Instructables

Thermoelectric USB charger - off grid electricity.

FeaturedContest WinnerContest Winner
Picture of Thermoelectric USB charger - off grid electricity.
This strange looking pan is a device to generate power from a low temperature heat source. By using the seebeck effect, it is able to produce enough electricity to charge a cell phone and other USB devices. The best part about this contraption is that it has no moving parts.

The device has a nimh power pack which stores electrical energy for use whenever you need it, the power pack can be detached for use anywhere. The output is 5V through a USB port. This device would work especially well were there is snow available for extra cooling – for example off grid cabins in remote (snowy) locations. It could serve as dual purpose - melting snow for water and producing electricity ? The bigger the temperature difference between the two sides of the peltier the greater the power output.

This idea is not new, it has been around for a long time. See here for some very
old thermoelectric generators

The peltiers produce 0.6W of power to recharge the battery pack.

If you like this, please vote for me in the Off Grid challenge. Click here to view the contest.

Here's what you'll need :



Video  guide to making the pan :


 
 
Remove these adsRemove these ads by Signing Up

Step 1: Tools and materials

What you'll need :

Materials
  •  
  • 2 x TEC-12706 Peltier Modules
  • DC-DC USB Step Up converter
  • Small switch
  • Project box
  • Small scrap of vero board
  • 4 x 3000mah nimh/ni-cd batteries
  • 1N4001 diode.
  • Battery holders for the batteries
  • Miscellaneous wire, solder etc.
  • Thermal compound
  • Aluminium or copper milk pan
  • PC CPU Heatsink
  • 4 M4 x 12 bolts
  • 4 Long (>75 mm) M6 bolts for the feet
  • Electrical connectors (screw terminal type)
  • Silicone tubing.

Tools:
  • Drill & drill bits
  • Multimeter
  • M4 Tap
  • Soldering iron
  • Files
  • Screwdrivers
  • Spanners to suit the bolts


Notes: The PC heat-sink must be big enough for the two peltiers to sit on.
I bought the DC-DC converter on ebay, it has an integral USB port.
1-40 of 46Next »
Cambenora1 year ago
Excellent instructable. It's good to see Peltier cells being used in this way.
scraptopower (author)  Cambenora1 year ago
Thanks.
HarshB8 months ago
This is a excellent instructable! I was wondering however, do we need to use 2 heatsinks; one in the bottom of the pot, and one in the inside? Or just one in the bottom. Appreciate the help.
hai,
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?
hai,
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?
mlove81 year ago
hi
keegancdr1 year ago
this doesnt charge an iphone.... :( what a waste of money ...
check this: http://www.ladyada.net/make/mintyboost/icharge.html
I used a different step up converter and it works just fine
scraptopower (author)  keegancdr1 year ago
Apple like to annoy everyone by making things that only work with apple. There is a way to make it charge, by adding some resistors somewhere. Have a look on Google for apple usb charger schematic or something similar.
DevonJM1 year ago
There is one severely flawed aspect to this design you have shown, you NEVER put your screw points at a diagonal to your tec components, so never at the corners, only along the sides or else the compression will interfere and break the modules in far shorter time span than they are spec'd for. Change that, and its perfect.
poofrabbit1 year ago
Hey congratulations on being a finalist in the hack it contest! Good luck to you!
keegancdr1 year ago
i got all my parts in today! i am confused as to where to soldier in the diode. could you show me a picture of the whole wiring layed out without the 3.5mm jack in there? i just need to see a picture . thanks alot! :)
I have a question, If you used a more powerful peltier element for the thermoelectric charger, would you get a larger power output? If it would, then would it be more efficient to use more small peltier elements, or to use one big peltier element?
keegancdr1 year ago
is this the step up dc-dc converter you used?

