Certain batteries, AGM type are designed for use in Solar banks. I use Chairman/Concorde/SunSaver. I have used these in my solar cell sites for over 12 years now, some may even be longer. I use a 255 amp hour battery in my trailer, with a Morningstar 15amp Digital controller, 100 watt panel from Home Depot. All this runs through a Progressive Dynamics brain box, that distributes 110 with breaker, 12 12 volt fused lines. It is a smart device in that it charges the batteries on quick charge if needed, slow charge and converting 110 to 12 volt, so no battery use while plugged in to shore power or generator. It also maintains batteries in storage. My set up, other than the battery is very reasonable, for top of the line equipment.
You can read about them here..
http://www.sunxtender.com/series.php?id=3
These batteries burry all others I have tried, including Odyssey, Optima, Die Hard, any Marine battery. Optima was the rage just before we found these. I normally ran 12 group 31 batteries in a tower. The Optima's would last two years, with continuous maintenance. Cleaning them every month, checking ouput, system noise. Concored/Chairman/Sun Extender units have lasted triple the time with far less maintenance/concern. I have towers that have never been down due to solar in over 12 years using this type of battery.
Old sarge put his trailer away for the winter, 4 months it ran the fridge, turned on. It was down in the 10 volt area. How long no one knows. Hooked a charger to it and it is holding a normal charge. That is pretty amazing. Nothing like them on the market. They are used in military jet fighters supposedly. But under no circumstance would I call them economical, but you get what you pay for, well with Optima you don't.