Candle-Powered Electric Candle




About: My name is Randy and I am a Community Manager in these here parts. In a previous life I had founded and run the Instructables Design Studio (RIP) @ Autodesk's Pier 9 Technology Center. I'm also the author ...

After seeing news reports about Hurricane Sandy and hearing the ordeal that all of my family and friends in New York and New Jersey went through, it got me thinking about my own emergency preparedness. San Francisco - after all - sits atop some very active fault lines. As local geology fans always like to point out - statistically speaking - we are long overdue for a large quake.

This forecast is bad news for me, because I don't think that I am very prepared. I might have a few gallons of bottled water in the back closet, but I was ordered not to look in there until after Christmas... so... I am really not sure. Hopefully we will not have an earthquake before then. Anyhow, in the meantime, I have no real emergency supplies to speak of.

I have been thinking a lot lately about being more prepared, and what supplies we should have on hand for when the 'big one' hits. After prioritizing the three most obvious things to have in a severe emergency - water, food, and a fair-sized crowbar - it came down to figuring out what else one needs to survive. It did not take me very long to conclude this item was electric lighting. I use that all the time. How can I live without that?

After assessing the problem, it became apparent to me that after a few days of constant lighting, all of my batteries will be dead. This means that either I need rechargeable batteries, or a way to generate electricity without them. Not needing batteries to begin with seemed most sensible to me. I explored different options and finally figured out a low-cost, long-term, and portable, method to keep my electric candles lit.  I am going to use heat generated by tea lights. The nice thing about this solution is that they are dirt cheap, small, and will last forever. You can buy about 1,000,000 tea lights at Ikea for $1.99. With a fair-sized stock of small candles, I can keep my electric candle lit indefinitely. Thanks to my candle-powered electric candle, I know that I will never be left in the dark.

Do not leave this contraption unattended. Always have a fire extinguisher on-hand. This is probably less than ideal for normal day-to-day use.

Step 1: Go Get Stuff

You will need:

(x1) electric candle
(x1) Peltier heat sink assembly
(x4) 12" x 3/16" aluminum rod
(x4) 3/16" shaft collars
(x1) candle

Step 2: Drill

Drill 3/16" holes in the corners of the larger "cool" heat sink. This is the heat sink that gets cold when electricity is applies to the module.

Make certain that the 3/16" rod will be able to be inserted through the hole, between the grooves, and out the other end.

Step 3: Attach Shaft Collars

Slide the shaft collars about 3" to 4" up the aluminum rod and fasten them into place.

Step 4: Assemble

Slide the aluminum rods through each of the corner holes, such that the heat sink is resting on the shaft collars, and the cool heat sink is facing up.

Adjust the height of the shaft collars until the bottom "hot" heat sink is elevated high enough off the table to allow you to place a candle comfortably underneath with about an inch of clearance (for the flame).

Trim away the excess aluminum rod material, such that all four are flush with the top of the "cool" heat sink.

Step 5: Wire It Up

Connect the red wire from the peltier junction to the positive terminal on the candle. This is the terminal the little nipple on the battery normally touches.

Connect the black wire, the ground terminals where the flat side of the battery normally connects.

Step 6: Insulate

Apply electrical tape (or insulator of choice) over each connection. This will keep the circuit from shorting out on the heat sink.

Step 7: Cover the Sensor

Take a small piece of tissue and jam it into the candle's light sensor hole. This will make the candle believe it is always night time, and not wait until it is dark to turn on.

Step 8: Fire!

Light your candle and place it below the "hot" heat sink. In a few minutes, the electric candle should light.

Adding an extra candle should speed up the amount of time it takes to glow.

If you blow out the candles, the electric candle will stay light until the heat sink cools off.

Do not leave this contraption unattended. Always have a fire extinguisher on-hand. This is probably less than ideal for normal day-to-day use.



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    119 Discussions


    10 months ago

    Very nice idea and very good out of the box thinking. Take some wasted heat and turn it in electricity. It may not be the most efficient application, but neither using an arduino to turn on a led, is. Both are a very good starting points for thought and new ideas.

