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Powering Peltier Plates Answered

Hey guys,

So, I just got a Peltier plate, a device that gets very hot on one side while very cold on the other. It requires 90 watts of power. I was just curious what would happen if you powered it by USB or 9v battery. I found this tutorial which uses USB, however, I doubt it gets to its maximum coolness potential. Also, if I used a 9v, would that drain the battery in a matter of minutes, or even damage the plate?

Thank you.



10 years ago

Okay 9v and USB are out. How would you suggest I power this? With a 12V Wall wart AC to DC converter?

nope. youd still need at least 7.5 amps to make 90 watts, and that beyond any wall warts capability's.

I'm thinking a computer PSU would be a good bet, I have a 300W and 400W sitting here, just have a question about hotwiring them, it's purple to black isn't it? But you'd get a good 12V rail, the main 12V out would provide the amperage I'd think, also connected to a couple of other projects...

purple to black will short out and blow the psu, as purple is standby power (always live 5 volts). you want green to black.

i have the same question about powering peltier module. I only have +ve and gnd wires on it. I connected it to DC power source and I keep getting a short. You guys are mentioning black, purple and yellow wires. Am I missing something in between the peltier and the power source

Green to black to turn it on, and then the 12 volt is the yellow cord. (I'm assuming you know that black is ground.)

I knew black was ground, I just wasn't sure about which one was the power on line... That was ages ago, but thanks anyway...

ITs really an amazing experience to feel cooling and heating of peltier by your own setup.

you can increase your voltage till 12-15 Volts DC. it gives no harm to peltier plate if you apply small voltage. its depend on battery capacity and Amperes per hour to get drain.

i just wanted to ask that can a peltier module work on direct current???

It makes electric current if you apply heat to the hot side, or if you apply cold to the cold side. If you give it electricity, it does the complete opposite

I am using a plate to biuld a drink cooler in my car console. For testing I am using a spare car batterry (12v). I biult a box out of a sheet of thin steel, put a plastic cooler liner inside a plastice grocery bag. I then set this in the metal box and filled the void between the two with expandable insullation (can). Thus I once the foam hardened I can remove the liner to fill it with beverages or clean it. The cooler I scavaged the liner from also had a form fitting plastic top that inserted into it to make a good seal. The top is now attached by double sided 3m tape to the hinged top to my console where it slides into the liner when closed. I sliped the Peltier Plate between a cpu heatsink with a fan and glued the solid side of the sink to the outside of the metal box. the fan potrudes through a hole in the back of my console to pull the heat out and away from the plate. On the corresponding inside of the metal box I cut out a square where the heat/cool from the plate could have greater effect on the temp inside the box. Right now I am just using a direct connection to the battery to check which is the hot/cold polarity. I plan to install a DPDT switch to control it.

My problem is that I am not getting enought temprature change from the plate. I have the two side isolated from each other as best I can by just the 4 screws holding the plate to the heat sink. Would this work better if I ran power from the batterry to 750 watt inverter to 110v power supply then it's 12v output to the plate. This makes no since to me but I am no techno whiz either.

If it's 12 volts, which I'm guessing it is as most are 12 volts, I would power it using an old computer PSU. It uses 7.5 amps, which is about half of most conventional computer PSU outputs at 12 volts.

USB is imited to 2.5 watts, rather underpowered in this application, a 9V battery, well thing of it this way 90 watts at 9 volts is 10 amps, what;s that amp hour rating for a 9 volt battery? about 250 milli-amp hours if I had to guess.

I'm trying to make a drink cooler using a Peltier and I basically have the same question. what batteries could I use to power one? I was thinking maby a 1000mAh 9.6V battery pack for R/C cars. It might work but I'm not sure.


10 years ago

Not only is a USB incapable of supplying the current you need, some USB ports don't incorporate any current limiting circuitry. So it's possible to fry the port by drawing too much current....

and seeing as your now probably wondering how much is too much, here are the figures: requested, you can draw a maximum of 500ma. unrequested, you can get 100ma

youd need to build a linear psu, but it doesnt need to be regulated at least.

I wouldn't use USB or a 9v battery to power it.

agreed, it looks like it needs a bit of umph, that neither of those can deliver