Of course, the first thing that comes to your mind when it comes to making fires is to use a magnifying glass or a curved glass, or even a polished spoon – when you have sunshine you can start a fire using almost any kind of light-reflecting surface. But what if it is nighttime? What if you are in a very dense forest and the light is very dim, or the sunshine can’t get through the dense canopy? Then you might need to search your pockets!
An incredible way to start a fire using a battery
Let’s say you have found a regular battery in one of your pockets. Any type will do – AA, AAA, C or the big D size of battery – it doesn’t matter. You’re halfway through already, now you need to find a stick of a gum in your other pocket. Or a pack of cigarettes. Or, at least a bar of chocolate – any item, that contains aluminum foil in its package. Ideally, you want a 2-layer material, where foil is the upper layer, and the bottom layer is paper. However, pure foil will also do, you’ll just have less comfort with it.
Also, you will need a knife, but even if you don’t have it, you can just carefully tear it even without a sharp blade. So, first of all, get a stripe wide enough from the foil (nearly 1,5 cm wide).
The length should be enough to touch both sides of the battery (+ and – ). And then make a narrow bridge in the middle of the stripe, nearly 2mm wide.
And that’s almost it. Find an even surface, put something easily inflammable to use for tinder (like dry moss, if you’re in the woods), and “wrap” this material around the narrow “bridge” of the foil stripe.
For example, wrap a piece of cotton wool around a candlewick.
If you have a regular (pure) foil, this method will work again, but you will have to wait longer – until the heated foil sets the moss or cotton wool directly on fire.
How is this possible
The trick here is simple. When you press the foil stripe to the “+” and “–“ of the battery, this causes a short circuit. The many times amplified current starts running through the metal foil, which makes the foil heat. In the thinnest place, that is, on the 2mm bridge, the heat is big enough to make the metal red-hot and set the paper layer on fire.
If you decide to perform this experiment at home, you may want to “fluff” the upper layer of the cotton wool a little bit, for better flammability. Be careful: the sides of the battery become hot during the experiment – watch out for burns. So, stay safe with the batteries!