Ok, I have been reading about diodes. I was wondering if this would work. Say I cut one end of a wire and say that one end of a wire can be pluged into the wall. If I but a diode that is strong enough to hold 120volts back. Can I charge a DC battery. For Example I want to plug a plug into the wall and run it to a car battery. Is it like - |----------------diode----- aligator clamps --- dc car battery - When I split the wire can I use any of the 2 wires to connect the diode ? 120 volts is the voltage of my house at 60 hz so when I convert it to DC what is the voltage ? I would think it would vary from 0 to 120 over the 1/60 of a second?