How to Start a Fire with a Flashlight

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One of the most important survival skills is knowing how to start a fire in the wilderness.

It’s best to know multiple firestarting methods because you may lose tools, not have access to certain materials, or otherwise have to adapt to plans gone awry.

I’ve also pointed out before that a flashlight is an excellent addition to your everyday carry kit.

A flashlight can not only light up your life but it can also be used defensively.

Did you know that you can also light a fire with some flashlights?

Let’s find out how!

Three Flashlight Firestarting Methods

There are three main flashlight fire-starting techniques.

Not all of these can be performed with every flashlight so you will want to practice all of them at home before you need to rely on the skill in the field.

That advice applies to every skill, by the way.

Practice with your tools!

The first method is to use the sun’s energy to light a fire by using the flashlight’s reflector as a mirror.

The second technique is to short out the flashlight’s battery, producing sparks.

The third way you can start a fire using a flashlight is to burn the tinder with the light itself!

Let’s look at these three techniques in detail.

With the Reflector

Capturing the sun’s energy with a mirror to start a fire is a time-honored technique.

Many kids have practice doing this with a magnifying glass.

You can start a fire with almost any mirrored surface, from a polished brass plate to, yes, a flashlight’s reflector dish.

The idea is to concentrate the sun’s rays onto one point. This directs all of that incoming energy into a small area, heating it past the material’s ignition point.

However, the most reliable method for starting a fire with a flashlight using the sun requires that you can remove that shiny reflector from the flashlight’s body.

You find these more commonly with single-bulb flashlights. Those work best. And tend to be higher-quality anyway.

They take the light from that one bulb and cast it over a wide area. We’re going to do the opposite!

How to Start a Fire with a Flashlight Reflector

In order to start a fire this way, you need to have a flashlight, some tinder, and enough light from the sun.

Disassemble the flashlight and remove the reflector. We don’t need the rest of the flashlight.

Next, take some of your tinder and put it into the hole at the base of the reflector.

You want some sticking into the reflector. Not too much, mind you.

Then, angle the reflector toward the sun so as much light is concentrated on the tinder as possible.

If there’s enough light in the sky, your tinder will shortly catch fire!

With the Battery

This fire-starting method uses the battery stored within your flashlight.

The idea is to close a circuit between the positive and negative battery ends using a piece of metal.

As the metal you use isn’t going to be a good conductor, there will be a lot of waste heat, igniting the metal and tinder.

You can do this with foil (a foil gum wrapper works great).

Another option is to use steel wool and 9-volt battery. If your flashlight uses a different type of battery then you’ll need some wire.

How to Short a Flashlight Battery with Foil

What we want to do with the flashlight’s battery is to send some electric current through a resistant piece of metal to catch it on fire then spread that fire to your tinder.

Foil, especially the paper-backed pieces of foil that covers gum sticks, works great for this.

You’ll need to slice the gum wrapper into thirds to form strips that are wide enough to fully contact the positive and negative ends of the battery.

Then, cut the foil into an hourglass shape so the current has to flow through a chokepoint. That’s where the fire will ignite.

Hold both ends of the foil tightly against both ends of the battery, with the foil touching the battery.

The center portion will quickly burst into flames so you’ll only have a few seconds to use it to ignite tinder!

How to Light Steel Wool on Fire with a Flashlight Battery

A more reliable method for starting a fire with a flashlight battery is to burn steel wool.

If your flashlight uses 9-volt batteries then you can just touch the ends to the steel wool and ignite it, then use the burning metal to ignite tinder.

However, most flashlights use tubular batteries.

Holding steel wool against both ends would likely result in igniting the steel wool under your fingertips. Let’s avoid that!

So, you’ll need two pieces of wire.

Connect one to the positive end of the battery and the other to the negative end. Depending on your flashlight, you may be able to do this without removing the batteries!

Then, touch the non-connected wires to the steel wool (not each other!)

This will set the steel wool alight, which you can then use to start your fire.

With the Bright Light

The two techniques above require disassembling the flashlight or attaching wires.

What if we could start a fire by doing nothing more than turning on the light?

It’s possible!

…if you have a bright enough flashlight.

That’s because any source of light will produce waste heat. Even LEDs1.

Fire comes from fuel plus oxygen plus heat, so a bright enough light will produce enough heat to ignite tinder.

Some tactical flashlights, like the Klarus XT11GT, have a turbo mode that kicks up the brightness to the maximum for a short time.

Those extra-power modes are limited because they produce a lot of waste heat. Let’s use that heat!

How to Burn Tinder with a Flashlight

In order to start a fire with a flashlight using the light alone, you’ll need a super-powerful flashlight.

The brighter the light, the more waste light, the faster you’ll ignite the tinder (and the farther away you can do so).

I’ve seen weak ignition from weaker lights but you’ll want a flashlight capable of putting out at least 2,000 lumens.

All you need to do is to turn on the flashlight and shine it at your tinder, real close to the tinder.

It’ll heat the fuel until the material reaches the ignition point.

Boom, fire from a flashlight!


Everyone should keep a flashlight or several in your EDC kit or bugout bag.

Light sources are useful for finding your way, blinding attackers, and, yes, even starting fires.

The biggest piece of advice I’d like to give you is to practice with these firestarting techniques while you’re still in the safety of your home.

Shivering in the cold is not the time to learn that you cannot remove your flashlight’s reflector!

Also, this will allow you to see if you can store some firestarting materials inside your flashlight.

You can sometimes stuff a gum wrapper, some steel wool and wires, or even some homemade tinder into a cavity in your flashlight.

Why not take advantage of that extra space?

What do you think? Have you ever lit a fire using a flashlight?


Can a Phone Flashlight Start a Fire?

Smartphone flashlights are too weak to start a fire on their own.

If you’re in a dire situation, however, you can disassemble the phone and use its battery to start a fire!

How Many Lumens Does it Take to Start a Fire?

Lumens are a measure of visible light2, not heat or power, so there’s no simple measure for how many lumens it takes to start a fire. However, all flashlights produce heat as well.

The weakest flashlight I’ve seen start a fire put out just over 1,000 lumens, but it took a long time.

The more lumens, the more waste heat, the better the flashlight’s fire starting capability.



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