DSC_3385

By Evan Ackerman

This thing is, seriously, the highlight of CES for me (so far) this year. 3D TVs and eBook readers are fine, but there’s nothing amazing about them.

The Airnergy Charger is amazing, it’s something one might see in sci-fi movies or tv shows. This little box has, inside it, some kind of circuitry that harvests WiFi energy out of the air and converts it into electricity. This has been done before, but the Airnergy is able to harvest electricity with a high enough efficiency to make it practically useful: on the CES floor, they were able to charge a BlackBerry from 30% to full in about 90 minutes, using nothing but ambient WiFi signals as a power source.

The Airnergy has a battery inside it, so you can just carry it around and as long as you’re near some WiFi, it charges itself. Unlike a solar charger, it works at night and you can keep it in your pocket. Of course, proximity to the WiFi source and the number of WiFi sources is important, but at the rate it charges, if you have a home wireless network you could probably just leave anywhere in your house overnight and it would be pretty close to full in the morning.

DSC_3384

Here is the really, really unbelievable part: RCA says that the USB charger will be available this summer for $40, and a battery with the WiFi harvesting technology will be available soon after. I mean, all kinds of people are pushing wireless charging, but this would hands down take the cake… It doesn’t need a pad and it’s charging all the time, for free, in just about any urban environment.

We didn’t think you’d believe all this, so we made RCA explain it all on video:

Yeah, we’ll definitely be keeping you updated on this one.

Update: According to George from top5hosting.co.uk those wifi battery chargers did not have success for a few reasons:

– When you draw power off of it, you reduce greatly the WiFi signal and it acts as if the router is under constant DoS(Denial of service) attack

– It is not a ‘green’ technology. It is less efficient than a plug-in charger and it comes from the same source. What this device amounts to is theft from whoever pays the electric bill where the router is located. If it’s in your own home then it’s just a waste of energy.

Wireless charging is on the horizon, but not through your WiFi.

RELATED ARTICLESMORE FROM AUTHOR

174 COMMENTS

  4. Great, now the homeless people could not only steal your home wifi but also steal the power from your home wifi to charge their smart phone/electronics. At least in a twisted world that'll be the case

  6. This is awesome. He mentions in the video that it depends on your proximity to the wifi signal, but what he doesn't mention is whether it's affected by the number of wifi signals nearby. I imagine there's a hell of a lot more traffic at CES than there is in my living room. So would it take longer than 90 minutes to charge that blackberry at my house?

  7. Color me skeptical.

    If I read the internet right, the maximum allowed power of a wifi antenna is 1 watt, and a random Blackberry battery is 3.7v and 1100 mah, or about 4 watt-hours of battery. So with 100% capture (meaning totally blocking the wireless router), perfect conversion, and perfect charging we'd be looking at 4 hours to charge. But practically, capture rates will be much lower, so I'd bet this thing can't continuously power even a Blackberry off of wireless signals.

    My guess is that the wifi charging bit is mainly a gimmick, and this thing is mainly an external battery. I expect that anybody using one of these regularl will have to charge the Airnergy by plugging it in.

  8. I can't see this working out either. I can't imagine it being possible to recharge a phone, iPod, etc. from the power sucked out of a light bulb in any reasonable time, which is what this is more or less equivalent to.

  10. I think people are not understanding how this works. It has a battery in it. It charges it's own battery off of wifi signals. This takes some amount of time that is not clearly defined. Then when you plug a blackberry in it dumps whatever amount of battery it has into the blackberry. So the actual “charging” of the blackberry won't take long. However, how long it will take the device to recharge itself is not clear.

    This device doesn't really offer many real advantages(besides coolness factor) over a device I built recently that is essentially a usb plug attached to some rechargeable batteries. Except of course that this device is far more expensive. I have a hard time imagining realistic scenarios where this would be more useful though.

  11. I don't think you are understanding this product either. He said the long term goal is to put this in an OEM battery. Now if you live in somewhere say like NYC, your cell phone would be recharging itself 24/7. Just think of the number of WIFI signals you encounter anywhere on that island. Also what cell phone manufacturer wouldn't want this tech in their batteries is a better question to me. Automakers are building in WIFI into cars etc. This signal is so abundant especially in high population density areas. So to me, this tech has huge potential, not just coolness factor.

