Good competition with the original batteries

The Smatree batteries are for about 3 weeks at me in my GoPro Hero 4 Black Edition in action.
I have therefore done everything possible by night time lapse over 2.7K @ 60 shots in freezing temperatures, up to 240fps slow motion.
Mainly the battery is inserted in my skiing. There I usually in a "high-performance" mode filmed (2.7K@60). So I took all three batteries (2 Smatree + Original GoPro battery) every day. The GoPro Battery mean very quickly succumbed to the low temperatures (-5 ° to -15 °). The pre-cooled Smatree batteries have shown plugged directly into the camera after only 2 of 3 battery bars. But they have just as long if not longer than the GoPro held Battiere.
The charger I have found to be very practical. The 2A USB port is great to still invite z. B. a cell phone or the GoPro with the original battery. The possibility to connect the charger directly into the wall socket, prevents unnecessary clutter (which is very handy on vacation).
However, I can make no statement about the long-term performance on the batteries.

All in all, a very good and especially cheap alternative to the original GoPro batteries Smatree batteries. And the charger is well thought out.