12v dc car bat on a peltier/ tec, keeps blowing out, wat do i need 2 make it work?

hey guys, i'm running a 168w tec of a 12v dc car battery that i want to turn into a in car fridge/drink cooler and i want it to run of a 12v connection off a car battery. the two tec's that i bought died(aka not working at all) after i connected it off a 12v dc car battery. what resistors, etc do i need to make it run on 12v and not down it to a lower voltage? also how would the answer differ if i wanted to upgrade to a 400w tec? appreciated ;P cheers -dan

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Dan_J (author) 9 years ago
hahaha, i think that might have been my problem, didnt think it cud pass the kill temp in under 30 sec's as i was just testing them with out a heatsink, the heat sink i'm using now is kinda chunky, raided it out of a water cooler . the base is 5mm and fins are 15mm. was thinking of making a heat sink out of layers of copper sheet metal i'll get another one in, strap the heat sink on it and see how it goes thanks guys
Big Bwana Dan_J9 years ago
Oh ya those TEC's can get very hot in 30 seconds, just try powering one up and put your finger on the hot side, unhook it when you can't hold on.... Heavy Aluminum heat sinks are the way to go, they can be found at most surplus shops and talk to a metal recycler in your area they may have huge heat sinks from motor speed controllers, industrial electronics and most will sell them for metal weight, which is a steal if you price them from new...... (( I just picked up a 8 x 12 and it's base is 1inch think and the fins are about 3 inch's and it was $20, they didn't even weight it, they asked me what I was doing with it, I said it's for a school project for the kids, he said are you paying cash, I said yep, he said $20 and we both left happy... )) And while the computer ones are fairly effective, most Processors don't even come close to outputting the amount of heat a 168W TEC does If your going to build your own get a thick plate don't use multiple plates, even a very small defection in one plate and you will bust the TEC and or crush one of the junctions, effectively busting it, on several coolers I have taken apart they use a solid block of aluminum about 3/4 inch think the size of the TEC and then this is attached to the thinner heat sink,while maintaining a think base, this also allows for more insulation from the hot to cold side.....
Big Bwana9 years ago
What size heatsink are you using on the TEC, and more importantly what is the thickness of the heatsinks base, the base thickness is a commonly overlooked thing when dealing with TEC's, huge TEC's like a 168 watt's will over heat, melt there solder joints and fail with out proper cooling, and a huge TEC like that need no controls if you driving it right off a battery, it does need cooling...... (( now I have had some luck heating defective TEC's with a heat gun, and reflowing the solder and I have gotten a few working again so you might want to try it, but only use enough heat to reflow the solder, or you will damage the TEC, and the solder is very low temp specialty type )) And why are you using such a huge one, most travel coolers use a 48 watt tec, a 168 will kill a car battery, so you will have trouble starting your car in an hour, and a 400 watt is some where in the area of 10 / 15 mins.....
You're probably putting way too much current in to them, what are the ratings for them, apart from wattage? You could use a different power supply, car batteries are great at giving lots of power but their ability to supply current is a double edged sword...
Dan_J (author) 9 years ago
thnx for the quick reply Operates from 0-16 volts DC and 0-10.5 amps