The charger works fine even with the supplied power supplies for 12V socket and has one thought along the same and 2 USB sockets provided. So you can, for example, still load the phone with or the GoPro also operate for charging. Very good!
The batteries themselves are minimally worse than the original battery (maybe 5-10 minutes less recording time) with me at runtime. But that falls on only when remeasuring! I can not say anything yet, wait times as long do the over the behavior after many charging cycles.
Conclusion: Super-thought that one set each GoPro 4 User can only recommend, therefore 5 Stars.
Addendum 27.12.2014:
After less than 5 cycles has a battery completely given up the ghost. He can no longer store the Gopro does not start and a multimeter displays 0V voltage at - so totally defective - let's see how long the other by holding and what the complaint brings - as long as the assessment is revised to 3 stars