Charge Your Cellphone Using Wasted Heat (and Build a Steampunk Wall-E)

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We updated the instructable with a new implementation you can build without spending all that money on those expensive seebeck generators. This one uses Peltiers in reverse to generate rather than cool. They aren't as efficient but they are much more affordable. Plus most of the parts required are made from scrap.

Quick Jump
'''How to build a Steampunk WALL E'''

First Intro Video

Companies such as BMW are investing in Thermoelectric Generators to make their cars more efficient by replacing the alternator. Thermoelectric Generators convert wasted heat from the engine into electrical power. In this instructable we show how you can use the same technology right now at home to collect heat energy from car exhausts, waste oil burners and even our hands. We can power electronics, joule thiefs, super caps, Lego Car and anything else you can imagine.

This is our Epilog Laser Contest Entry. If you like it please vote for us.


Step 11 '''How to build a Steampunk WALL E'''

Step 6 Fire Powered Lego Car (Video)

Step 10 Thermoelectric Joule Thief (LED that lights up from oven heat)

Step 1 Whats a Seebeck? Is it different from a Peltier?

Step 2 How much power does a Seebeck generate

Step 3 Building an inefficient 5V regulator

Step 5 Thermoelectric Implementations

Step 7 More Efficient Switching Boost circuit / Info for designers

Step 8 FAQs

Just interesting Thermoelectricity from Tellurex

Stick around and learn about the the difference between peltier and seebeck units, and what electrical circuits you could use to make a green impact on our environment by utilizing wasted heat.

Keep on reading and enjoy our videos :).
- SplitReaction

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pintail12014 days ago

Dump the linear regulator - very inefficient !

get a "Bucks converter" from ebay, cheap and in excess of 90% efficient

this is is what we call
Onuigbo Loveth
please sir,detail me more on this
onuigbo loveth
criggie2 years ago
Please consider designing something to scavenge heat from a car exhaust and do something useful with it.... top up the starting battery, power the accessory circuit, etc.
haniffwahab2 years ago
i want to ask, i have try the project, but my thermogenerator have produce only 0.5v , could u give some advice how to make thermogenerator produce 3v and how about temperature and temperature ambiance?
Bold Rhino2 years ago
What kind of motor did you use? How did you build it?
J-Ri2 years ago
I think a cheaper and easier way would be to weld a flat plate to the exhaust manifold rather than use flexible TE strips. Not possible for the amateur on cast iron manifolds (which most are), but pretty easy on that steel pipe on your Mazda.

Additionally, your first thought of using the catalytic converter would be more effective (aside from possible water/dirt intrusion, but you will get some under the hood too), while not affecting the operation of it. TE modules don't cool their heat source significantly, especially when we're talking about taking a few watts out of the exhaust of something that generates kilowatts of waste heat. Heating of the cat prior to "lightoff" is the only concern. Once it reaches that temp, it gets considerably hotter. Driving down the road in a downpour doesn't cool the cat enough to lower its efficiency, even if the case is cooled to below 212ºF. Many cats have a fiber glass-like (dunno what it is) layer around the honeycomb to insulate it.
molusco5 years ago
I have a router at home wich produces loads of heat (enough to run a Stirling engine i bought). I've always wanted to do something to refrigerate it. Maybe this is a good solution to get "free" energy and cool it down. Do you think it will work?
splitreaction (author)  molusco5 years ago
Well ya won't get free energy. if you hook one of these up. Hot side to the router, cool side to a heat sink, you could generate some electricity, probably only enough to charge a small battery. Probably not enough to power another peltier cool. However if you build the joule thief from step 10 perhaps you can make it power a LED. I mean hey, it would help cool your router and perhaps add light. But man that must be a hot router.
I think he means free in the sense that he is already paying to generate the unwanted heat.

Unfortunately, you cannot cool the router and generate heat from it at the same time. If you use the power generated by the heat coming from the router to cool the router, you no longer have heat coming from the router to generate the electricity to cool the router.

