Generator Help


New Member
Nov 7, 2021
Hello fellow enthusiasts! I'm Nick, I'm new here. I was wondering if someone could help me with my little predicament?

I bought a 12v batter for my bike to power the lights, and I want to charge it while I'm riding. I bought a 12v generator that hooks to the magneto, and a rectifier to the battery. I need to make sure I have this hooked up correctly.

I have the red wire coming from the generator going to the yellow wire on my rectifier, red going to battery +, and green going to battery -. Is this correct or should I have the green grounded to the bike frame? I've seen other threads about this, but I can't get a straight answer.

I have attached some pictures.

Thank you for your help.



New Member
Dec 18, 2021
Yes. At least they are all supposed to work that way. Some small bikes (unlike cars) can be kick-started and run even without a battery. But all motorcycles with a battery also have a charging system. Therefore as you have stated your procedure, it seems completely fine. Nice work.


Well-Known Member
Nov 28, 2012
sf bay area
Your best bet is to get a 3s Lithium battery for an rc along with a cheap balance charger in the range of 4-10 amps. You are looking for about a 5000mah aka 5ah or bigger battery. Don’t run it under 10v. I built batteries for a living this year, including the 12v that runs my car (12v40ah 1000a peak). Just charge every 1-4 rides depending on your amp load and ride time. Way easier than figuring and messing with a charger setup. I did it with a dynohub. It worked but it sucked. Had cops flashing high beams at me when I was stopped at intersections. Didn’t charge that battery enough.