Schumacher On-Board Battery Charger
Attaches permanently to battery tray or fender well, mounting hardware included. The molded plastic sealed case is resistant to water, gasoline, oil, solvents and acids. The unit charges & maintains 12-volt batteries and is totally automatic, if the battery drops 1 volt, the charger switches on, when fully charged it switches itself off. Operates from any regular 110-volt outlet. Dimensions: 5 1/2" x 3 1/2" x 1 1/2".