I never run out of power.
Must-have: it allows me to power up 2 batteries at the same time, and with batteries out of the GoPro. This way I can continue filming with a third batterie while these 2 are charging!
All I need to store my GoPro videos while riding and back home.
CHEAP BUT SUPER USEFUL ACCESSORIES
Those little accessories and tools are worth a look! They are cheap but sooo useful for me.