Remote power options for small guitar amp

Hello! I'm possibly going to be playing for several evenings at a campsite this summer where there is no power source. Has anyone ever tried using a power inverter connected directly to a (spare) car battery? I don't need to blow anybody's doors off, but I'm hoping to play for 2-3 hours for several nights at a moderate volume (just loud enough to be heard over a drummer). Would this work? Are there any better options short of a generator (which I want to avoid due to the fumes)? Thanks all!