Attracted by the price, disappointed when I needed to use it. The charger seems to work: when the original battery is inserted the light is orange, when the 2 Smatree batteries are installed, the light is green. The problem is when I put the batteries in the Smatree Gopro 4 Silver, nothing passe.J'ai tried to load with GoPro and still nothing (no red light to tell it load). Tried to charge with the charger on PC and nothing more. So back to the supplier and to refund me.