For a TE module to produce voltage, there must be a temperature difference from one side to the other. This means you have two options; lower the ambient temperature or accept the increase in temperature inside the router.

Additionally, I would be EXTREMELY hesitant to use such a device to salvage energy from any electronic, and some electrical, devices. Doing so will keep more heat inside the device than what was intended, ultimately shortening the life of the device and negating any small gains.
spartans5 years ago
 hey this project is really good and i want to try it once.
hey why are these capacitors used for?
J-Ri spartans2 years ago
They are used to smooth the voltage on both sides of the regulator, and aren't really "optional-ish", you WILL get spikes over the rated voltage without them. How much over depends on a few factors, but they are cheap and you can find them anywhere, so use them.
can u please give more information about the thermal unit..
youwho2 years ago
I am wondering which peltier chip was used in this experiment. The output of the ones I have tried are very weak.

I am trying generate about 5v 3000 mA to charge a cell phone. Any suggestions on a specific peltier chip & heat sink?

what is the liquid used under the peltier?
hi i'm currently working on a project designing a portable heating lunch box that i plan to make it work on waste heat but i don't know how. any suggestions on how to power up the lunch box using waste heat?
avanner774 years ago
In her Mintyboost, Ladyada uses the LT1302 to power any USB device. After looking at the efficiency graphs, it appears to be almost 85% efficiency at 500ma. Hope this helps.

