Batteries and Steel Wool Fire from steel wool and a battery Like the chocolate and soda can method, it’s hard to imagine a situation where you won’t have matches, but you will have some batteries and some steel wool. But hey, you never know. And it’s quite easy and fun to try at home. Stretch out the Steel Wool. You want it to be about 6 inches long and a ½ inch wide. Rub the battery on the steel wool. Hold the steel wool in one hand and the battery in the other. Any battery will do, but 9 volt batteries work best. Rub the side of the battery with the “contacts” on the wool. The wool will begin to glow and burn. Gently blow on it. Transfer the burning wool to your tinder nest. The wool’s flame will extinguish quickly, so don’t waste any time.