Watts & Amps
 

How do you work out how many Watts and Amps your motor produces/draws? Is there a formula for this?

I'm sure there is a formula, but since the motor is an AC motor and is therefore dependent on frequency, inductance, and load, it would be quite complex. Much easier to measure the current and voltage drawn from the batteries and do your calculation there. Even then, the power drawn will change dramatically based on the acceleration. A device like the eagletree systems unit takes voltage and current samples every so often (100ms IIRC) and then you can upload that to a PC to get a graph of the power usage.

Would the feigao power analyzer do the same?...

Not sure. Do you have a link to the product description?

Basically, you want a device that can measure both voltage and current samples in realtime.

Eageltree micro logger.

http://home.comcast.net/~truerc/Charge/chargers.htm

it's a feigao 100 amps power analyzer... it was cheap that's why I got it....

how you liking your eagletree... I wonder if this will die if I use more than 100 amps?..

130A peaks are not a problem.

ah.. that's cool then.... but you like the eagle tree better...