The latest rage in battery chargers seems to be ones that can do desulphation. There is a lot of discussion about how injection of a high frequency a/c signal into a charging current can revive failed batteries.
I have not been able to try this myself (but may have my home back soon) but a friend had had good luck reviving golf cart batteries.
The reason I mention this now is because apparently Big Lots acquired a large supply of Vector 1097A-M "Smart" battery chargers that include desulphation capability. It is solid state and quite light with 2/10/30 charging and 80A starting capacity. I bought one for $39 and is SKU 220012891.
If you look these up on the web they go for $85-$95 (list $107) and the -M means this is the marine version with conformal coated circuit boards and nickel plated clamps. This one also has selection for flooded, gel, and mat batteries.
If you are not familiar with Vector, they were bought by Black and Decker (which has the same charger in different packaging) and is owned by DeWalt.
If you have a nearby Big Lots it might be worth giving them a call.
See
http://www.brandsplace.com/0371-vec1097a-m.html