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Smartphone Charger Powered by Fire

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Portable, Compact and Adjustable ThermoElectric Emergency Generator.


Background:
The reason for this project was to solve a problem I have. I sometimes do several days of hiking/backpacking in the wild and I always bring a smartphone with GPS and maybe other electronics. They need electricity and I have used spare batteries and solar chargers to keep them running. The sun in Sweden is not very reliable. When you need it as most it´s either raining or other circumstances that makes it impossible to charge with solar panels. Even when it´s clear weather it simply take too long to charge. Batteries are good but heavy. I have looked for alternatives but they are either very expensive or too large. 

One thing that I always bring with me though on a hiking is fire in some form, usually an alcohol or gas burner. If not that, then at least a fire steel to make my own fire. With that in mind, I got stuck by the idea of producing electricity from heat. I know, the efficiency is very poor but it is at least possible! So, with inspiration from my previous project (Thermoelectric-Fan-Driven-by-a-Candle) I decided to build my own thermoelectric charger. There are similar projects available but not that fulfill my requirements (what I could find).

Concept:
I´m using a thermoelectic module, also called peltier element, TEC or TEG. You have one hot side and one cold. The temperature difference in the module will start producing electricity. The physical concept when you use it as a generator it's called the Seebeck effect. Thermoelectic modules are mainly used for the opposite effect, the Peltier effect. Then you apply a electric load and it will force a heat transfer from one side to the other. Often used in smaller refrigerators and coolers. Read more about i here:
http://en.wikipedia.org/wiki/Thermoelectric_effect

My requirements:
  • As small, light and portable as possible
  • Robust
  • Adjustable voltage (want to use with broad range of products)
  • At least 5V/0.2A (1W) to charge an iPhone 4s, 2W if possible
  • Compatible with alcohol/gas burner, campfire and candles
Solution:
With lots of testing and experimenting I come to the conclusion I would need a powerful TEG-module. I have previously used a cheap TEC-module (8€) but it only produce about 0.5W and too low voltage and max temperature. I could use several of them but it will be a more complicated and heat limited construction. I found a 40x40mm TEG that produce 5.9W (4.2V/1.4A) at 180ºC difference. It has a maximum operating temp of 350ºC (180ºC cold side), that should be enough. It´s quite expensive though, about 50€ but that is still cheaper than most solar chargers and much cheaper than other commercial thermoelectric chargers I found.

To transport away all heat and cool it with air you usually need a large heat sink. As my construction need to be compact and light weight, I was thereby limited to very small heat sinks. I then decided to "steel" a small amount of electricity and cool the construction with a motor/fan. That would result in less charging energy but that was the only thing I could think of to keep the size down (and not using water cooling). As it gets warmer, it produce more electricity and also more cooling power from the fan. To block heat from transferring to the cold side I used two heat insulated washers for the fixating and also a layer of insulation between the metal blocks.

First priority was to get a steady 5V source to drive different USB-devices. The module itself produce less than 5V. I solved that by constructing an adjustable regulated voltage Step-up. The detailed specifications can be found later in this project.

Result:
When I started this project I had no idea it would actually work. It turned out it even works over my expectations! I can charge my iPhone which was the main goal and it is completely self-cooled even with extreme heat sources.
The cooling is not optimal due to it´s small size, but I´m quite satisfied because I can bring it with me. I would happily see you construct even better solutions, I´m absolutely certain it could be made even cheaper and more efficient. There is a lot waste heat in this construction!

To actually make this yourself, keep reading! More testing and results in the end.

Features:
  • Adjustable output voltage
  • Adjustable RPM of cooling fan
  • Adjustable temperature monitor
  • Adjustable voltage limiter
  • Adjustable construction height
  • Optional USB-connector
  • Easy to assemble/disassemble
  • 400g
  • 90x90x80mm

Applications:
This can be used with a broad range of heat sources and power a broad range of products.
  • Candles (low output power)
  • Spirit burner/stove (hard to control)
  • Gas burner/stove (best so far)
  • Wood stove (not yet tested)
  • Camp fire (not yet tested)
  • Metal can with fire (not yet tested)
  • Barbecue (not yet tested)
  • Light in the dark (LEDs)
  • USB charger (Phones, batteries, etc.)
  • External fan (cooling effect, fire booster, etc.)
  • USB-gadgets (music player, drink cooler, etc.)
  • Charge super capacitor and power high intensity SOS signals

