Using Batteries to Start Fires in Seconds
Steel wool is highly conductive and tends to flame and smolder when ignited. All you need to do is press both terminals of a 9 Volt battery against a piece of the wool to start a small fire. You can easily transfer it to paper or other tinder to build up the flame. You can also use the wool as the base layer of a fire as well.
You can start a fire with jumper cables, the battery in your vehicle and a pencil in a matter of seconds. Whittle away two separate inch wide chunks of wood on the top half of the pencil so that the gouges extend until you reach the lead in the center. Clip each terminal of the jumper cables to one of the notches in the pencil and squeeze firmly. Place the pencil and cables atop a bed of dried grass, hay or paper mixed with kindling at the base of your fire. Connect the cables to the battery of the vehicle and watch the pencil begin to smolder and smoke as it ignites the material. You may need to move the pencil into a better position as the smoldering grows, but make sure to do so by holding the rubber part of the cables in order to avoid getting burned or shocked.
Paper Clip or Staple
You can start a fire with a cell battery, such as a AA, AAA, C or D by making a minor modification and attaching a paper clip to the negative terminal. The first step is to pry off a portion of the outer cap of the terminal and insert the end of the paperclip or staple so that it contacts the cell beneath. Push down on the pried end to hold it in place when finished. The trick is to take some paper or steel wool and use it to press the free end of the staple or paperclip against the outside of the terminal. A fire will start to smolder once the material, metal and battery all make contact. The great thing about this trick is that you can use any size battery as long as you have good material for tinder.
Foil or Gum Wrapper
Another really simple fire starting trick is to attach foil or a gum wrapper to a battery. Simply attach one end of the material to the top and other end to the bottom of the battery and press. It will start to smolder and quickly flame up before extinguishing. You need to make sure that you can place the battery next to a wad of paper or some dried grass or hay so that it will ignite the material before the metal foil burns off.
Try these tricks out for yourself to get a feel for how to position everything to minimize wasted energy while starting the fire. You will quickly discover that this is a great reason to always have some extra batteries handy. You can even use one from your flashlight or other device to get the job done if you are ever in a pinch.