The Duo LCD Battery Charger II from Watson charges 1 or 2 batteries of various types via dedicated interchangeable plates, which are required and available separately. The Duo Charger can simultaneously charge 2 different battery types with different voltages. It runs on 100-240 VAC power, allowing for use all over the world. The charger also features a USB 2.0 port for charging another device simultaneously. The LCD screen provides a digital read-out of each battery's charge percentage while charging and can also show a battery's charge status via the battery test button, even when the charger is unplugged. Integrated detection circuits protect batteries from overheating while charging by automatically stopping the charging process, and also guard against dangers such as defective batteries or short circuits. The Duo includes a power cord with a 2-prong US plug, as well as a 12 VDC car charger that plugs into a cigarette lighter.