On Fri, 09 Nov 2012 14:59:07 -0500, wrote:

Just make sure you make the decision to leave town BEFORE you burn
out your 100 amp alternator by running it at over 50% for more than
half an hour.

Need more numbers. Figure winter time driving A/C defrost on, heater
fan on high, headlights on, parking and sidelights on, rear window
defroster on, radio cranked up, fuel pump and ignition running.
Pretty sure that's more than 50 amps, or close.
I do it every winter for hours at a time. For years on the same alt.
Of course I would have to measure actual amp draw on my car.
Anyway, I low-balled the 120v output at 500 watts, and figuring
inverter loss into it that's still less than 50 amps from the alt.
I've read that a typical alt puts out 60% of rated amps at idle.
If I ever set up an inverter I'd measure draws. You can burn up your
alt if you want to. But you don't have to, and I don't fall for scare
tactics without numbers backing them up.