The eCycle 100 amp controllers I use on my scooters regen up to 50 amps back into the battery and work down to 1 volt coming out of the motor windings. I can push the scooter at 3mph and get 100 watts into the batteries at 36-40 volts at 3 amps. No other controller on the market works this well. And does it ever slow you down quickly!