  12. Are you serious? Something like a 60W bulb is enough to charge almost 22 copies of my cell phone at once, full blast! (the charger max output is 5v, .55A so 2.75W to power the adapter).

  14. I'm dubious.

    It probably takes 3-4 days to charge this external unit purely on wifi signal, just so you can partially recharge your phone. The OEM battery will probably add some nominal amount of battery life, but far from enough to throw away your AC charger…unless you can plug it into a cold fusion reactor.

  15. Here's some math. Long story short, by my calculations, 100% efficiency and absorption at 5 feet away from a 100mW home router, (reasonable figures), it would take 34.5 years to charge that blackberry battery.

    It's not a Dyson Sphere, so you only get the power that hits the antenna.
    Surface of a sphere = 4pir^2, r = 60″ (5 feet).
    Surface area of a 5' sphere = 45,216 square inches.

    The device appears about 2″ x 3″ = 6 square inches.
    The device then picks up, best case, 0.000133 of the power out from the router, which is 100mW, so.. 0.0133mW

    If you leave it there for 24 hours, 0.0318 mWh are stored.
    According to Will's battery, it has ~4,000 mWh capacity.

    So, it would take 12,579 days, or 34.5 years, to charge your blackberry battery once, presuming 100% absorption, no losses.

    I call BS. Even adding up all the laptops, cell phones, routers, portable phones, everything, all the noise in the RF spectrum that could hit that device, I don't see it charging the internal battery even in a week.

    Of course, once the internal battery is charge, hey, no problem, you can dump that power into whatever you want to charge, easy.

    I don't know much about RF though. Did I miss anything? How's my math?

  16. I like this thing too, im a little skeptical as per Cynake demonstrating the maths, but when i check how much signal my laptop at home is intercepting i get 16 wifi overlaping (17 including my own) with 2-3 green bars.
    The area of the devise is a major problem, because basically you are trying to intercept a diffuse energy source (kind of like solar panels or windmills), maybe they could make an accesory which in effect is a 4 square meter wall hanging of embedded conductive wire and increase the 'reception' some 10,000x, just hang the thing up behind a bookshelf.
    That would recharge the Airnergy on-board battery every 29 hours for topping up the cellphone and ipod.

  21. I don't think any of you understand. This device would take about 100 days to charge a device by harvesting wifi signals. I can't believe RCA are trying to pull such a fast one.

    P.S. I have some snake oil for sale. $39 a pop. It can cure cancer

  22. I don't think either of you understand. RCA are pulling a fast one. I think they sacked all their engineers and replaced them with marketing executives.

    It would take about 100 days to obtain a single charge from multiple wifi sources. I can't believe RCA are trying this on.

    P.S. I have some snake oil for sale. $39. It can cure cancer.

  23. I don't think either of you understand. I think RCA may have replaced all their engineers with marketing executives.

    It would take over 100 days to obtain a single charge if you lived in Manhatten. I can't believe RCA are trying to pull this crap. In fact I can't believe ohgizmo is giving it credibility.

    P.S. I have some snake oil for sale. $39. It can cure cancer

  25. In the average urban location you would likely be able to harvest 1mW of power (Nokia have a prototype device that harvests 3 – 5mW in optimal conditions).

    That means that a single charge would take approximately 100 days.

    It would save you about $0.01 cent / year.

    In order to recoup the manufacturing energy / transportation / material extraction, it would take over 100 years of constant use. That doesn't include recouping the energy wasted by employing the RCA marketing department.

  28. I did the same calculation, and concluded that it would be lucky if the device could counter the self-discharge of a Li-Ion battery.

    I modelled a 10cm x 10cm antenna, and concluded that if you could drop it within a couple of meters of ten 100mw sources, you MIGHT get almost 1 milliwatt. If it worked with 100 percent efficiency.

    This is either an early April Fool's joke, or somebody is a lying liar.

  36. Wow, they should really build this into phones to extend the battery life while on the go, especially considering the saturation of WiFi in most cities.

  38. hahahah how this things virals itself over the internet right now, and every foolish “techblogger” is just copying it without even having read the comments here. Just my 10 year ago school math and some common sense is pretty enough to tell, that this is a hoax (a good one though). This one really lets all the dumb techy copybloggers look like fools. (and even the german connect magazine took the story)

  39. Even if it could work, I do not want such devices to cause an increase of power in WIFI signals emissions everywhere !
    And since WIFI was not designed to carry charge power, this would probably would cause inefficient full WIFI power emission (not even directed towards the device…. 360° full power emission to just try to charge -inefficiently- such a gadget ?)

