The BatteryMINDer 12 Volt OnBoard battery restorer / conditioner stores lost power and doubles the life of all types and sizes of 12V batteries while on the go. Patented high frequency &Quot;random sweep&Quot; pulses safely dissolve sulfate, the main cause of early battery failure. Restores lost power and doubles the life of all 12V batteries High frequency &Quot;random sweep&Quot; pulses safely Built-in battery and alternator condition tester with voltage surge protector Easy 2-wire connection to battery terminals Watertight Safe for use with all types of vehicles and will not affect electronics or computers Handles up to 4 parallel-connected batteries