FlameStower - USB charger powered by fire

[malandrew]

I think they got the idea right, but designed it around the wrong source first. Using fuel to power my devices means I need to carry more fuel with me. Why do that when I can just carry cell phone backup batteries like this one: http://mylimeade.com/

Instead this should have been designed around something I can throw in a campfire with some sort of protective spiral metal cabling to snake out of the fire to a box with a USB connector. The metal cabling could be similar to those used on high temperature oven thermometers.

[shabble]

The cable isn't likely to be the limiting feature here. The method of energy conversion doesn't just require heat, it requires a temperature gradient across the device. Here they're putting the tip in the fire to heat it, and the little bowl at the back full of water is used to cool the other end, thus getting a good temperature difference.

In contrast, throwing hte whole thing into the fire might work briefly while the heating was uneven, and the water hadn't all boiled off, but as soon as it reaches the same temp all over, no more power. And if it's all in the fire, even the water evaporative cooling isn't going to help much, vs when it's out of the direct flame/hot air stream at the edge.

I imagine you could design a in-fire version using a heatpipe to transfer energy out to a radiator/cooler somewhere, but that would be much more fragile and/or expensive.

What we really need is MEMS (or at least, really teeny, zero-maintenance) Stirling engines :)

[jacquesm]

> Instead this should have been designed around something I can throw in a campfire with some sort of protective spiral metal cabling to snake out of the fire to a box with a USB connector.

That won't work, see:

http://en.wikipedia.org/wiki/Thermal_efficiency

Your problem is that the sink capacity of your device is closely related to its mass so unless you let something change phase (for instance, water evaporation) you're going to run out of capacity to store the heat before you have your phone charged. This will result in a lack-of-temperature-gradient which means you will no longer produce power. Compare with a Peltier element that is kept equally hot on both sides or equally cold.

[pstuart]

You need a temperature delta to generate the electricity. Where is the cool sink in your proposal?

[nnash]

Wait I'm confused, where does fuel come into this? All you need to start a campfire is a bit of flint and kindling.

[nollidge]

You don't need to bring fuel, assuming there's wood around you to burn.

[ZoFreX]

For a given weight/volume surely a gas canister works out as more energy than a backup battery?

[nlh]

First thought: "Awesome - power for phone if everything goes to hell."

Second thought: "Wait, if everything goes to hell, there's not going to be any cell service."

Third thought: "Oh well, at least I'll have Candy Crush."

[tesseractive]

Perfect for using your offline cached copy of Wikipedia to recreate civilization after the apocalypse?

[baddox]

Get into amateur radio and you'll be one of the most useful people around with everything goes to hell.

[mpapi]

I brought a BioLite stove with me on a recent camping trip and loved it. That had other advantages: easy to get a fire going during a very rainy week, no fuel to carry (in the White Mountain National Forest, anyway) and it was pretty easy to cook with.

USB charging didn't seem all that useful at first, but with a USB-rechargeable LED lantern it ended up being great. If that's all you really needed, you could get it from the FlameStower without the battery + fan machinery of the BioLite, I guess.

[hellopat]

I've been having an internal struggle regarding the purchase of a BioLite stove. The primary reason I haven't is because of it's weight. As a backpacker, the stove is just way too heavy to carry on a trip (weekend trips, fine - but anything longer it would have to stay behind).

The FlameStower seems much more practical for longer trips because of it's weight / bulk.

[kalleboo]

Last year there was the PowerPot, which is the same principle on the bottom of a cooking pot http://www.kickstarter.com/projects/david-toledo/the-powerpo...

[positivejam]

My buddy is the VP of Web/Marketing there (Power Practical). Their Kickstarter last year went really well. Here's a link to their current product page: http://www.thepowerpot.com/

[queeerkopf]

another similiar project: http://www.biolitestove.com/

[zokier]

I must say the powerpot looks far more sensible design.

[nobodysfool]

There's also the tPOD1 which would be less expensive, it operates off tea candles...

http://www.buytpod.com/

http://www.kickstarter.com/projects/tpod1/tpod1-thermoelectr...

$50

The tPOD5 can charge a smartphone, it's a bit more expensive, and doesn't run on tea candles, you put it over a camp stove.

Point is, these things exist, this kickstarter doesn't seem to improve on any of them except perhaps make the designs cheaper, but they cost more. I'm sure they can make a nice profit on these devices if they sell, and if they can handle their manufacturing costs. If not, it would be cheaper to buy one of the alternatives and ship it to people instead of running your factory.

