I have a set of AGM batteries from Cabelas and they are awesome. They didn't cost much more than regular batteries and they don't need any maintenance and can take the pounding lead-acid batteries can't. I have 2 group 24's and 2 group 27's and they run my ac overnight off an inverter. If you go to cabelas.com they even have packages for 2 batteries and an automatic charger, and the shipping is very reasonable. I highly recommend them.