Maya,
Maintainers: If your ATVs put out at least 1.5amps they should be OK.
You really need a good automatic charger too. The longer a battery is discharged the more damage is done. They "sulfate" and it is hard to undo this damage. I recommend a 20 amp smart charger. You are also going to need this to charge your house battery from your generator when camping. It will still take hours to charge, depending on how discharged it gets. You should never let them get below 12.2v (50%) discharged. More than this and they get damaged. Oh and always use deep-cycle batteries for the house. Not marine becuase they are made for both starting and deep cycle and thus are not great at either. Still a marine is better than a regular car starter battery.
I know so much to know...