[mfonda]

Stoves with built-in USB chargers already exist as a commerical product. For example, check out http://www.rei.com/product/846334/biolite-wood-burning-camps...

[jpalomaki]

A DIY version by Timo Noko [1]. The same guy has been tinkering also with some other interesting stuff [2].

[1] http://www.youtube.com/watch?v=R1A5qc872Ks [2] http://koti.welho.com/tnoko/

[sgwil]

And here I was hoping I could finally buy a USB powered flamethrower.

[jrochkind1]

Oh man, I do and don't want to see the efficiency and carbon-output per joule generated of this device compared to actual grid energy. Not to mention particulate air pollution.

Although it will depend on what you are using for the source of your 'fire', it's not gonna look good.

This is a weird idea.

[NathanKP]

It's not intended to be an efficient clean power source. It's intended for people who want to do something like hike the Appalachian Trail and want to be able to charge their devices using the same fire they use for cooking / heat.

[0xdeadbeefbabe]

I'm going to get one so I can carry coal instead of batteries.

[hfsktr]

Great for the post-apocalyptic world!

Maybe good for short term natural disasters or outdoorsy types who want to stay connected.

I find some humor in that having a cell phone on and charged is still 'off the grid' (I know they meant electrical grid).

[sbierwagen]

I wrote about something very similar last year, the BioLite camp stove: https://bbot.org/blog/archives/2012/06/13/biolite_camp_stove... (I'd argue that the BioLite is a better product, despite being twice as expensive, since it can run on wood.)

A problem with both products that they use the thermoelectric effect, which is miserably inefficient: The BioLite generated 2 watts from a thermal power of 5500W, for a thermodynamic efficiency of 0.036%

Solar panels, on the other hand, don't need to burn anything at all.

[brandon272]

I see this product as having two target markets:

1) Outdoorsy people who carry fuel and find themselvea away from electricity.

2) People who are going to burn their homes down trying to recharge their iPhones during power outages.

[jebblue]

It looks like something one could craft in Minecraft so I like it, seriously though, I've been shopping for a solar charger just in case there is some unforseeable disaster and I need to be able to keep the GPS and compass working at least. This looks like a good alternative, I looked at two of the competing products in the comments here but this one seems to me to keep the most distance between the heat source and the electrical cord while still staying out of the way of my cooking. The collapsible design seems like a good idea too.

[Pxtl]

2-3W? That means it's only a 0.5A, right? A lot of devices don't even charge properly off of a 0.5A USB source.

[pudquick]

While they may not fast charge, many of the devices will trickle charge - simply because the original USB 2.0 spec didn't require high amperage. In fact, 2.0 spec allowed for a max of 5 'unit loads' with a unit load of 100 mA (5x 100 mA = 0.5A). Putting out more than that was against spec unless the port was specifically marked as a 'charging port' per the Battery Charging specification (you may have noticed USB ports with battery icons next to them).

It wasn't until USB 3.0 that the limits were increased. Additionally the Battery Charging spec was re-written to increase limits for charging ports.

If you can plug your device into any single USB jack on a computer (not just ones with a battery icon next to them) and it will charge, it will likely charge with this project.

[fudgy73]

This, to me, isn't very novel. Why can't you just wait for the sun to come up and carry a 140g solar panel? I suppose this may be useful in a very rare emergency situation, but otherwise, nahhh.

$ don't lie, though, and it looks like they have almost reached their goal.

[rom16384]

It's not new at all, see this 1956 kerosene radio: http://blog.modernmechanix.com/kerosene-radio/

[jpalomaki]

Some people are traveling in places where you don't get that much sun shine. Or you might what to charge your devices in some shelter where you just have a fireplace.

[mmanfrin]

Congrats to Adam (and Andy) -- went to elementary/middle/high school with him, been neat to watch this product evolve over the past year on facebook.

[goshx]

Does anyone bother to create something similar that would help 3rd world electricity problems? oh, I forgot... they don't have smartphones.

[c-oreills]

Biolite does this. Traditional stoves produce a huge amount of smoke which is bad for people breathing it. BioLite reduces the smoke, but they found that men were usually in charge of purchasing decisions and weren't around when cooking was being done, so had no incentive to invest in the smokeless stoves. Adding electricity to the stove meant that men were more likely to buy, thus helping their family's health.

http://www.bbc.co.uk/news/business-24116000

[timthorn]

Mobile phones are quite widespread though.

[lafar6502]

a superior technology is known for several years, but still can't make ends meet

http://www.forbes.com/sites/michaelkanellos/2013/01/31/why-a...

[fnordfnordfnord]

Mongolians will love this.