Author Topic: Power pot  (Read 7663 times)

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Offline notzippy

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Power pot
« on: September 07, 2013, 01:36:49 am »
Showed up in G+ today.. http://www.thepowerpot.com/


At $150 quite the ticket price,claims to generate 5W of power enough to charge your phone in a couple of hours

then I found this http://tegpower.com/pro4.htm


For $17 dollars , looks like the same spec to me that's some profit margin...

nz
 

Offline mmagin

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Re: Power pot
« Reply #1 on: September 07, 2013, 02:36:27 am »
The leads on the Power Pot seem to be attacked to the disc on the bottom.  Given that it goes in a flame, this suggests to me that it is a much higher temperature rated device than the usual square devices (that thing you link to looks like the usual Peltier cooler used in reverse.)  Perhaps it's something more like a larger version of the thermopiles found in some gas appliances that generate a few hundred millivolts when they're sitting in the pilot flame.

I'd be very impressed if anyone can build their own Power Pot for less which works nearly as good and doesn't fall apart after a couple uses :)

Would be fun to try, I suppose.
 

Offline Legit-Design

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Re: Power pot
« Reply #2 on: September 07, 2013, 04:24:36 am »


Kipkay already did it, too bad he it made look so fake. He has most of the parts, too bad that poor implementation probably doesn't work. Or it maybe works those few times and will get hot and melt the solder inside peltier.

I suggest you start by doing the homework first, looking at other projects which are similar.
http://hackaday.com/?s=peltier

http://hackaday.com/2010/01/05/generate-electricity-with-a-candle/

http://hackaday.com/2013/04/12/generating-electricity-from-alcohol/

http://hackaday.com/2009/10/05/thermoelectric-solar-power/

One that is reliable and lasts years (in use?) if not decades would be nice to have in case of emergency.
« Last Edit: September 07, 2013, 04:28:09 am by Legit-Design »
 

Offline smashedProton

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Re: Power pot
« Reply #3 on: September 07, 2013, 04:27:52 am »
That's a lot of fuel for a backpacker...   It would take a long time to charge the phone and the gas would be idling..   Flex solar panels are better
http://www.garrettbaldwin.com/

Invention, my dear friends, is 93% perspiration, 6% electricity, 4% evaporation, and 2% butterscotch ripple.
 

Offline Legit-Design

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Re: Power pot
« Reply #4 on: September 07, 2013, 04:34:44 am »
Solar panels don't work in dark, thermoelectric generator would work whenever there is fire. I would probably take a usb boost pack instead, or spare battery, or leave the phone alone turned off and enjoy camping. For real emergency have one the better AA boost packs? I don't know if small AA usb boost packs are worth it, but one with single 18650 li-ion cell would definitely work and only double the size.
 

Offline Rasz

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Re: Power pot
« Reply #5 on: September 07, 2013, 07:28:59 pm »
Kipkay is a retarded scam artist, all of his vedeos are fake, its like watching 'Learning Channel'
Who logs in to gdm? Not I, said the duck.
My fireplace is on fire, but in all the wrong places.
 

Offline Psi

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Re: Power pot
« Reply #6 on: September 07, 2013, 07:42:50 pm »
Using solar panels to charge a usb boost pack during the day is a better plan.

As much as i love anything that uses a peltier, that thing is a pretty ineffective use of weight and materials (gas). And weight is the critical factor when going camping/hiking.
Even if you make dinner in the pot at the same time, that's only going to be 15min or so, not the 2hours needed to charge one persons phone.

That said, if they're goal is to sell it and make money they will probably succeed because it has the cool factor and that's all most people care about.

« Last Edit: September 07, 2013, 07:50:04 pm by Psi »
Greek letter 'Psi' (not Pounds per Square Inch)
 

Offline JackOfVA

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Re: Power pot
« Reply #7 on: September 08, 2013, 06:05:53 am »
There are modestly priced combination hand cranked flashlights and phone chargers. Phone is charged over a 5V USB port, and from what I've read some model phones implement charging in a non-standard way, incompatible with some of the hand cranked devices. 

Amazon.com, for example, has several versions available and the associated reviews thrash out whether they work with certain phones or not.
 

