I just brought back my small "battery maintainer" to Sears that I was using to keep my Optima Yellow charged. Exchanged it for a full-blown microprocessor controlled charger - this thing is AWESOME! $79.95 @ Sears.
It reads out the %charged of your battery, or the battery voltage. Charges very quickly.

http://www.sears.com/sr/javasr/produ...seBVCookie=Yes

Easy to use, this Fully Automatic Battery Charger/Maintainer, 80 Amp Engine Start, Battery and Alternator Tester with Reverse Hook-Up Protection for 6 and 12 volt batteries is ideal for Automotive, AGM, Gel Cell and Deep Cycle batteries. 30 Amp Rapid and 12 Amp Fast charges for Car, Truck, Marine, RV and Farm Equipment keeps you moving! The 2 Amp Slow/Maintenance is ideal for Motorcycle, ATV, Snowmobile, Lawn Tractor size batteries by providing power at all times and to keep batteries warm too. Includes:125 amp battery clamps for top and side-mount battery posts. UL listed. Three-Year Full Warranty

 

Great find. I was looking for a few for some friends down here who have dry cells.