABEC 11 Flywheels 97mm

22

Oh and forgot to put but the reason why bigger is better, is because bigger motor= bigger magnets which is bigger pole = more torque.

23

Yeah I should but I don’t. Running FOC like yourself. That’s what I mean, I should get max power when the throttle is pressed all the way. That’s why my confusion why it doesn’t use more motor amps when it is not even close to the limit and yet I wanna accelerate harder and am already pressing the gas full way, yet not reaching any limits… I do not have infinite amps but I am satisfied with those 70a if possible :slight_smile:

24

Thanks for the video, there doesn’t seem to be a big difference in acceleration between you two, after a few seconds your friend then keeps going full power and you back off, right? Will get those 6374 motors. Meanwhile still need to find out why the motors aren’t getting the full motor amperage at roll outs. Thank you again.

25

I don’t take credit for the vid, it’s one that I saw a long while ago.

What’s your vesc settings? I think maybe you haven’t given it enough juice to give the acceleration you want.

26

What else is there except for motor amps, battery amps, wattage limit… The thing is I used to have much more torque, I know that was with urethane wheels but my max speed is almost the same and I ride with 70PSI trampas that are hard as a rock. I can feel I lost acceleration in past week or something like that. It’s weird, I switched to regular vesc firmware where the throttle control is AMP based, not that it should matter, but wanna see If there is a difference.

27

That does sound very odd, if you have the same top speed then I assume that you have geared the drives to have the best amount of torque to accommodate for the larger wheel size. I don’t have this issue, but it just got better when I switched from 6354 to 6374.

28

You should definitely be getting max current on the motors at full throttle

How are your voltage cutoff configured? And do you have any ramping set for the remote?

1 Like
29

sounds like its maybe entering cutoff :thinking:

2 Likes
30

Hi, I have it set for the regular cutoff for 12s that vesc tool offers. I don’t get full motor amps even with full battery right at the beginning. I switched to default vesc firmware today and was looking through metr.at data and my motor amps did raise. Yesterday I had 2 times around 110a and today I had 5 times around 130. Which is reaching the limit for 2*68a per motor I have pre-set. SO my motor amps did raise after switching firmwares. But still I expect to get full motor amps every time I am going slow or standing still and pressing the throttle at full. So more confusion now… I have reached the motor amps but only a few times and also firmware affected my output… I tried long start on a slight uphill with full throttle for like 5 seconds, the first thing after fully charging my battery. I only reached 117a (those 130 reached were later on during the ride so If it was battery potential or something it wouldn’t be able to give more amps later on with more drained battery. I kept thinking about ramping time, will that affect motor amps? I have it set to the default values, haven’t messed with it.

31

Could share the Metr logs and screenshots of the VESC tool?

32

https://metr.at/r/sBDdm this is with ackmaniac firmware. https://metr.at/r/jwlwG this is with regular vesc firmware

You can see higher motor amps with regular firmware. Both had the exact same settings.

33

I think you would want the WATT CONTROL mode or whatever its called, but PLEASE do research for those modes before you use them, as Ive heard about breaking being VASTLY different on that mode VS BLDC ( as soon as you turn the throttle down)

34

I love the ackmaniac’s watt control mode but as you can see I am getting more than 10% less motor amps with ackmaniac firmware in comparison with regular vesc firmware. Watt control is better and smoother I must say but wha’ts up with the motor amps being lower

35

When dialing in your remote via PPM do you calibrate it?

36

e: im an idiot nevermind

37

Yes I do calibrate it. I will try to shorten the ramping time but still the amp differences in watt control vs amp control is weird

38

any shot you can just factory reset with regular firmware? IE what it came with?

39

that’s what I did, that’s the regular default vesc fimrware. max motor amps went to more than 10 percent more. Still not using max motor amps every time I pull the trigger to full from a slow speed or standstill. Only a few times has it come close to the max as per the data shown.

40

so odd. Im sorry I cant help any more, I dont know all that much about VESC

It sounds silly but have you thought about the FW_NO_LIMITS or whatever its called? The software that removes all built in MAX values, and sometimes enables VESC users to run their HW normally