At 7 amps max output it is better than some but it seems ridiculously overpriced to me. It really is more a Maintainer than a charger. For other battery maintainers check out these brands;
http://www.batterytender.com/ http://www.batteryminders.com/...e.php In my opinion the BEST reasonably priced battery charger;
http://www.blackanddecker.com/....aspx $85 here; http://www.boatandrvaccessorie...D.htm The Vector 1093 DBD has desulfation, equalization, up to 40 amp charge, and 100 amp starting mode. It also has separate settings for AGM, flooded, and Gel batteries. Unless you wear it out or it fails, it should be the last charger you ever need.