Watts is watts?

[Finnster]

Originally Posted by Serum

There is a contradiction in your post finn..

I don't think its important to make a big deal of the efficiencies.
and
heat gen is directly related to current

This is not true.

a 150A lurking motor on 10V can be more efficient than a 150V motor on 10A.

It IS all about efficiency. they higher the voltage, the less 'important' the resistance becomes But like i said, it's not just 'with high amps comes high temperature'

I was waiting for your post to that. ;) That is part of the point I was demonstrating with the 1950 6/HA, tho I had to cut the post off somewhere, so it got a bit lost. (My point assumes they have to be reasonable eff to begin with, if you have a 50% eff motor you have a prob.)

So unless I forgot my physics or I missing some other point, heat is a function of resist and current.

The motor is consuming a whopping 200A and remaining 94% eff. Impressive. But since that current is so high, heat gen is still signifigant. :dft002: But at 6400W @ 64V/100A, the motor could even be same or less eff and put out less heat. Thus you could run a poorer quality motor, but still have a cool system.
If the eff % are just changing a couple %, I don't see that the being the critical factor over the current you are designing to run thru the system.