This battery tester is designed for permanent installation in the vehicle. It does not require continuous power and only displays five different battery charge states (full, still okay, charging or driving, empty charging, must charge - battery sulfated) after pressing a button. This allows for a quick check of the charge status at any time to determine the need for a battery charge. The electronics are waterproof and can be flexibly mounted on the frame or handlebars of the vehicle using the included cable ties.