Gopro technology

My activities last sometimes 7 hours. Even longer. My Gopro battery lasts for 2 hours so I use external power bank that lasts for much more than 10 hours. I have my camera on my head and the charging cable is from the camera on my head to the power bank in my jersey. To be able to charge while I do my activities I take the usb door off the video camera. This works great until it rains. In rain I need to put the door on the camera again to make it water proof. So when it rains I need to use the internal battery as much as I can and not using the power bank. And when I am out of power I put another internal battery in the camera.