Portable USB batteries are great, but what happens if they run out of power? That is where FlameStower comes in. Instead of having to use a portable battery, the heat from your campfire is converted into electricity to power your electronics. You just slide the FlameStower into your fire, and your phone or camera will charge. It outputs 2.5 Watts, so it can charge an iPhone completely in about 3 hours.

I'll be picking one of these up in the spring for camping season. Check out their website for a better look at how it works. Even if you don't intend to use it on every trip, it's a good backup in case of emergency. One minute of charging will get you enough power for a two minute phone call.

Buy it on Amazon for $89.99.