Donations:
High effect thermoelectric modules are expensive. If you would like to see more of those experiments in the future, please consider a small donation.
Bitcoin address: 1BouwowuprgQrtUYgyzYnNvHyRYbLceqHg
 
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1-40 of 96Next »
berkanice16 days ago

Hi, I liked your charger much! Congratulations. I have some questions, I'm glad if you answer :)
1- I want to charge phones as you do but my idea is to connect 15-20 pieces of TEGs in series. Because I want to use a 35-40 degree celcius heat source and continuous flowing air as cold side (15-20 degrees) Would it be enough for charging phone with USB?

2- I read that cold side of TEG become hotter due to incapability of cooling side. So the efficiency decreases by time, then, how long charging lasts?

Joohansson (author)  berkanice16 days ago
Thank you! Unfortunately I can't help you with that question.
borgassa2ky2 months ago

Quick question, what if you were to construct a miniature oven for a briquette (BBQ coal). Would this produce too much heat? Or would it even be effective if only using 2 or three at a time?

I am in the process of constructing your design now, and am also trying to design groves on the bottom heat plate that could slide onto a 90X90X90 mm metal "Oven" or holding container for the coals.

Let me know if you have any ideas or have already tested this theory.

Joohansson (author)  borgassa2ky2 months ago
I think it can work. I was going to try that but I'm afraid that the heat will be too hard to control and damage my prototype. It could be that too much heat rises from the oven and make it impossible to cool the upper heat sink. A gas flame is very concentrated if you compare. But if you try it, I would like to see it!

You can also try to cool with water instead of a fan, that is easier to control and never exceeds 100 C. That would have greater probability of success.
Kristy luo3 months ago

Even i am a seller from China but i didn't know clear how it works. I will learn here, and if you don't mind help me when need, thanks in advanced.

scottdave3 months ago

Looks like a great project. I may have to try something similar - one day when I have time :) It inspires me though.

good day. i just wanna ask where country did u bought your module? thanks

Joohansson (author)  patricia_philippnes5 months ago
Hi, bought in Sweden.

ok..thanks. is it ok if i replace pt1000 by PT100.. can there be a difference? :)

Joohansson (author)  patricia_philippnes5 months ago

Yes, if you also change R3 to 100ohm instead of 1000.

zubair0015 months ago

Hi, sorry for the late reply. Hope you are good.

I got the two thermocouples and the voltage booster delivered only today, so started conducting some crude tests with it. The results are a bit sad actually. I know this is not how its supposed to be done but just was too eager and wanted to see what I could generate with a simple setup. So what the picture shows is two of the previously specified thermocouples connected in series and on a hot plate. and both sides covered with wet tissue and no wind blowing over it. with fan assisted cooling it generated about 0.3v max and stabilized at around 0.25v. So my voltage booster didn't work. I don't know how much more i can i can get it to generate after sandwiching it between aluminium plates and repeating the process. If I consider the above tests valid I would need a total of 8 TECs. I couldn't measure any current when connecting my phone in the circuit which draws 650ma. I probably have to get me some resistor I guess. How do you suppose I can measure the current output ? And can you make any wild guesses on how much current it can give me on a 8 module series setup. Thanks.. :D

Test1 chilled water glass.jpgTest2 Table fan.jpg
Joohansson (author)  zubair0015 months ago
I suggest you first learn how the booster works. It probably need a certain voltage just to start up. Maybe you have an adjustable power supply you can experiment with? All TECs works differently, they give a certain voltage and current with a certain load at a certain temp difference. You get maxium effect when your load perfectly maches the specification of your TEC. The phone is also tricky because it needs a certain voltage just to start charging and the current it will draw depends on the input voltage. I think the easiest way to measure current vs. voltage is to attach different resistors (1-100 ohm) to your TEC and measure current and voltage at the same time. Another critical part is your TEC contact surfaces. Whatever you are cooling and heating with it must make perfect contact. I used professional thermal paste, without that it will probably end up damaged, and maybe you have already damaged your modules. I also like trial and error but please read some more about this or you will just be disappointed.
zubair0015 months ago

