Sharkk 2 Pack Battery for GoPro Hero 4 2PK and Dual Charger for Go Pro Hero4 High Capacity Batteries with High Speed Rapid Charger AHDBT-401 AHBBP-401 2 LITHIUM-ION BATTERIES  Includes 2 rechargeable lithium-ion batteries, dual dock charger and USB charging cable. DUAL DOCK CHARGER  The dual dock charger allows you to charge 2 GoPro batteries simultaneously so you can always keep the camera rolling. OVERCHARGE PROTECTION TECHNOLOGY  LED indicator lights inform you when the batteries are fully charged and ready for use. The overcharge protection technology makes sure you do not overcharge your batteries or damage them from excessive heat that can be caused during charging. COMPATIBILITY  The batteries and charger are only compatible with GoPro Hero4 cameras. The included standard USB charging cable works with any 110V wall outlet, USB car port or computer.