  42. You people who think this won't work and have even proved it with maths, let me ask – do you think RCA built a prototype at great expense and then took a stand at CES at great expense and risk to their reputation WITHOUT TESTING THE DEVICE FIRST? Are they sat around in their office now saying “Oh damn, you know what, we should really have tested this before we unleashed it at a major exhibition, silly us” or “people will never notice it takes 100 years to charge”. FFS get real.

  43. Yes – I do. Just as Nokia did in June with their nonsense released through MIT and promptly retracted. How long will it take before RCA realise that it is positively damaging to their image to put “bad science” like this.

  44. Yes – I do. Just as Nokia did in June with their nonsense released through MIT and promptly retracted. How long will it take before RCA realise that it is positively damaging to their image to put “bad science” like this.

  45. Yes – I do. Just as Nokia did in June with their nonsense released through MIT and promptly retracted. How long will it take before RCA realise that it is positively damaging to their image to put “bad science” like this.

  46. Unfortunately you are wrong… I work as an electronic engineer and can guarantee that all this is an optimistic marketing stunt. Unfortunately there are many good examples of vaporware and snake oil out there.

    Harvesting power from ambient RF signals is a well known technique but it is only suitable for VERY low power sensor devices that require remote power.

    If they release the device they will almost certainly release it with the ability to charge up the internal battery manually via USB socket, therefore hiding the miniscule ability to 'harvest' power. I am sure the example at the show already had its internal battery fully charged when it connected to the blackberry.

    Potential benefits:

    1. Save the user money by harvesting free power – not a cats chance. It would take multiple [human] lifetimes to recoup your initial expenditure.

    2. Good for the environment – again a single device would need to harvest energy for 100+ years in order to recoup the energy required to develop, produce and sell it.

    3. Convenience – it will still require manual charging, meaning that the user will have to charge TWO devices rather than one.

    As a standalone device it will NEVER be more than a spare battery that needs to be plugged in to be charged. Integrated into a battery there is marginally more potential but it will NEVER EVER EVER be suitable to keep a smartphone topped up without manual charging.

    As for the math – I have to use it everyday as part of my job to do these types of calculations. Sometimes people calculate wrong… but in this case, the math don't lie…

  47. All discussions on feasibility assigned, you shouldn't even TRY to use the Airnergy device in Germany, as it's illegal (§248c StGB, “Entziehung elektrischer Energie”) – it's just as illegal as putting up an antenna to draw electricity from the transmissions of nearby radio stations.

  49. Apart from the math & physics which clearly show that this device won't work, there are some more points why it doesn't make sense:
    – Saving the environment? The power has to GET from somewhere. It comes out of the walls, out of the sockets of the people who own the WiFi routers. The routers draw the power, and they'll increase their sending power if reception / transmission deteriorates.
    – Conservation of energy: What you give to one device, you have to take from another one.
    – Multiple hotspots? Great, so the power you need is like 100,000 times (or even a million times) too low, and you want to multiply / increase the power by a factor of what? 20 visible hotspots? Big deal, only 5,000 times too low. What we'd need are orders of magnitude, not simple “mutliple hotspots”.
    – Health factors: So many people are scared by electrosmog and all the RF radiation etc. out there. Don't you think that if you could charge a battery “from the air”, that radiation / RF would also hurt your body?
    – WiFi is allowed to be used in hospitals. It's got a very low power output, compared to mobile phones for example.
    – If everyone could simply take so much transmission power from a WiFi hotspot, its signal quality would deteriorate and everyone else (wanting to surf the internet) would be off worse.

  53. Wow this gadget is so AWESOME! I can just imagine my phone charging itself all day while I am out and about, finally a company innovative enough to harvest all that free energy from Wifi!

  54. Well this is either a hit or miss. But either way a great start in the process and road towards achieving things of this nature. I am hoping for success at $40. At least they aren't charging an arm and leg for it.

  55. Yea, they're not charging an arm and a leg, but the way I heard it, they're not even charging a phone. 🙂 Sorry, I couldn't resist.

    I'm anxious to see if it actually hits the market this summer…

  59. Just to put it in context, even in a magical mythical world where it was able to replace your wired mobile charger completely, it would take about 80 years to recoup your initial outlay of $40. A smartphone consumes approximately $0.50 a year of electricity (heavy users can double this value – only 40 years payback).