Hi, Joohansson. I am incredibly impressed by your skills and projects. I am not good with electronics but would really like to try this out. But I have a very limited knowledge of electronics and a fairly modest budget. So i am using the following things:

1.) A 12v 0.2A computer fan with heat sink (Hope to run it at lower voltages)

2.) 0.9v to 5 v DC-DC step up regulator (it says 700mA max output current)

http://dx.com/p/usb-dc-0-9-5v-to-dc-5v-voltage-ste...

3.) 2 X TEG modules specified as:

Type number: TEC1-12709
Couples: 127
Umax (V): 15.2V
I max (A): 9A
Tmax (degree Celsius): 67
Dimensions: 40mm x 40mm x 3.5mm
Power cable: 32cm
Max. power consumption: 136.8W

I selected the above as I read in a research report that TECs compared to TEGs are more efficient for power generation at lower temps. Also higher the V X I rating of a TEC, the higher you can generate power off of them.

I know 67degC is not much but i hope to cool the other side enough (maybe 30C).

I plan to connect them in parallel to increase the amps. Maybe connect one more in parallel. (My sink is rectangular so 3 would fit under it.) I have to arrange a multimeter.

I need a simple to understand circuit i can make with ready-made parts that will fit together and supply a limited power to the fan and give most of the hard earned amps to my usb charger with some safety so I don't blow up my dear old galaxy S2 :-)

I'm a proper newbie so any help or guidance will be much appreciated. Thanks, Zubair001 :-)

Joohansson (author)  zubair0015 months ago
Thank you! Nice too see you trying this. I'm not an expert either, most of it was trial and error but I was lucky with very few errors. I think you have two problems. A 12V fan running at max 5V might not give you enough air flow too cool it down. It is the starting up that it the most dangerous part because you need much power very fast. If you heat ot up slowly the fan will never start and the module will get same temp on both sides which then give you zero power. The other problem is that 67C is very low indeed. You have a high risk of destroying them.

I would suggest you to start cooling with water since it much more efficient, to see that everything works as exspected. But even water will reach 67C pretty fast.

I hope you solve it, good luck!

Thanks for replying. I think you are right about the fan not starting so i will probably buy this

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&it...

after I try out the available one when the rest of the parts arrive.

Second I'm still hoping to use just the heat sink to do the job but I may have to use water cooling as a last resort. As far as water exceeding 67C and blowing up the modules, i plan to use the drip and sponge method (I call it that ;-) ). Imagine a soaked tissue spread over the cold side and constantly replenished with drops of water as it evaporates. And if the modules still want to blow, well then I don't have any other use for them.

Maybe without the use of water, the temperature might not drop too low. But just how low it needs to be to generate enough voltage and current is one thing I will know only after testing it out. For I am going to use not one but two or maybe even four in parallel or series or series-parallel.

Now if I have a 5v fan, a heat sink, some TEC modules and a 0.9v to 5v DC-DC step up voltage regulator, what else do I need to complete the circuit so that I give only the rated power to the fan and no more (not sure if it'll be good giving it more) and the rest of it to charge the phone.???

I know you did all your circuits using the very basic components but you know I'm really not gifted in electronics like you :-) and really don't understand much about electronic circuits so I would rather buy complete circuits if they're available rather than do the calibrating, fabricating and soldering things to make more mistakes than maybe I'm already making.

Thanks!!!.

Joohansson (author)  zubair0015 months ago
Ok, that might work. You need to regulate the voltage to not exceed 5v. I could not find a good circuit for it, that was the reason I built it my self. You could technically use just a zener diode (zener diode voltage regulator) but it will flow too much current through it. I used a high effect mosfet transistor to short-circuit voltages over 5v and a simple operational amplifier to control it. I used the zener diode to control the amplifier. But I understand it could be a bit tricky if you have no experience. The solution is not very pretty either as it burns energy instead of use it. The pretty solution would be to use a buck-boost converter or a SEPIC.
http://en.wikipedia.org/wiki/Single-ended_primary-inductor_converter

