Wiring in a battery on battery-less FI bikes

Electrical Batteries

5 replies to this topic
  • yz480doinwork

Posted January 06, 2015 - 04:57 PM


I worry about the generator in my turbo YZ (snowbike). Besides the fuel injection system, it is powering my secondary injection system, Koso multi-gauge, sometimes a radiator fan, sometimes my MCX data logger and I need to get a headlight, hand warmers would be nice too. 

I would like to mount a battery and wire it into the system so I don't have to worry about my stator burning up out in the woods. Has anyone done this? I am sure the wiring cant be as simple as I am thinking. Just wire the battery into the same harness I pull the rest of my power from, and have a switch? Obviously the injection system would be live at all times when the switch was on. Would this cause any problems? I also wonder if the battery would be at risk of over charging when I'm not using a bunch of juice? Electricians, I need your help!


  • grayracer513

Posted January 07, 2015 - 07:29 AM


Are you currently running everything off the stock AC system?  No rectifier, etc?

  • yz480doinwork

Posted January 07, 2015 - 08:45 AM


I should have mentioned this is a 2012 model. So everything is spliced into the stock DC system, via baja designs harness.

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  • grayracer513

Posted January 07, 2015 - 09:35 AM


Does make a difference.  That system actually has over 100w of DC power available already.  But, there shouldn't be a reason that you can't install a battery.  Naturally, it has to live only on the DC side of the rectifier.  You can simply tie it into most any point at which you have a red lead (DC 12V+) in the harness, but best will likely be to add a 16ga lead at the rectifier/reg and run a ground to the frame or to the common ground the circuit uses.  The battery needs to be of a type that's safely rechargeable, such as a lead/acid or a properly packaged (including a controller card) LiFe, etc.

  • yz480doinwork

Posted January 07, 2015 - 10:57 AM


I wasn't aware that the yz system put out so many watts. I just hear horror stories about burnt out stators leaving guys stranded in the hills. When set up as a dune bike, the bike temporarily dies for a split second when I switch on my two fans. I wonder if a battery would cure that, I can't imagine that is too good for the system. I didn't figure the wiring would be quite that simple, I have heard talk of having to use diodes and other components. If I do try this out, I will just grab the battery out of my WR to start with.

  • grayracer513

Posted January 07, 2015 - 01:28 PM


The thing is that the EFI YZF's already have a complete AC to DC system set up, so all the diodes and whatnot are there.

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