Hahnel's DuoPal Extra is an all-in-one mains-free battery charger and a power bank with a whopping 5200mAh capacity (three times that of an iPhone 5 battery).
The DuoPal may be used to simultaneously charge a pair of Go Pro Hero4 batteries, or to charge any USB-compatible device, such as your smartphone, camera or tablet.
And if your phone or gadget run out of juice while you're on the go, then the DuoPal can be used as a power bank - powering them directly. The unit takes 3 hours to charge a pair of Hero4 batteries, providing energy for 5 hours of recording. Mini USB to USB cable included.
Fully compatible with original Hero 4 batteries
Charge TWO Hero 4 batteries simultaneously
Internal power bank provides emergency charging on the go
Batteries fully charged in 3 hours
Mini USB to USB cable included