Available Excess Amperage?

[ShortCourse]

Looking to add an inverter to charge one or possibly two M18 Milwaukee batteries. Standard charger appears to be around 360 watts.

I've tried searching to see what "leftover" amperage is available on a stock 180amp alternator, but not having much luck. I understand that when you have a trailer hooked up with all the lights on and the heated seats running and heated steering wheel and all the bells and whistles you pretty much max out the alternator, but I'm not sure what the more day-to-day average draw is.

I'd like to use a 500w inverter (roughly 42 amps).

Anyone have any experience?

 

[Travelin Ram]

No worries. I use an air compressor that draws 90 amps, nearly every day. Sometimes with the HVAC and headlights on, no problem.

500w is NBD.