Kharn wrote:RV plug or jumper cables would give you 20-40 amps, which would reduce your charging time significantly, plus avoiding the losses in the inverter and charger.
Probably not if you use any wire smaller than a #8 awg. Voltage drop is brutal at 12V. I had to run #6awg wire from the battery to my hitch to get 13V at 5 amps to the trailer battery. Granted, my truck is a lot longer than most vehicles but it's still hard to get anything near 10 amps with the size wire that most people use.
Also, the average car alternator isn't going to put out anywhere near it's rated output at idle speeds...
Bruce