The more I think about this the more I think using car batteries for this is a tad dangerous, sealed, old-school with caps, no spill batteries, etc no matter the type/style. Chemically created energy in a thin walled box is not to be played with, particularly when it sits ideal a lot. When in a car they are 'exercised' regularly. Sitting in the situation described here they will be doing nothing. Much like dry-cells, I have seen car batteries that experience a chemical breakdown when they just sit.
BUT if you are going to .... I'd build an outside and well vented box on posts (though given size and extra gear you might need some of 'shed' size), made of wood on a solid base that would have in it one (or more) of those Rubbermaid(TM) style non-metallic storage containers for the battery(ies) to sit in. I would keep a dedicated trickle charger handy in the box/shed to be hooked up to each/the battery after it is brought into use and had a drain put on. As soon as power was restored it would easily be hooked up to get a recharge. Don't keep a dedicated charge in the battery area and you won't find one when you need to use one. That would be due to Mr. Murphy BTW. I don't think this would work, but the ideal situation would have the trickle charge hooked up to the battery all the time. I am not sure how that would react with the 12v dc-dc atx adaptors. IF the charger >> battery >> atx adapter could be in a chain, you'd have a nearly set and forget setup. EXCEPT FOR ... given my first paragraph. if anyone implements a set up like this it should be eye-balled and maintained very, very regularly. Also I'd really be interested in photos of a working arrangement. RbtBotL Craig - ><> o BU SysAdmin /|\ 607 777 6827 ^ Tot Ziens -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]