I'm going to be using heated gear and a Zumo. Im trying to figure out how many watts I have left over for running electrical accessories. I understand my charging system total output is around 540 watts, how much of these watts is needed to keep its own system charged. thanks

 

The FLH alternators on '07 and above are rated at 50A, so at 13.2V you've got 660W to play with. The only limitation you may see is the 15A limit (fused) on the ACC plug, if you use that source, but you could wire directly to the battery and fuse it for more. I have a heated liner and gloves and together they use about 10A, so I doubt if you'll hit the 15A threshold unless you start adding pant liner and/or socks to the mix.

As for how much load you can put on the system to keep the battery charged, I don't know--but I assume it would be the rating of the alternator. That said, I would figure on the low side, for 12V, which would be 600W. Anyone know for sure?

 

Thanks, looks like I will need 134 watts and 11 amps for my accessories, I would assume I have enough extra watts even at idle???

 

Your presumtion would be correct. I have electrical gear for two plus the zumo and have know issues. Just remember do not turn on your electrical gear without the bike running and turn it off before you turn off the bike. This is according to Gerbing for the protection of the electrical gear (no sudden surges) and no drain on the battery.