View Single Post
Old 03-22-2009, 01:14 AM   #609 (permalink)
MPaulHolmes's Avatar
Join Date: Feb 2008
Location: Maricopa, AZ (sort of. Actually outside of town)
Posts: 3,832

Michael's Electric Beetle - '71 Volkswagen Superbeetle 500000
Thanks: 1,368
Thanked 1,202 Times in 765 Posts
That's a good question! It is less than or equal to 500 MOTOR amps, but the exact amount is a bit tricky to figure. I have a homemade ammeter whose accuracy remains unknown to me. Plus, it measures battery amps, which is different from motor amps.

In fact,

Ibatt = Imotor*PWM_DUTY (or close to it).

Hey! I could use that formula! haha, but I'm never really sure what the PWM duty is while driving.

I know for sure that the hardware shuts off the mosfets each time the naughty 500 amp like is crossed. Right now I wait until motor amps drops below 500, then wait 1 PWM period, then turn them back on. I have no idea how much the current decays in that time. So, I would guess that the current limiting is something slightly less than 500 amps. hehe, sorry for the vague answer. The acceleration feels stronger than the 400 amp controller, so I would guess that it's more than 400 amps.

The battery amps read about 320.
kits and boards
  Reply With Quote