How can I build a really simple electric generator & battery?
there are lots of online stores that sell small motors and generators, or check at your local hobby shop. yes, the faster you crank, the more power/voltage you will get out. It is limited by the bearings, heating in the wire, saturation in the magnet core, and voltage breakdown in the wires. Any rechargable battery will do, look online. An automobile battery is one possiblity, another is a NiCd. Be careful how you charge batteries. Overcharging can ruin a battery, and in extreme cases cause it to explode, although I doubt you can do that with manual cranking. Research the battery and battery type to determine charge rates.