http://www.ebay.com/itm/USB-DC-DC-Converter-3V-to-5V-1A-Adjustable-Step-up-Boost-Power-Supply-Module-/150897682187?pt=LH_DefaultDomain_0&hash=item232233e70b#ht_4631wt_1417
scraptopower (author)  keegancdr1 year ago
Yep, that's the one.
Thanks a lot! Another question if I were camping could I leave this contraption running all night? Or untill the candles went out? Or is there a time limit to how long I can run it? I'm wondering for like leaving my phone plugged in and charging over night ( in a fire safe environment )
If you were worried about the candles being left overnight, you could try boiling up some water and replacing the candle with this heated water. Cooling 3 pints of water from 100 degrees to 15 degrees involves roughly the same amount of energy transfer as burning one of those candles would, so if you had a big enough campfire to boil a large amount of water during the day it could be something to consider.
So, (1)how hot does the thing need to get? Would it work well on top of say, a wood stove, if left or (2) does the water "have" to stay cool?

nice guide, cheers!
scraptopower (author)  rrepass jr.1 year ago
It needs a temp difference of around 80 - 120 centigrade to charge. The water doesn't have to stay cool. It seems to hold steady at around 40c after a few hours running so not really cool. But the cooler you can keep the top the better. A little tower with cloths resting part way in the water would probably help cool it by evaporation.

I think it would work quite well on top of a woodstove, though it might possibly be too hot.
they make fans for woodstoves with a copper base and heat transfer bar, then the fan motor and cool side radiating fins up top, used to spread the heat of a woodstove around a cabin or other similar thing. Ecofan is oen of them.....expensive of course, as is the biolite thing.
I have seen stirling motors with fans that do the same, without electricity. Make one!!
Yeah, stringstretcher, I was thinking the same, but have you seen any designs here... def want to not buy, but build ;)
Stirling build designs are all over the internet. I have made some using plans like this. They ran off of a stove quite well, but when I place one on the grill the solder joints melted! Lots of fun to build, and if you find a use for one, even better!
Gadget931 year ago
This would be great to use inside my Infinite Improbability Drive. I use a nice hot cup of tea to power it though.
HHGTTG some of my most read books =)
agis681 year ago
anonther one for school project!....now iam try to find the pot....lol
naplatki1 year ago
Super idea on constructing final loader. I thank very
tkamsker1 year ago
I was building the same and did connect it with the http://www.bootstrapsolar.com
kit ,.. but can you explain me why you need this hughe heat sink ? Is there an tecnical reason for that ,..
Would be nice because ill then build it fitting for canteenkit
thx
thomas
scraptopower (author)  tkamsker1 year ago
Not really, I just thought it would help collect the heat better. It does need to be kept cool on the cold side tohough, which can be hard to do in a small space.
This was so great, scraptopower! I loved it, faved it, and voted for it :) And am going to give it a shot soon. I have a thought, about developing it further so as to possibly use a composting box as a power source, with all the heat developed by biological activity? Say, in a greenhouse? 'Twould be a good use, what say you to the idea and its feasibility?
Regards,
Aiden :)
FJMSoft1 year ago
I'm thinking... if put another pan in the other way? With the opening for down side...
Vincent 7520: there is a stove online called the BIOLITE Stove. Has a USB charger built on the side of a backpacking stove, weights around 25g boils ware in less than 15 minutes. Quite the little deal.caa
lornfate1 year ago
Very useful! Thanks for the share...
Cool Instructable! Actually the mars rover Curiosity uses a similar device to power itself. The only difference is Curiosity uses heat from uranium as a heat source, but it still goes through a thermoelectric module to generate power.
I think they used Plutonium (mucho calor!).
sdobbie1 year ago
*pan
very neat … 
congratulations

now is there any way the whole thing can be made smaller in order to carry it when backpacking or other outdoors activities ?

congratulations again ! :)
NightLord1 year ago
Have you tried if it worked without heatsink on the bottom?
scraptopower (author)  NightLord1 year ago
It will work but it can damage the peliters becuase you get more hot spots and uneven heating.
1-40 of 46Next »