If you want some background information on the project I'm working on, continue reading. If you just want to help then you can just skip to the bolded part. I'm supposed to build a pedal powered generator for an engineering class with a group. We are using a treadmill motor and pressing the back wheel of a bicycle against the motor so that it spins in reverse and acts as a generator. (We would have preferred to use a pulley or sprocket and chain to connect the wheel and motor for better efficiency, but time constraints did not allow this). The purpose of this pedal powered generator is to be part of a workshop with middle school aged students. We want to be able to measure the power (in watts) they produce so that we will be able to have them calculate how long they would have to pedal in order to offset how much TV they watch a day or how much they use a computer per day etc. We are able to measure voltage fine (and get up to around 150 volts ) but are having trouble measuring resistance or current. We connected a multimeter in series with the circuit and somehow the reading went over 10 amps with the motor barely spinning. I'm positive it was connected properly so maybe the multimeter is bad... I will have to try another one. This would make the most sense as I do remember getting a reading at around 2-3 amps at top speed (130-150v) when we first started this project. So since the current wasn't reading properly, I tried measuring the resistance of the motor but got something like 2500 ohms, which would put the current draw of the motor at 115v at 0.05 amps which would make sense maybe for a mouse treadmill :). So I'm guessing the multimeter is just broken? On the motor itself it says it draws something like 4 amps at 115 volts, giving a resistance of 28.75 ohms (I don't have it in front of me, so the values are just an idea). Is the resistance of a motor/generator constant, and if I run a motor in reverse will these values be affected? In other words, can we just calculate the power output (watts) using the internal resistance of the motor calculated from the current/voltage rating on the label? Or can/should we measure the resistance at rest and use this value (with a multimeter that gives a reading that makes sense :D)?