How Many amps?
 

How many amps does a 7.5t pull with a 2 cell...roughly...trying to match up a ESC to a new 7.5t I just bought. Thanks

This depends on vehicle and gearing but I would think anything 70amp and over should be ok if using in a 2wd vehicle.

Yes it is a 2wd....thanks for advice!

Well if you go by say a Tekin 7.5 which is 352 watts. 352w divided by 8.4 volts is about 42 amps. If you go with a 60amp esc you should be fine with any 7.5 out there.
Vehicle and gearing has nothing to do with amperage. Maybe just strain on motor which will make it run hotter.

The higher the load on the motor, the more amps it pulls.

I'm not sure it's that straightforward. Seems reasonable to speculate that the 352W rating is close to a maximum output under a given set of test conditions. But at lower RPMs the motor will typically draw more amps with less power output. Also motor efficiency needs to be taken into account, takes more than 352W of electrical battery power to generate 352W of mechanical motor output power.

I agree it is likely that maximum current, at stall, is the same or at least close regardless. But vehicle weight and gearing, changing the load, can have a big impact on average load and amperage. Devil's advocate, why else would the motor run hotter if not higher average amperage? If at the edge of capability for the ESC this may well be enough to cause issues.

Although I don't know the answer to the original question. Just think it's not simple to derive from spec sheets. And even if I did I wouldn't trust the ESC ratings to directly correlate.

A sample dyno chart for reference, credit to John Stranahan.

http://www.rctech.net/forum/attachme...ss-17-5001.jpg

FWIW, the following is for a Novak 8.5 in a Stadium Truck with the pack just above nominal voltage.

http://i514.photobucket.com/albums/t...ps98f8bc23.png

Interesting ufo. What gearing were you using? Appears to be clean track running, ever take a stall reading, say from a hold the wheels slipper test or getting stuck on a pipe?

Gearing was 19/84. Don't give me credit, it was only front yard launch tests. Another motor I had was stuttering, and I was trying to get to the bottom of it. I've never done a stall test like that, mainly because I don't do the wheelie test. Although, my current ESC logs the last 12min of every single run. So, it would be easy to try. It's not a normal power configuration, but it would provide some contrast anyway.