This is a great trick that could help you out in an emergency. One of the easiest ways to start a fire is to use a piece of steel wool and a 9 volt battery. All you need to do is open up the contents of the steel wool, and rub the top of the battery against the steel wool. Don’t forget to gather your kindling before doing this.
You can find steel wool in most kitchens. But who has a spare 9 volt battery lying around? Well, 9v batteries are commonly used in pocket transistor radios, smoke detectors, carbon monoxide alarms, guitar effect units, and radio-controlled vehicle controllers. They are also used as backup power to keep the time in digital clocks and alarm clocks.
This video shows how easy it is to do. Apologies in advance for the crappy background music in this video!