Dolgin TC200PANBL3 Two-Position Battery Charger features two integrated battery plates supporting Panasonic and non-OEM batteries. It's capable of charging two batteries simultaneously and charges a typical 3,050 mAh battery in about 2.5 hours. As the battery is being charged, a diagnostics LCD displays status in volts, amp hours, and percentage of charge. The percentage of charge is estimated using a proprietary algorithm. An auto-detecting USB port is available for charging phones, tablets, and other USB devices; it works when the charger is plugged into AC power as well as "on-the-go" off of an attached battery.