Charge from your sweat

But, if you're in a pinch, it's nighttime, and your solar charger hasn't seen the sun in a while, that's where good old-fashioned elbow grease comes in handy. Hand-crank chargers like the Slive-88 make an obnoxious sound and they take a lot of effort to make just a little power. Still, you can't go wrong having one of these in an emergency. If you can find one like this that integrates a radio and a flashlight, all the better.