Therefore you need a 12V 18Ah battery. It shouldn't be too difficult to do the research and find the lightest/most cost effective charger?

A Li-Ion laptop battery is pretty close to that. They are cheap because of volume. Investigate available "standard" Li-Ion laptop battery amp-hour ratings and form factors.

 

Ahhhh - the laws of physics: completely irrelevant to those who don't understand them.

And every Marketing Director I had the misfortune of encountering in my 30 year career as a power designer.

 

First..."16000mAhr" is only 16A, Ahhh, marketing! With the cooler, once things cool down they pretty much stay that way. Only heat added is due to the inefficiencies of the insulation and seals. The Peltier then does not run full time, only enough for makeup. Your project involves a person that is continuously generating heat. Takes a lot more power to cool a person than a small box of cold beer. Maybe they could just periodically drink the cold beer out of the box.

Ken

 

A battery "AHr rating" is based on a current draw of AHr/10Hr. An 18AHr battery is rated at that based on a 1.8A continuous draw for 10Hr. You would need a much larger battery to continuously draw 6A for 3Hr and have many charge cycles. Probably something more like a 50-100AHr deep discharge marine battery.

Ken

Yes, the reason for this disparity between 1.8a for 10hrs and 18a for one hr is the peukert effect. I think the rule of thumb is something like "double the rated discharge amps, half the capacity". LiPo batteries are much less susceptible. They have "C" ratings Which are the factor you can multiply the discharge amps by. Search for turnigy lipo brick.
But they aren't really safe to strap to your body

 

I know that some UAV companies use very thin light-weight Lithium Ion batteries that can supply at least 4vdc per unit. 6 of these units at 24vdc last around 30 minutes at a draw of about 600 watts. Not bad eh?

I heard that each battery is only about 2 x 4 inches and only around a quarter inch thick. That means they should be very light.

Although, you have to be careful with Lithium Ion packs. They can explode if overcharged.

I think there are some Japanese companies making these. Yoku I believe is one of them.

 

The whole idea to use electrical peltier devices to provide cooling may be limiting your options when it comes to easy human portability.

small mechanical cooling units are possible as well(refrigeration compressors) and fuel(chemicals) can carry a HUGE amount of energy in very small amounts.

Sorry, for the interruption with such negativity, but I think in creating new products one should examine ALL the possibilities, as deeply and widely as one is capable of doing.

 

The whole idea to use electrical peltier devices to provide cooling may be limiting your options when it comes to easy human portability.

small mechanical cooling units are possible as well(refrigeration compressors) and fuel(chemicals) can carry a HUGE amount of energy in very small amounts.

Sorry, for the interruption with such negativity, but I think in creating new products one should examine ALL the possibilities, as deeply and widely as one is capable of doing.

They make refrigerators that can fit in a desk drawer. My full sized energy star fridge draws less power than a light bulb. Small Refrigeration unit, minus refrigerator box, would fit in a backpack, and wouldn't require a power substation to make it work.

 

Hmmm, there are so many factors to weigh. I cant' deny that i envy you all for your ability to comprehend all this, equations were never my strong point and I really regret that I never was able to fully grasp them, especially since I like building and tinkering with electronics. Nevertheless perhaps it is best that I find another means of cooling, what would be the best way to cool down a suit like this again? Mind you, this is a fursuit so it can't be too intrusive as to make someone look like a hunchback.

 

OK...what is a "fursuit"? Got a photo?

Ken

 

OK...what is a "fursuit"? Got a photo?

Ken

Ehhh, it's a bit awkward to explain. I guess I should start with the basics. Fursuits are worn by fursuiters AKA furries. Furries are people like myself who enjoy the concept of anthropomorphic animals. Basically animals with human like characteristics. The fandom is full of fun loving people who like to help other people and have a good time. A lot of people gives us a hard time because they find our pastime weird... And it is. But it's a ton of fun and feels great to be around free spirited and open minded people who don't give a **** about what popular culture says about them.

So that explains the people behind the suits. Now the actual suit part. Fursuits are worn by some furries to portray their fursonas (the animal they associate themselves with, usually has it's own personality traits, markings, etc). But like I said, it's not something that most people enjoy or understand so if you don't care for it, that is fine. For info check these links:

Wikipedia link

Youtube link

And a picture: http://dreamcainineproject.webs.com/photos/Fursuits--we-did-not-make-these/fursuit 22.jpg


Now that i have revealed the weird hobby that me and a bunch of other people do. Let's get back to the subject at hand of a portable cooling system.

 

Are you serious? I have heard about a few weird hobbies but this one takes the top prize.
If you go around pretending to be a furry animal then why don't you cool yourself like a furry animal does? Pant with your tongue hanging out, run into a cold river or stand in a cool breeze. It is fun to run around when it is raining or snowing.
No coolers and no huge and heavy batteries for them.

 

Are you serious? I have heard about a few weird hobbies but this one takes the top prize.
If you go around pretending to be a furry animal then why don't you cool yourself like a furry animal does? Pant with your tongue hanging out, run into a cold river or stand in a cool breeze. It is fun to run around when it is raining or snowing.
No coolers and no huge and heavy batteries for them.

