ROAD GENIE: Battery Charger, 6V, 12V, With Trickle Charge, Quick Charge, Auto Shut-Off 6v, 2A slow charge - 12v, 2A/6A quick charge; keep this in garage to charge car battery! Charge your 6v and 12v batteries in 6 to 8 hours with dual rate charger Multi-stage charging provides consistent current and less heat to prevent damage to battery Auto trickle charge mode & auto shutoff available when in 12v mode Short-circuit protection + reverse polarity protection