Thanks for all the replies. I wasn't planning on changing out the 12 volt ones that I have at this time. I was just thinking about the future and whether it would be advantageous to do the change. If I could get more "life" out of the 6 volts, it might be worth it. I'm not electrically inclined, so I would have someone hook them up for me so I don't blow up everything connected to the batteries. But, that's for the future. Right now we can dry camp without hookups for about five days before having to use the generator to bring them back up to charge.