Does it have an exchangeable battery? I recently went on a four day hiking trip and switched off my phone most of the time, so that I would have power in case of an emergency. Only later did it occur to me that I could simply have packed another battery. I was thinking all complicated, solar chargers and what not.

For my digicam I have two batteries. One is always in the device, one is either in the charger or packed with the camera fully loaded. I find that works very well.