Ideal for automobiles, ATVs, boats, motorcycles, lawn mowers and jetskis, the Tender will offset the draw electronics have on your battery, even when it’s off. The Battery Tender Plus High Efficiency model operates using less electricity while producing the same amount of output, and switches from charge to float as needed to keep your battery strong all the time. The very popular Battery Tender Plus typically lists for $49.99 but is currently discounted 15% to $42.49. If dad has a recreational vehicle, this is a good consideration for Father's Day as well. See this deal on Amazon.