Lithium-Ion Dual Charging Dock for Nintendo Wii Remote 2 High capacity Lithium-ion Rechargeable battery packs. Lithium-ion batteries provide twice the playing time and twice the battery life span compared to Ni-Mh batteries. Low self-discharge rate. Charge up to 2 Wii-motes simultaneously. Charge through the USB port on the back of the Wii system or any other USB device. LED indicator lights up when charging Wii-motes.