Need advice: What amp limits to use?

ESK8 Electronics
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1

I’ve been trying to read up on this but it’s all going over my head so please don’t post the search link…I tried but I’m just dumb

Parts:

  • 12s4p Samsung 30Q 18650 pack
  • MayTech 50A/240A dual ESC (for each motor)
  • Dual MayTech 6355 (rated 65A max)
  • 11:25 sprockets and chain on 90mm wheels

What I think I can do:

  • 30mph for 40miles (using the esk8 calculator and assuming 11mi/wh
  • pull 80A continuous and maybe 120A burst

What I think is the right amp limits:

  • Motor -30/65 each
  • battery -40/80

What I’m being told:

  • Motor -40/40 to -60/60
  • Battery -30/50

Mathematically what do you use as the limits? I’d imagine that max motor amps is the rated max amps and the max battery amps should match the max charge rating and the burst discharge with a safety factor, and that the regen braking for each motor should add up to the recharge value but I know that the resistance and duty cycles change them drastically

Why am I an idiot

Note: The board and me combined is only 150lbs/70kg so I’m gonna get HELLA ACCELERATION (calculated 3m/s/s on start-up)

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2

Run em @ 60/-60 and go from there

That’s 30a per esc

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3

30q does 20a cont with minimal consequences, so a 4p pack can output 80a max, and each vesc should be set to either

  • 40a / 40a - for maximum power(this is gonna knock your socks off, be careful)

Or

  • 30a / 30a, for a build with slightly less acceleration and a significantly longer range (40a per motor is draining af!)
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4

i weight like 73kg, with a board that has dual TB 6355 and i want more acceleration, its not as fast as you think

5

Damn…that’s just depressing…what’s your gear ratio and wheel diameter?

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6

16:36 mbs 100mm wheels

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7

maybe try 16/40 on that size wheel

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8

i like my top speed being 60kmh :slight_smile:

9

what vesc and what motor settings are you using?

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10

dual flipsky 4.12 running on 12s motor max 60a bat max 30a

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13

What do you mean?

14

Is the ESC amp limit the max in from the battery or the max out to the motor?

Also updated original post

15

Change that to Motor -50/65 each Battery -12/40 each

16

Well that’s where your lack of torque is coming from.

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17

yea, still a very nice speed though to accelerate

18

Also new here so feel free to tell me why I’m an idiot - but can you tell me how the dual ESCs are going with dual 6355’s … Im hoping to run a single FSESC 4.12 with a 180 kV 6374 but theres so much mixed info on VESCS, some on this site saying they’re limited to 27A continuous which seems unlikely and would surely bottle neck the hell out of almost every build ive seen here…

TIA

19

Max batt continues is 35a. You can try to get higher but I would monitor the temperature or get there heat sink case for the 4.12 vesc.

20

Thanks, So the rating of 50A is more of like a hard limit? Will 35A not severely limit the motor…?

21

Bat amps not motor amps. You still can set your motor max to 60a for example.

22

27A is “real” continious without overheating, everything above (continious) and it’s getting hot. Of course you can set the batt max higher than that up to 50A but (in summer) the esc’s will reduce power or shut down when hitting temp limits. I would try 35A or 40A first.

Is this for 4.12 as well? I thought that was the limit for the mini fsesc 4.20 only because of over current faults.

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