    This is verging on fraud. I am truly shocked at the audacity of RCA… I will also be very shocked if it makes it to market – the return rate would likely be very high once users realise how little power can be harvested.

  60. I am skeptical of the ninety minute charge of the cell phone (was the Airnergy Charger’s internal battery empty to begin with?), but for harvesting radio waves, I cannot image you could find a better location than a huge trade show.

  61. Read about NIKOLA TESLA and try to be more open minded, if the Wright brothers would have given up on flight someone else would have figured it out. And for the math geniuses try reading about tesla, he worked for Thomas Edison and help perfect electrical current that we use today. The same elctricity you are using to power your computer or whatever electronic device you are using to Bash RCA and the component they have made. Lets see if it works before we pass judgement, like people have done so many times before in the past.

    http://www.teslasociety.com/biography.htm

    The International System of Units unit measuring magnetic field B (also referred to as the magnetic flux density and magnetic induction), the tesla, was named in his honor (at the Conférence Générale des Poids et Mesures, Paris, 1960), as well as the Tesla effect of wireless energy transfer to wirelessly power electronic devices (which Tesla demonstrated on a low scale with incandescent light bulbs as early as 1893 and aspired to use for the intercontinental transmission of industrial power levels in his unfinished Wardenclyffe Tower project).

  63. There is no RCA any more. Thompson (a French company) licenses out the name. It sounds like they licensed it to somebody they should not have.

    It didn’t cost much at all to build that prototype… because it doesn’t work. If anything, it’s probably nothing more than a usb-charged backup battery.

  64. There is no RCA any more. Thompson (a French company) licenses out the name. It sounds like they licensed it to somebody they should not have.

    It didn’t cost much at all to build that prototype… because it doesn’t work. If anything, it’s probably nothing more than a usb-charged backup battery.

  65. There is no RCA any more. Thompson (a French company) licenses out the name. It sounds like they licensed it to somebody they should not have.

    It didn’t cost much at all to build that prototype… because it doesn’t work. If anything, it’s probably nothing more than a usb-charged backup battery.

  66. Yes, it can charge a Blackberry in 90 minutes from its internal battery. The question is, how long does it take to charge its internal battery from WiFi. He never answers that question, and in fact dodges it quite expertly.

    This is snake oil.

  73. lol someone claimed that RCA was risking its name, why would a big company do that?
    RCA is dead. has been for years, its name got sold off, its not the rca you knew. happens all the time these days.

  74. Nikolai Tesla was an innovator. He did things that nobody had done before. The principles that this device rely on are however very well known and already used in certain applications. There are several well known universities working on the use of this sort of technique. Unfortunately what RCA has done is purely a marketing stunt. Unless they have discovered a new and previously unknown law of physics (which would be much bigger news than the device itself) this will never give the benefits some people here seem to believe it will.

  76. I think ultimately Cynake and Rick have it pinned down. There is no practical way this could work. It obviously is better thought out than most “free” energy schemes in that you do end up with a trickle, but not nearly enough to be useful.

  77. Actually, 4 square metres would increase the reception only 1,033x, so it'd charge in 12 days (minimum), assuming the AP was no more than 1 metre away from the middle of the conductive hanging. If your neighbour also had an AP just 20 metres away, their power contribution would speed things up by almost 0.08% (13 minutes quicker).

    You might be able to bring this down to a mere 40 hours if you used 6 of these wall hangings, arranged in a cube around the router so that they absorbed 100% of the AP's output 🙂

  81. I love products like these because they remind me that even if I’m a complete failure in life I can still make money selling good old fashioned snake oil.

    Did you know that due to the high volatility of snake oil that you can harvest energy from living snakes by condensing oil droplets from the air around them? Think about it, just one snake (which on a yearly basis generates over 1000mWh’s of snake oil energy) living in and around your home could generate enough energy to half charge your cell phone. Additionally snake oil doesn’t break down in the atmosphere so there is a large amount of snake oil energy dispersed in the atmosphere even in areas with relatively low snake densities. Clearly this is situation is preferable to that of collecting energy from wifi. Will wifi energy collection work at the North Pole? No, but snake oil will.

  82. I love products like these because they remind me that even if I’m a complete failure in life I can still make money selling good old fashioned snake oil.

