You never have to be stuck with an uncharged 12V battery again if you use a 1.9W, 12V Solar Trickle Charger from Koolatron to keep it fully charged. By leaving the Solar Trickle Charger connected to your 12V battery, the battery will take in as much power as it is putting out, remaining fully charged at all times. The Solar Charger comes with a 12V DC plug and battery clamps as well as 2 stainless steel screws so it can be used with several different 12V batteries.