ESC rating... Amps vs Volts

[Brushless55]

Ok question for some..
and I hope I make sense in this all..

Looking at HV escs
lets say one is rated at 130amps at 12s, that would = about 5772watts
so could we take that same esc on 10s and pull 156amps through it to make 5772watts?
or 8s at 195amps ???

just thinking out loud...

[m4a1usr]

Thats a good rational about electrical relationships. But. There are at least two factors to consider. Losses. Since amps are directly related to heat, current conductivity efficiency needs to be addressed as well. Then theres thermal conductivity. The hotter the FET's get, the worse they perform. So mass should be considered. I remember a good thread on RRR awhile back where Joerg was providing some basic assumptions but I dont have it linked. Maybe someone remembers?


John

[JIM MARCUM]

If you can find a 130 Amp ESC that is rated for 12S, at 4.2 Volts per cell, that would be 6552 Watts (4.2V x 12S x 130 Amps) max. Unless my calculator finger slipped.

Enough theory already. Get off the couch and take your boat(s) down to the pond and have some fun.JIM

[Make-a-Wake]

I wouldnt want to pull 156 amps thru a 130a ESC.................130a is maxxed out. You really would need to try for around 120a max with that ESC.

[Brushless55]

If you can find a 130 Amp ESC that is rated for 12S, at 4.2 Volts per cell, that would be 6552 Watts (4.2V x 12S x 130 Amps) max. Unless my calculator finger slipped.

Enough theory already. Get off the couch and take your boat(s) down to the pond and have some fun.JIM

under a load would be around 3.7v per cell... what most use for calcs on speed etc..

I wouldnt want to pull 156 amps thru a 130a ESC.................130a is maxxed out. You really would need to try for around 120a max with that ESC.

12s 130amp cont. 180amp max like this one...
http://www.offshoreelectrics.com/pro...-seaking-130HV

so if one were to try 8s and maybe pull 140-150amps cont. that would be about 4100-4400watts
so about 30% less watts than the 5772....

just throwing this out there, as I'm curious if I could get away with this....

[keithbradley]

It doesn't always transfer over that way, but it does a lot, and to a certain degree. I'm running 100A ESCs in my DF twin cat and pulling much more current than that.

[Make-a-Wake]

I just wouldnt risk a $150 ESC....................amps are amps. What is this going in?

[Fluid]

I am not an EE, but ESC designer Andy Kunz was asked this question on line once, and IIRC he said that amps is amps and what the OP is suggesting won't work. Second hand knowledge I know.....




.

[Brushless55]

I just wouldnt risk a $150 ESC....................amps are amps. What is this going in?

a Leo 5698 1100kv on 8s in a 42" Sprintcat

[Make-a-Wake]

Be very careful................that motor will suck amps big time......................prop it way down at first

[keithbradley]

Why not go with a lower kv and use the ESC within it's range?

[Brushless55]

Be very careful................that motor will suck amps big time......................prop it way down at first

may just spend the cash and get the new 300amp Steven has here

Why not go with a lower kv and use the ESC within it's range?

the package is on the way
this thread was a thought I was having about esc amps

[ozzie-crawl]

While the esc has a Amp/voltage limit that can be worked out in wattage its the motor that produces the wattage.
If the esc has a limit of 100 amps at 10 volts for EG, it would have a limit of 1000 watts. But the motor does not have 100% efficiency.
From what i understand a motors efficiency may drop to 20-30% on initial load and only give out 200-300 watts (as per eg).
So if we worked out our esc limit on wattage to produce 1000 watts when the motor is at 20% efficiency we would i believe see a 500 amp load.
I am no EE either and not sure if that makes sense but the motor makes the power (wattage) the esc does not care how much power is produced as long as the amps that are pulled by the motor or the voltage fed to it are with in its limits.