    Did you know that due to the high volatility of snake oil that you can harvest energy from living snakes by condensing oil droplets from the air around them? Think about it, just one snake (which on a yearly basis generates over 1000mWh’s of snake oil energy) living in and around your home could generate enough energy to half charge your cell phone. Additionally snake oil doesn’t break down in the atmosphere so there is a large amount of snake oil energy dispersed in the atmosphere even in areas with relatively low snake densities. Clearly this is situation is preferable to that of collecting energy from wifi. Will wifi energy collection work at the North Pole? No, but snake oil will.

  83. I love products like these because they remind me that even if I’m a complete failure in life I can still make money selling good old fashioned snake oil.

    Did you know that due to the high volatility of snake oil that you can harvest energy from living snakes by condensing oil droplets from the air around them? Think about it, just one snake (which on a yearly basis generates over 1000mWh’s of snake oil energy) living in and around your home could generate enough energy to half charge your cell phone. Additionally snake oil doesn’t break down in the atmosphere so there is a large amount of snake oil energy dispersed in the atmosphere even in areas with relatively low snake densities. Clearly this is situation is preferable to that of collecting energy from wifi. Will wifi energy collection work at the North Pole? No, but snake oil will.

  87. You guys putting up your so-called physics math are not using your brains… taking the energy from the signal wouldn't work (of course it would take too long), so this device couldn't do that and work. It most likely has some wi-fi reactive material that vibrates or moves at the 2.4 Ghz (or whatever) signal, which causes physical motion which charges the battery. I guess that reason why you haven't been on the forefront of a technology like this and they have is because of the same close-mindedness and criticism that you display. Stop watching so much Big Bang Theory.

  88. You guys putting up your so-called physics math are not using your brains… taking the energy from the signal wouldn't work (of course it would take too long), so this device couldn't do that and work. It most likely has some wi-fi reactive material that vibrates or moves at the 2.4 Ghz (or whatever) signal, which causes physical motion which charges the battery. I guess that reason why you haven't been on the forefront of a technology like this and they have is because of the same close-mindedness and criticism that you display. Stop watching so much Big Bang Theory.

  89. “It most likely has some wi-fi reactive material that vibrates or moves at the 2.4 Ghz (or whatever) signal, which causes physical motion which charges the battery.”

    Meaning, it produces more power than it uses? Sorry, but your theory makes less sense than the original.

  90. Well, you’re right about there being some mechanism involved that we’re unaware of, but you cannot get more energy out of a system then you put in. So if they really are just using the 2.4Ghz spectrum, the other posters are correct, since you could not, using only the 2.4Ghz signal, cause “vibrations” that produce more energy than was inherent within the signal. Energy cannot be created out of nowhere, so if it’s not already stored in the phone, and it’s not in the signal, then you’ve got some laws of physics to violate in order to have a successful product.

  91. “taking the energy from the signal wouldn't work…It most likely has some wi-fi reactive material that vibrates or moves at the 2.4 Ghz (or whatever) signal”

    The signal couldn't do it, so it must be the signal?

    Uhhh…what?

  93. Dude, even if this worked (which it can't), and even if homeless people had a bunch of electronic devices, and all bought this device for each one (which is highly unlikely), the power that this thing claims to absorb would be power THAT IS LOST TO YOU ALREADY. This device doesn't suck power out of your wifi antenna like a freaking vampire, it (supposedly) work by absorbing the power you are broadcasting anyway. When your wifi is on it outputs energy in any direction, and you don't magically get that power back if a device doesn't make use of it. It's just gone. I mean, duh.

  95. My mind is so open about this that I plan to order ten! Maybe a hundred! This device, along with my perpetual motion machine and pills that turn water into gasoline, will make me the energy king of the neighborhood!

  96. The analysis ignores an important detail: reflection. If you put the device 5 feet from a hotspot, it’s not just going to receive the energy from a 6 square inch cone, but also from waves bouncing off the walls, floor, ceiling, etc. In the extreme case, if you put it inside a black box with a hotspot, it should receive about 50% of the energy (the other 50% would simply be reabsorbed by the hotspot). That’s 50 mW, so the battery would take about 80 hours to charge, assuming 100% efficiency.

    Are you going to be able to run a blackberry off this device alone? No way. But it may not be as impractical as it appears at first glance.

  97. Maybe if you pooled the energy collected from all 100 devices you might be able to extend your battery life by a few minutes? P.S. Bet my cold fusion generator is better than your perpetual motion machine.

