I have heated pants and I want to get a heated jacket too. The pants take 3.8 amps (43 watts) the Jacket will need 6.7 amps (76 watts). It seems like I remember seeing something on this forum or maybe another that a monster can only handle so many extra amps. I have searched and can not find the info. If you know please respond. The heated pants I have work great! I would like assurance that my bike can handle the jacket as well as the pants before I buy the jacket.
I have a 2003 620.
According to my manual, I'm putting out 520 watts. Stock headlight is 55/60 watts, tail light is 5, panel is maybe 5? No idea what the fuel pump takes but it would seem that you should have enough.
You have a 520 watt alternator, which is rather high output for anything less than a big touring bike. At 14 volts, that would give you about 37 amps to deal with. Rounding high, 8 amps for the head light, .5 amps for the parking light, .5 amps for the tail light, .5 amps for the license plate light and another 10 amps to run the engine. Round high again and you are up to 20 amps. That leaves you 17 amps left over to run other stuff. Assuming you are running a heat troller the gear is not constantly on. What you must keep in mind is alternator output is low under 3000 RPM so keep those revs up and don't idle too long.