My ERA has had the same Optima in it since 05. I had been using an AutoMeter Maintainer. These were great since they had a short lead that could be permanently connectted to the battery. It was just long enough to hang down and be tucked up when not in use. Just this past weekend I switched to a new Optima (no good reason) and now have a similar setup for use with my Grannite Unit. These are quite good and do a number of functions including cycling your lead acid batteries. Their website is
All-In-One "Deep Cycle"