i understand that i can not use a 12 volt light because the amount of wattage would greatly exceed the output of the generator. my generator is only 6 volt AC 3 watts or 4.5volts DC. i think i might try the 17 watt one. i have lots of rechargeable AAA batteries from my remote control cars and i don't want to spend too much money on a light for my bikes that i get for free.