Batteryminder Charger/Maintainer/Tester/Desulfater - 12v, Model# 2012 Fully automatic plug & run charger/maintainer/desulfater/tester for 12v batteries Patented full-time pulse-type desulfation keeps battery free of sulfate or dissolves sulfate completely in older batteries Recovers weak or deeply discharged batteries: sealed and filler-cap lead-acid batteries. (AGM-type batteries, including Optima, Odyssey, Interstate and Exide require charger). Includes reverse polarity protection, thermal runaway protection, au Battery tester and recharger prolonging battery life!