If you can adjust the output of your charger, then it should work okay. I use a small Honda eg650 powering an Iota 30 smart charger to charge a group 27 battery(two on board). The Honda 1000 inverter generators are even quieter(I'd go with the 2000 though....). Works good, lasts a long time. Generator comes in handy for venetian night also...;-) I can actually start a 5000 btu air conditioner with the 650......provided I do it stages...low fan, compressor,high fan...draws 400 watts. I can charge the car battery with the 12 vdc output, but takes too long....
http://www.youtube.com/watch?v=G5pzfZ1SFzo
http://www.youtube.com/watch?v=G5pzfZ1SFzo