I own this model charger and it does a great job keeping the battery in my truck (drove seldom) in fully charged form and prevents dead cells by keeping the battery charged. Not only does a battery run down when it is not constantly charged but it also dramatically shortens the life of the battery by destroying the plates within. A note of caution, when in stalling this onboard unit, it would be wise to add a inline 20 amp fuse onto the positive (red wire) of the unit just in case a short circuit develops within the unit or your vehicle. Hey, this upfront precaution is better than a fried electrical system or fire. The fuse and holder can be purchased right here on AMAZON. It would be convenient to order both at the same time plus any splicing materials etc. Make all connections tight and wrap with plastic electrical tape.