Ok enough with the trolling. It's about as weird as businessmen who decide to paint themselves blue, go shirtless to a football game, and scream. Honestly it's rather fun what we do and it's very enjoyable. I can understand if you don't agree with what we like or do, but you don't need to be rude about it.

*On a second note I find this slightly humorous since you have Scrooge McDuck as your avatar which is classified as a type of Anthro. I love irony.*

 

Really this is not just mockery and sarcasm for the sake of it. The point is that it looks as if you risk putting a lot of effort into a system that is unlikely to be feasible because of its low efficiency.

This could lead to your spending a significant amount of money if you actually try to build a full-scale Peltier-based cooler to take the heat load from a human being.

Probably something based on a conventional closed-cycle fluid refrigerator or heat pump system would be more appropriate.

 

That's amusing. Until this point I was imagining this to be for firefighting or for working on blast furnaces. Any way, if I were going to don such a suit and prance around all day in the sun, I would first put on wet underclothes, and install a fan in the suit; maybe with duct sewn into it, to carry the air throughout.

Look at people work outdoors in hot climates; maybe the migrant workers who mow your lawn in the dead of summer, or people who cross the desert on camels. The wear long sleeves, maybe several layers. This serves to keep the body's own fluid close to the body, and allow for more efficient transfer of heat away from the body. Wear a tshirt into the pool in summer, then go stand in front of a fan. You get cold, even if it's hot outside. The cold will last much longer than if you were shirtless. Maybe install a water pouch that will drip feed down the spine to keep the suit occupant moist. Fans are much more energy efficient that a peltier or a compressors, and it's basically yhe same principle; move heat away from the body, via a fluid.

 

That's amusing. Until this point I was imagining this to be for firefighting or for working on blast furnaces. Any way, if I were going to don such a suit and prance around all day in the sun, I would first put on wet underclothes, and install a fan in the suit; maybe with duct sewn into it, to carry the air throughout.

Look at people work outdoors in hot climates; maybe the migrant workers who mow your lawn in the dead of summer, or people who cross the desert on camels. The wear long sleeves, maybe several layers. This serves to keep the body's own fluid close to the body, and allow for more efficient transfer of heat away from the body. Wear a tshirt into the pool in summer, then go stand in front of a fan. You get cold, even if it's hot outside. The cold will last much longer than if you were shirtless. Maybe install a water pouch that will drip feed down the spine to keep the suit occupant moist. Fans are much more energy efficient that a peltier or a compressors, and it's basically yhe same principle; move heat away from the body, via a fluid.

I'm not certain if a nice fluffy fur suit would feel good if it got all wet. I can see possible mold and smell arising from it if that were the case. The concept is good though since fluid is a great was to dissipate heat.

 

I'm not certain if a nice fluffy fur suit would feel good if it got all wet. I can see possible mold and smell arising from it if that were the case. The concept is good though since fluid is a great was to dissipate heat.

Well then maybe the answer is an intermediary plastic suit between wet undergarments and the absorbent fluffy suit. Like a scuba drysuit, used in reverse, with a fan inside, ducts, and an inlet and exhaust ports.

 

Was I rude to say that you are weird to pretend that you are a furry animal? I said that your activity is weird. I did not say it is bizarre like in the dictionary. It isn't kinky like s**y activities. It is simply weird. If you like doing it then it doesn't bother me. Have fun.

How do astronauts control temperature in their suits? The sunny side is cooked and the dark side is freezing.

 

There appears to be a demand for body cooling in the multiple sclerosis community and it would seem that others have been working on active cooling apparel also. There is a summary of available products here:

http://www.activemsers.org/tipstricks/choosingacoolingvest.html

Ain't the interwebs marvelous!

 

To echo strantor's idea of fans, it would seem that evaporative cooling would be the most simple and uses the individual's own perspiration as the liquid medium. This could be built into the fursuit design. A spaced, porous, shell between the body and the costume. Force air from the outside through the space and then exhaust to the outside. The air could evaporate the perspiration on the skin, and carry it out. This really depends individual's ability to perspire, and on the dew point of the environment. What might work in Phoenix might not work at all in Seattle.

Ken

 

Ok enough with the trolling.

I missed this. No worries, he's not a troll, he's an old codger. There's a difference. Trolls are non value added members who contribute only insults and stir up fights. Old codgers contribute invaluable expert advice acquired over a span of several decades of circuit design and troubleshooting, 90% of the time. The only thing they take in return is the opportunity to use the other 10% of their time to deliver dope slaps to young whipper snappers. The only tragedy here is that you didn't receive the benefit of any pearls of wisdom before your judicial smack down. Stick around, and you will. This forum is surprisingly troll free, and your visit here has been an inaccurate representation of what it's usually like.

This really depends individual's ability to perspire, and on the dew point of the environment. What might work in Phoenix might not work at all in Seattle.

Ken

here where I live, I can't really see just fans keeping one comfy, which is why I went straight to the wet clothes idea. I guess that might be overkill depending on where op lives.