Just like the Plus design, the Battery Tender Junior is a completely automatic battery charger using a "float" aspect which allows for it being still left hooked up into the battery terminals, charging since it depletes and only as required. Although all you must do is disconnect the battery terminals, https://hukums.com/products/stanley-stht74981-small-home-tool-kit-for-home-diy-use47-pieces-includes-screwdriver-hammer-wrench-pliers-measurement-tape-knife-magnetic-drivers-tool-box