It would regulate both <5v and >5v. I have not managed to find a really good one but I actually bought this one to experiment with for future projects (search ebay for buck boost if link has expired):
http://www.ebay.com/itm/3-15V-To-0-5-30V-Auto-DC-DC-Solar-Converter-Regulator-Boost-Buck-Module-25W-New-/141150576527?pt=LH_DefaultDomain_0&hash=item20dd3adf8f

It will regulate 3-15V input To 0.5-30V output. I didn´t like it because you needed 3V as minimum but i think that could work for you if you have for example two TEGs in serie.
you've got a nice project.. is your project for sale? please reply soon. thank u. :)
Joohansson (author)  patricia_philippnes6 months ago
Thanks! No, not for sale.
okay..thanks again. :)
Joohansson (author) 7 months ago
If you want a cheap 5W thermoelectric module, back up this project for $19! I ordered one myself =)
http://www.kickstarter.com/projects/david-toledo/the-powerpot-x-most-reliable-10-watt-portable-gene?ref=live
thebeave06307 months ago
What about the material they use to make the seals around oven doors to use as an insulator between the sides? You might have to cut strips because of the diameter but it can withstand very high temps for long periods. Sorry if that was posted already, I didn't read all the comments.
Joohansson (author)  thebeave06307 months ago
That might be a good idea to try! Thanks.
Nihal1 year ago
Great project, but reminded me of this: http://www.biolitestove.com/
Granted, it costs an equivalent of 100€ instead of the 80€ you spent, but it incorporates a nice stove as well and provides 2W at 5V. Maybe you could draw some inspiration from it to improve your project.
ITS REALLY GOOD SUCCESSFULL PROJECT,
BUT TO BE FRANK I FELT FUNNY BY SEEING YOUR HARD WORK
and so much of money which u spent to produce a small voltage..
there was alot of alternatives for this, i must talk to you, please give me ur mail id
i share my thoughts, even i know a process to charge mobile battery by tree leaves..
Joohansson (author)  graghavendra1 year ago
What can I say, I like to build stuff:) I can admit I did not explore all alternatives before i did this, but I don't regret it at all!

Please tell me your thought how to charge an iPhone in the wild since that is my main concern. I'll send my mail to you.
Any word on the tree leaves? I'm interested.
Joohansson (author)  caleb.gross1 year ago
No, we only discussed solar panels.
this site gone mad, or my browser gone mad.. i tried alot to reply. but fail to do it
used crome, mozilla, still fail. site has some problem
anyway, posted reply above.. please see it, any info just ask me
best solution for rich people is.. amorphous panels.. buy 20watt panel.
coversion is heavy 19%. just half kg, keep inside bag. take it where ever u want. get ur charge, atleast it produce 5W which required to charge in non-summer season also..
1. amorphous solar panels. which are light weight to carry..
300grams can produce equal energy to charge 3 mobiles at a time.....

2. flexible solar panel/PET/glass panel (frame less) buy it in large quantity prepare like bag as i made (see pics).. which is really affordable than all these..

3. dynamo. for same struggle u r suffering by this can give 1A charge can be produced for iphone.

4. battery bank, recent days these hitting industry like hell..
10000mah batteries just 30$ (wholesale price) buy few charge it
all can give this suggestion, what is speciality of me? here is my special
buy few anti-radiation stickers (quantum energy sticker/scalar energy) just 1$ each buy 5, patch it front back of batteries, .. batteries can charge 30% faster.'

as the present technology which reached buyer, these are the above solution affordable than you machine. :)