    1 reply

    3 years ago

    i'm in search for a peltier module to power a led light for cooking on a rocket stove, i shop at conrad for my Electronic stuff but there a lot of different models to choose from..

    1 reply

    Reply 2 years ago

    Look for a Seebeck module. Like a Peltier but optimized for generating power instead of generating heat and cold temperature differentials.


    2 years ago

    This is really a stroke of genius!

    I love it.

    Marvin Minsky (the inventor of the machine that does nothing but turn itself off every time it is turned on) would be proud!


    6 years ago on Introduction

    you could have the bottom made with a solid copper plate so it is a heat absorber and not a dissipator. If solid it can be placed on a heat source and absorb heat faster. Here is something similar

    3 replies

    Reply 5 years ago on Introduction

    If I remember right, a good absorber is the same thing as a good dissipator. So the heat sink which dissipates heat well should do an equally good job of absorbing it.


    Reply 4 years ago on Introduction

    Absorber/Dissipator are not quite the same in my comprehension (though the/my terminology might be wrong)

    Absorber would be referring to how well heat is transferred into the material, as in its thermal conductivity.

    Dissipation ability would be how easily it looses heat. This can be improved/worsened (depending on your point of view) by altering the thermal mass (how much material is present) and how much surface area is exposed to air/moving air.

    This is why a tin lid works better for the hotside than a heatsink despite differing thermal qualities. The tin lid, has little thermal mass and sucks at dissipating heat under load (although looses it very easily due to its low thermal mass). On the other hand, the heatsink has a buttload of thermal mass compared to the tin lid, the reason the heatsink is not good though, is because, even under high-ish load, it can loose heat to the atmosphere far easier than the tin lid because of the emense amount of surface area which is arranged in a way that is able to "leak" heat to the atmosphere.

    As such a lump of copper plate would prob cut the bread as would a tin lid. Copper would be better though or alternatively a moderately thick piece of metal such as aluminium, tin or steel.


    Reply 4 years ago on Introduction

    And here is a bonus tidbit :)

    Not only do you have to concern yourself with thermal losses via convection (air stealing and mollesting your precious heat), but you also get radiative losses (i.e. heat loss due to thermal radiation in the infrared spectrum).

    Whilst in my experiments making this do something very useful are not very fruitful thus far... I know it's been done successfully. NASA has a probe out there somewhere that is using a depleted uranium heatsource and the bone chilling cold of space via a thermo-electric cooler. It produces some voltage (i don't remember :$) and around 200-300 watts. Whilst that is a buttload of power, remember that the hotside is prob 40-60C maybe cooler, maybe hotter and the cold side is around -250C or lower.


    5 years ago

    Hey, aren't you the guy that designed the gas engine that generates electric power for the Chevy Volt?


    5 years ago on Step 3

    Why didn't I think of that? Excellent and simple idea; props to you sir. I'm going to start on mine after this post!


    5 years ago on Step 8

    that is a great idea,how much electricity does it generate?


    Reply 5 years ago on Introduction

    Congratulations, that's almost as cool as the Pixies thing.

    Also I've been wondering what that thing is on your desk. Now I know it's a recursive redundancy machine.

    those black card bits of humor between ads that show up, telling you random bits of current events. they mentioned an electric candle powered by a real one while they were browsing the internet.


    5 years ago on Introduction

    cool or hot even.nice one, but now confusing the fan sealed on both sinks? or is there a pass through for air,doesnt look like it,my intuition says it dont work,but it clearly does. imagining convection currents of air going round in circles what goes up must come down. am presuming its a regular motor fan.tempted to make one sure it would work but how! i think i have a similar heatsink from a mini fridge in the shed somewhere buried, its december and its old out there.let me know so i can get on with this 35 to medium format camera conversion.

    2 replies

    Reply 5 years ago on Introduction

    What looks like a brushless fan between the two heatsinks is actually the Peltier, or TEC module surrounded by black foam weatherstripping insulation. The module is what generates electric current when there is a temperature difference between the two sides. These modules will also heat up on one side and get cold on the other when electric current is applied to them.