Power a Flashlight With Fewer Batteries in an Emergency




Don't let the zombie apocalypse or a power outage leave you in the dark. It's easier than you might think to keep your flashlight and other battery-operated devices running even without the proper number of batteries.

When you've finished with this instructable feel free to check out my website and YouTube channel for more how-to's, tutorials and life hacks.

My website: TheBestHobbiesBlog.com

My YouTube channel: youtube.com/TheBestHobbiesBlog

Step 1: Watch This Video!

It's only a minute long and you can watch me demonstrate every step!

Step 2: What You'll Need

This is a fairly simple instructional with minimal material requirements. After all it is for emergencies.

All you'll need is the device you'd like to power, at least one battery and some aluminum foil.

Step 3: Aluminum Foil

First you'll need to tear yourself a sheet of aluminum foil. For a flashlight that uses D batteries I got a piece about sixteen inches long.The amount of foil used doesn't have to be exact; just get as close as you can. This emergency technique will work with other battery sizes, but the amount of foil used may differ. Once you understand how it's done you'll be able to easily figure it out on your own.

Step 4: Folding the Foil

Fold your foil sheet in half the long way. Smooth it out and then fold it the long way a second time. Don't worry about super clean, smooth folds. A good-looking sheet of foil isn't necessary, and in an emergency it's unlikely you'll be taking your time.

Step 5: Size

The beauty here is that nothing needs to be exact for this to work, just close. After the folding is complete you should have a long strip of foil that is slightly taller than the battery you are using.

Step 6: Roll a Foil Tube

Now It's time to roll! Just pick an end and roll your foil strip into a tube. No need to have your tube be the exact girth of the battery, just make sure it's not too thick to fit into the flashlight and you should be good to go. You can see in the last picture that mine was a fair bit thiner and taller than the actual battery but it still worked perfectly.

Step 7: Time to Shine!

Place the actual battery in first. Follow with the foil tube in place of a second battery. Make sure everything is well situated and screw on the cap to your flashlight. If you made a tube that is slightly taller than the battery it might be a little harder to screw on the cap. Keep pushing and it will squish down to the proper height. Remember that this is going to work better than making a tube that is too short.

Step 8: What's the Verdict?

Your flashlight is now operating! It's important to note that it won't be as bright when powered this way. But it will give you enough light to be extremely helpful in an emergency. It's always better to be prepared than to need to resort to methods like this. Keep extra flashlights and batteries handy at home and in your car. That being said, if you do ever find yourself in a situation where you need to power something without the proper number of batteries, now you know how it's done!

Step 9: Thanks for Reading!

Thanks for reading my instructable! If you guys have other helpful emergency advice for myself or other readers please leave it in the comments section below, We'd love to hear from you!

Don't forget that if you'd like to see more of my videos and articles like this one, you can find the links to my website and YouTube channel in the Intro section of this instructable. Enjoy!



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    16 Discussions


    2 years ago

    I've seen things like this before. It's a cool idea.


    4 years ago

    not wanting to sound negative but
    if the foil contacts the case and + terminal, by by battery
    if too thin, it can tilt or crush becoming unusable
    my idea would be to place a smaller penlight led flashlight inside a larger flashlight capable of also holding a second set of batteries, match tube, etc (like a large 3 d cell flashlight)
    just saying you never no what or how long the emergency will be, so be prepared like the boy scouts say.


    4 years ago on Step 9

    Bravo ! Another tip for my _"the big one" (earthquake. I'm on the West Coast)_ bug-out backpack. Good info, thanks ;-)


    4 years ago on Introduction

    I may have a aluminium foil but not battery intrigues me.


    4 years ago

    Wouldn't the battery knock back and forth, slowly flattening the aluminum foil ? probably use something sturdy to reinforce the foil. Cardboard, small pipe.


    4 years ago on Introduction

    To make it even more usefull, what I like doing is permanently downgrading the bulb on a big maglite to accomodate 1 less battery than what it took initially ( a 3-battery bulb in a 4-cell lamp for example), and then replacing the missing battery with a small container containing a basic survival kit topped with a strip of aluminium tape for conductivity and sides wrapped in duct tape.

    That way you mostly loose battery lifetime, but not much brightness, and will never be caught unprepared :) .


    4 years ago

    Good idea. One question though. Can I still use the tin foil to keep my cookies from sticking to the pan?


    4 years ago on Introduction

    This probably won't work with LED flashlights as most of them require a certain amount of voltage to work, but for all the incandescent types it's a good trick to keep in mind.

    MIK3 H

    4 years ago

    Very good! Bravo bravo im going to try this out thanks! Pretty cool

    1 reply