Offline Marco

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Re: Power pot
« Reply #8 on: September 08, 2013, 06:18:34 am »
Why can't I get a cheap free piston stirling engine generator?
 

Offline ElectroIrradiator

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Re: Power pot
« Reply #9 on: September 08, 2013, 06:34:06 am »
Why can't I get a cheap free piston stirling engine generator?

Because they are hugely inefficient while small, due to excessive heat loss to the surroundings. Once you build them properly to reduce the heat loss, then they are no longer simple nor inexpensive.
 

Offline Marco

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Re: Power pot
« Reply #10 on: September 12, 2013, 06:50:55 am »
Ehh ... you can be pretty inefficient before you start getting close to Peltiers.

A lot more inefficient than this.
 

Offline Tost

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Re: Power pot
« Reply #11 on: September 19, 2013, 08:30:51 am »
Because the temperature-difference is quite high in that setup efficiency with a commercial thermal generator can exceed 5 %. When heating up 1.5 kg of water for tee at least 140 Wh are required. So you get 7 Wh electrical energy, respectively 1400 mAh @ 5 V. So the concept can work technically.

But for sure not economically, batteries are quite cheap compared the hardware which would be required.

The thepowerpot is a joke. For heating up 1.5 kg of water in a acceptable time span (5 min) I need at least 1,7 kW. When charging a phone with 500mA @ 5V is that an efficiency of 0.15 %...
 

Offline mtdoc

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Re: Power pot
« Reply #12 on: September 19, 2013, 08:49:45 am »
I have one of these biolite camp stoves.  It is made very well and works very well.

With a shoe-box sized bundle of small sticks and twigs you can cook a meal and charge an iphone.

The price has gone up since I bought mine but it's still worth the money IF you have the need ....
 

Offline Tost

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Re: Power pot
« Reply #13 on: September 19, 2013, 10:02:56 pm »
Well mtdoc if you have fun with using it it’s all right. But it’s the same thing: efficiency is around 0.1% so you will need roughly 50g of alkaline D-cells to charge your phone, but 1500g (!!) of wood (or 500g of butane) with these devices...

Or another calculation: If you go out into the wilderness for e.g. 1 week and you use the cooker approx. 1h/day you will get 17,5 Wh (=0.5A * 5V * 1h * 7). That’s approximately the energy you can source from a single D-cell. Comparing weight or price is simply pointless…

Another interesting point: On the page you linked is written „Charging times vary […] by strength of fire “. That’s technically questionable without integrated energy-storage, because USB-charging power is primary controlled by the power receiving device. This problem applies to solar chargers without internal battery in the same way.
« Last Edit: September 19, 2013, 10:05:23 pm by Tost »
 

Offline mtdoc

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Re: Power pot
« Reply #14 on: September 20, 2013, 02:07:14 am »
Well you'll get no argument from me that the thermoelectric is  very inefficient.

But the usefullness of this stove (the Biolite - not the one in the OP) is not theoretical for me - I've actually used it and will continue to.

The USB charging is slow and weak - I have not measured the output but it typically takes several hours of boiling water/cooking with full bore flame to bring my iphone up from say 10%  to 90% SOC or charge a pair of depleted aaa batteries (with usb charger).

But when camping it is not unusual - especially if boiling water to purify, cook and make hot beverages - to have the stove going for several hours.   With a gas stove you would be worried about fuel consumption but with this stove the  equation totally changes since  a few minutes gathering twigs can provide an hours worth of fuel. (BTW - where I live in the Pacific NW of the US - gathering 1500g of twigs only takes about 15  minutes!)

Even without the USB charging I would use this stove because it's a very efficient rocket stove with the thermo-electric running a small fan that allows a very efficient, hot fire with minimal wood fuel. The usb charging - poor as it is - is just an added bonus.

Again - no argument that there are much better ways to charge an iphone, etc but in a situation where you're cooking anyways and the alternative would be carrying lots of batteries or using equally inefficient small thin film solar chargers - this bit of charging the stove provides serves a useful niche.
« Last Edit: September 20, 2013, 02:20:11 am by mtdoc »
 

Offline Tost

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Re: Power pot
« Reply #15 on: September 20, 2013, 03:24:01 am »
I’m totally with you, it’s a nice idea. But “carrying lots of batteries” instead is not true, even if you would run the stoves for hours, the battery-equivalent (Alkaline or LiPo) will be lightweight compared to the stove in most realistic scenarios.

