Charge up to two GoPro Hero 3 or 4 batteries with the UGP4 USB Charger from Nitecore, powered by an external USB source. In addition to the two slots for the batteries, there is a USB charging port to further add to the versatility. The user-selectable Priority Mode lets you choose what gets charged first- the batteries or the connected USB device. An LCD screen displays real time charging status so you will always know the time to completion. When the batteries or USB devices are full, charging automatically stops. Over-charge prevention ensures continued health and proper conditioning of your valuable batteries.