Have you thought about using it to generate hydrogen and oxygen and use in hybrid vehicle?
robcull4 years ago
say you had some warm water that you wanted to cool.
couldn't you set up a seebeck to generate electricity from the thermal energy in the water, effectively cooling the water?
I mean, I'd like be able to convert some excess heat energy into electrical energy, just to get rid of it.
likewho4 years ago
I’ve tried standard peltier modules for power generation with limited success and very short service life. They cannot hold up to the higher temperatures necessary for good power generation performance. I found a terrific supplier with both standard temperature and high temperature TEG modules designed specifically for power generation. They sell a lot of devices on eBay and you can also buy from them direct. The company is Thermal Enterprises and here is are links to a couple of their eBay items.
 we just need to get really efficient with these and attach a heat sink to the engine block and exhaust system so that we do not have a need for the alternator and we can just run the electrics in our car from that
geekchic4 years ago
Could I use a thermogenerator that's out of a propane mosquito magnet?
kdunner5 years ago
So not to rain on any parades, but this idea has been utilized for the better part of a decade. Do a google search for "heat powered fans" and see just how common this idea is. Plus, waste heat to charge your cellphones is one thing, but I hardly consider high temperature differences (eg blowtorch) 'waste' heat. Nice production, just I find it hard to believe slashdot thought it warrent of our attention.
splitreaction (author)  kdunner5 years ago
Sorry kdunner. Beserk87 was right. Just give us a chance and read the instructable you will find its not as bad as you think. I'm removing my comment in apology.
I would like to extend an olive branch, in the heat of the competition I disregarded your instructable; I felt jaded that slashdot decided to post your entry on practically the day of the voting. I hate it when people post negative things, and so I would like to apologize for not seeing the potential in your design. I would like to tell you of the potential I do see. I can see a potential marriage of our two concepts resulting in a very cool invention. My entry into the challenge is the wind power composter. The internal temperature of compost gets to 100-160 degrees F. I can imagine that if the base structure had ground penetrating prongs or just heat sinks, then a thermal momentum could be established between the composter and the ground temperature, resulting in the production of a low power source using peltier junctions. This power could turn the composter on its own. My composter uses a gear motor with a ratio of 1255:1 so a tape deck motor could potentially power the composter. I have a few peltier junctions lying around but won't have time to test the output voltage until finals are over (I really don't have time to make this post). What voltage and amperage do you think a 100-160F to 70F condition would create? If it is produces enough power, then the composter could be turned by bacteria alone, and the wind would not be needed at all. That would be a cool idea to try, after finals that is.... Again, sorry for being a troll, I want instructables to be a place of invention, creation and open ideas, and I will not let competition and self interest get in the way.
splitreaction (author)  kdunner5 years ago
My team and I were angry but not anymore. We got a lot of good comments and idea from people. A lot of members even gave us ideas. Like Kyrptonite who wanted us to try a Joule thief. We did it and it was fun. It sounds like you have a temperature delta of around 70F. This technology isn't efficient if you are burning fuel to generate the heat, but collecting waste heat is great. Even at 1% eff you are still collecting energy you otherwise would not have. I doubt the peltier junctions will be enough to generate enough power from a 70F delta. Most of the ones we see other people using don't generate that much power. They really vary depending on who makes them cause peltiers and seebecks use different metals. The peltiers we bought from PC coolers produced maybe a volt at best perhaps 6 mA(50F delta 32F (ice water) 88F human hand). That is why we purchased high end seebeck units. They are much smaller and you can tell because they are usually not sealed in ceramic. Ours generates about 5V open circuit at the same temperature where the peltier generates a weak 2V open circuit. Seebecks we bought cost around 35-80 dollars. I wonder if you could build a solar collector for your setup instead. Imagine building a parabolic mirror to reflect sunlight into a solar oven. Then placing your peltiers against the oven with some decent metal to passively cool it. you could probably even combine it with some photovoltaic cells if you have them too . You can use that to trickle charge a SLA (sealed lead acid battery). Perhaps then the stored up energy could rotate the barrel a couple of times a day. Just not the entire day. 1255:1 is an amazing gear ratio btw.
Hey guys, please send something that tells me how to assemble the microcontroller and how to connect it. Please is everything I need, I know about programming, but no how to connect the pic to the motors and peltier units. Please is for my science fair project. I would be very thankful.
no , they used a blow torch as a source of heat, for experimentation purpurses.
splitreaction (author)  kdunner5 years ago
(removed by author or community request)
he clearly didn't read any of your guide - at all. but the grammar correction is just a kick in the balls, especially since there's a spell check not 2 milimeters under the text field :P
Arshad1155 years ago
 this is one big instructable!...brilliant!..
Insidio5 years ago
Hi friends, I think I need some help. There's gonna be some cience fair in my school and I'm going to make this Wall-E for the fair. But the problem is that I don't have any legos and those wheels and lego motors. I bought some 9 volt motors, the Peltier units, and almost everything except for the pic.
So my questions are: Can I make a Wall-E with those motors or maybe using some wheels from a remote control car?Actually I have some old Tyco RC Air Rebound, I know I have to change some things in the design, there's no problem with that. And can I use a PIC16F84 instead of the Pic Kit2?
If I can use the electric car wheels and the PIC16F84 please give me some idea of how can I do it. If I can't I think I'll have to buy the Pic Kit2.
Thanks for your attention: Hugo
nachos5 years ago
 if someone one could tell me if this item would work i'd really appreciate it because i need to order it soon.

nachos nachos5 years ago
 Would The $75 dollar one on the site you recommended work as well as the one you used? the one you said you used is not there anymore.

I'd really appreciate a reply asap because I  need to order it soon.

Nice, I built on too, you can see it here. It's difficult to keep the cool side cool though!
nachos5 years ago
 will this one work?    
its a peltier

Thanx in advance

i would like to get my hands on a few of each of these for future experiments etc. Does anyone know where i can find them? Awesome but incase my question is wrong are seebeck and peltier units different products or the same product used differently if so i apologise and this question should be correct. Does anyone know where i can get my hands on some thermoelectric units like the ones in the video?
Foaly75 years ago
So, say you have an electric motorcycle, and the battery heats up from prolonged use. Could you use this to charge the battery, recycling the heat coming from the battery?
Please give any suggestion to the "Instructables the Movie" at
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