Re: White wire charging power?
You will need a rectifying circuit (very easy 4 diodes, google for a pic). Its 6volt . I wired a big halogen spotlight with built in battery to mine and ended up losing spark, make sure you add a switch to turn the charge circuit off if needed to isolate problems. I have seen the photo's on here that show the white and blue wires aren't connected and they made sense, but that was my experience.
hope this helps