all photos are attached here.
amorphous solar panels, PET, cabinet, solar charger bag,
all these are really afforadable compared to any other..
these are reason make you these very high cost
1. brand 2. design 3. not required accessories 4. location (if u buy in UK,US,EU always costly these are rich country, so cost also more)
sp-1.jpg1283933691673_hz-cnmyalibaba-web3_49486.jpg575925943_725.jpg562695222_227.jpg454615504_571.jpg519732999_65.jpgIMG_20130502_154902.jpgIMG_20130502_110343.jpgIMG_20130502_154913.jpgsolar panel in hand.JPGSolar-Cell-Charger-Size-in-.jpgSolar-Cell-Charger-Size.jpgSolar-Cell4V-Size.jpgIMG_20130606_113456.jpgIMG_20130606_113446.jpgIMG_20130606_113437.jpg
it was akeshia leaves, they can store electrical charge..
someone charged their battery by those leaves in few secounds..
need more research on this. but i m not sure how to do it
ctien11 year ago
i was thinking of methane microturbine generator for use in country that have no electrical grid. this may work as a power source from using animal/plant waste that produce methane in a large container, the methane comes out and lite as a heat source, on top of the flame there will be your thermoeletric generator. there need to be a big one build as in a big one that can power a small home. its something to think about.
ArsenioDev1 year ago
this is awesome! great job!
Elipsit1 year ago
Hey I really like the idea, well done!
I recently built a candle powered flashlight last year using a smaller scaled version of what you've done and am planning to try for a bigger setup.
Have you seen these Step Up Boost Modules:
http://dx.com/p/usb-dc-1-5v-to-dc-5v-voltage-step-up-boost-module-green-143571
and
http://dx.com/p/usb-dc-3v-to-5v-voltage-step-up-boost-module-red-146765

They are only $3-4, much cheaper than actually having the boards made haha.

Cheers!
Joohansson (author)  Elipsit1 year ago
Cool, that is some kind of joule thief I think, probably very low efficiency. I bought a similar one for just $1 from China but it is not very good.
very cool, maybe on your next version you could try to use SMD components there not hard to solder as you may think with some good and careful placement and solder paste can be done very easy, i also recommend trying a different fan such as the fans for laptops some of these are 5v and provide high airflow at low power, also a copper heat sink would be better as it has a faster response time to dissipate heat.
Can't wait to see your next version Keep up the good work.
jgeorge141 year ago
I have some issues with your comments. First off, the Battery packs I have are a lot smaller than that contraption you have. Second of all, you should put your phone in airplane mode or shut if off when in the woods due to poor signalling capabilities in those areas usually. The phone searching for signal is the worst battery killer there is. I knwo this from riding motorcycles in the country. We'd keep it in airplane mode, and turn the signal on when we stopped for eating or gas to check up on things back home. Battery would last for 2 days easily doing that. Plus, all it takes is one component on yours to fail and your out completely of the recharge source. With a trusted and proven and tested battery backup, I would bet dollars to donuts that it would be much more reliable, oh, and its not that heavy, less than a pound and it recharges my phone 2 times from dead. I like your idea, dont get me wrong, jsut your example and application are not sufficient. A zombie apocalypse would suit this device just fine though!
First off he uses an iphone they have bad reception compared to other phones anyway so saying that i am sure the user knows about the reception problems and thus would not take a Iphony in bad reception area's, the other point Peltia's are a proven tech just like Solar Panels or Stirling Engines to provide power for different applications where an Grid power maybe a problem, thus this person has provided a tutorial on what is possible more so then, plus another person has told you that most phones now days have other functions such as GPS or maybe used as a map or compass, in this situation cellular towers are not needed.
Battery Packs only last so long especially on a iphone due to the fact of its poor construction and old engineering that Apple constantly uses in there products so next time have a think and maybe some research before ripping on someones instructable.
I have the Asus Padfone 2 16 hour talk time 36 hour talk time when docked in pad mode, why the main proc is 28nm thus saving power while keeping the same speed from the testing i have done this is the fastest phone on the market with long battery and good reception and cost about the same, found by Research...........
Joohansson (author)  jgeorge141 year ago
I agree what you say, but if you use gps tracking the phone is empty in half a day. If you are away for one week, that means 14 recharges and a lot of batteries. If you can power the phone by using only wood, then you only need to bring my 400 grams and a lighter. This is only a prototype, I would not bring this with me as my only hope until it´s robust enough to trust.
Wait so help me understand, why do you have heat sink connected to the cold side of your heat-electricity-maker-thing? Thanks!
Joohansson (author)  FoamboardRC1 year ago
If it is not cooled, it would not be a "cold side" and it would not produce any electricity. There must exist a temperature difference over the module and the heat sink uses surrounding air to transport away heat.
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