Yup. We use 6v golf cart batteries. Never found anything that beats them as far as availability, size, charging characteristics and total lifetime. We typically get 6-8 years out of them but we have had a few last as long as 14 years. When they get a bit weak I move them to the "b" circuit which is an isolated system for back-up lighting only, and we get a few more years out of them.
The Trojan T-105 has proven to be the best bang for the buck in this type of battery. Big enough to be useful, small enough that we don't need block & tackle to move them in & out of the basement.