And working 15 min for a equivalent value of 0.40 US$ alkaline-cells isn't a enormous wage ;)
 

Offline mtdoc

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Re: Power pot
« Reply #16 on: September 20, 2013, 03:55:38 am »
I’m totally with you, it’s a nice idea. But “carrying lots of batteries” instead is not true, even if you would run the stoves for hours, the battery-equivalent (Alkaline or LiPo) will be lightweight compared to the stove in most realistic scenarios.

And working 15 min for a equivalent value of 0.40 US$ alkaline-cells isn't a enormous wage ;)

Right - but ya gotta carry a stove anyways and you have to carry fuel with a typical stove. Fuel does add significant weight to extended back country trips and so would batteries if you were to use them intensively (reading books  on the iphone and using it as a GPS does that!).

Since I've got a bum knee, I'm a weight weenie  ::) when I'm backpacking - even a few grams less on my back is important.

For short trips or trips where little wood is available (high alpine, desert, etc) then a gas stove and batteries (and or solar charger) makes more sense for sure.  But again - the Biolite does fill an important niche..... It's also just kind of cool to use- and good to have along if your run out of gas. I've brought it along on car camping trips just for that reason ..
 

Offline Tost

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Re: Power pot
« Reply #17 on: September 20, 2013, 05:56:03 am »
Sorry for insisting so obtrusive on my point, but please have a look at the numbers.

“even a few grams less on my back is important”

If you use a empty tin can as stove and replace the same energy you would be able to suck from your usb-stove during the whole trip with battery-energy you will be still have to carry less weight. Make the calculation.

Btw. for car camping that measly 2.5W is beneath notice. Check out your car battery capacity.

But thermoelectric generators are not bad at all, check out this one: http://en.wikipedia.org/wiki/File:Soviet_RTG.jpg ;)
 

Offline mtdoc

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Re: Power pot
« Reply #18 on: September 20, 2013, 06:26:04 am »


If you use a empty tin can as stove and replace the same energy you would be able to suck from your usb-stove during the whole trip with battery-energy you will be still have to carry less weight. Make the calculation.


Oh - believe me, I've done the calculations.

Empty tin can for a stove?:-DD

Have you ever tried to boil a quart of water with such stoves?  Melt multiple pots full of snow? I have. When properly fueled, the biolite can do these tasks as fast as my MSR XGK. 

The point is this.: The Biolite is a very efficient stove that puts out many BTUs - with twigs. It weighs more than a traditional light weight liquid or cannister fuel backcountry stove but when you account for the weight of fuel - the calculations come out that for extended back country trips (more than a few days) the extra weight of the stove is more than offset by not needing to carry fuel

The thermo-electric battery charging is just a bonus. Not the prime reason to use the stove but it does mean no need to carry extra batteries -which are not free or weightless.

Car camping?  well of course the battery charging is just a fun novelty in that situation - as I said -no logical reason to use it then - but the stove  is nice to have if you run out of canisters or liquid fuel for your stove and not having  to trek to the closest store (sometimes miles from a campground) to buy fuel to cook a meal.



 

Offline Tost

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Re: Power pot
« Reply #19 on: September 20, 2013, 07:16:57 am »
Ok, OK stupid idea with the tin can ;)

surtenly I simply don't like these products that pretend to be more than they are. even if they may make sense in some cases. (and outdoor products are generally suspicious to me ;) ) Here in Europe we have no "extended back country", so I can't judge ;)
 

Offline mtdoc

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Re: Power pot
« Reply #20 on: September 20, 2013, 07:27:26 am »
Hey no worries.  I'm a total noob with electronics  - just not when it comes to back-country camping. Rare that I see something here on EEV blog where I have some significant knowledge ... :o

Good to be skeptical about these things. To be honest I was very skeptical about the Biolite which is why I was pleasantly surprised.  It is a very niche product but unlike the "Power Pot" in the OP I think it does make sense in some situations. 

 


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