BlueTech Dual Battery Charger for GoPro HERO4 BLACK, SILVER, Music, Surf Edition: (GoPro AHBBP-401 Replacement) Mini rapid charger fully charges 1 or 2 batteries for the GoPro HERO4 Great replacement for GoPro AHBBP-401 Smart charging LED indicates when charging is complete and prevents battery from overcharging charges well... red means charging and green means done. This dual battery charger allows you to charge two batteries for GoPro HERO4 at a time.