  98. Wow, is this supposed to be a tech site? Some skepticism in the article (even just one sentence!) would have done a lot to save some credibility. Some other posters have already put up the math to prove this is bogus, but common sense should tell you this is too good to be true.

  99. In this thread we obey the laws of thermodynamics!

    If the energy absorber was able to harvest more energy than the wireless source emitted then you could just plug it into the wireless emitter and bam free energy. So either they have broken all the laws of thermodynamics and come up with a product that will completely solve global warming and oil dependency and is the greatest advancement in all science ever or it's a garbage product that does bugger all.

    The maths is right, the device is BS, kudos to Cynake.

  102. Sounds like a con. They prepare a dummy prototype, and make astonishing claims about it, purely to get investment from some credulous investors. After 12 months, they turn around and say “we can't make it work yet; it's going to take more money”. Maybe after years of stalling, they eventually market a product that bears no resemblance to the original pitch.

  104. Wait, what? Yes, the map of electrical and physical inconsistencies is maddening. I think I may finally understand what that whole sceptical revolution is coming from.

  105. I think what everyone here is forgetting is that the number of WiFi signals has little to do with charging capacity. The most important factors are antenna size and conversion percentage, as Cynake has pointed out, even with 100% conversion of WiFi signal to captured energy the device just will not produce the output required to replace the charge in a 4,000 mWh battery in a reasonable time.
    You can direct the output from hundreds of WiFi signals to the antenna in the device but the bottlneck is still the efficiency and size of the antenna.

  106. Fractal antennas use harmonic tuning to up the gain. Of course I think this would be too small of an antenna, even if it were a highly tuned fractal antenna with a reflector.

  110. Yes Daniel Koch from above is right, my math was an order off!
    And Daniel Hall is right too, if we basically turn the whole room/apartment into an antenna, floor and ceiling also if this is an apartment somewhere off groundfloor or top floor, then we would be intercepting all other signals, and only my own wifi signal within the room would be visible to my computer. So my Airnergy would be intercepting 16 signals from all my neighbors from outside, and then my signal from inside to harvest the energy.
    But as per the inverse square law those other neighbors sources would be very low energy; Im skeptical that this thing could recharge its battery in 40 days let alone 40 hours.
    It would be cool to make some wall hanging antennas and just check how much energy i could collect, though.

  112. So I've got this bridge lying around I want to sell…

    OK, so this is a cool idea and an interesting technology, but it's simply not feasible. I agree that it is possible that a small amount of energy could be harvested from wifi signals, but that amount is negligible, and certainly not enough to recharge anything! You'd be better off buying a pack of AA batteries, IMO…/

  114. “So-called physics”!? Ever heard of the law of conservation of energy? An EM wave (suck as a wifi signal) carries a certain amount of energy, and the device cannot possibly output more energy than it absorbs from the EM waves. Before you start being snarky, make sure you are right. If being reality-based is”close-minded” then what's the benefit of being open-minded?

  116. If this could work, why wouldn't we have harvested other forms of RF prior to wifi? What percent of the RF spectrum (energy-wise) is wifi in the average city?

  117. David Sarnoff must be spinning in his grave, so perhaps we can hook his spinning body to a generator and use THAT energy to run a few Wi-Fi hotspots…..

  118. While I agree with most of the math, assume instead you’re only a foot or two away. That ups the value quite a bit. But I think (assuming it’s not snake oil) maybe it’s harvesting more than just Wifi. What if they found a way to apply this to a rather large spectrum of waste energy? Say from 30Mhz to 30Ghz or so? Then you’d be adding some rather large transmitters in the VHF/UHF range, TV, FM, GSM, CDMA… Lots of those signal towers transmit from 50 to 100KW. Add up all the residuals and it may be a reasonable amount, even with inverse square drop off.

    I’m quite confused about someone noting a German law making it illegal to extract power from such things. Upper VHF/UHF energy is strong enough to break through the ionosphere in most cases and make it out to space. Unless you’re directly under a tower a field would not form enough to cause a drain effect. (Like it would putting coils under power lines for example.)

    Personally, I’m betting on the snake oil. But if it’s harvesting a much wider spectrum? It may be able to keep itself topped off, or maybe even trickle charge a small battery inside of a week (being generous).

    I love how people here (and other places) are all about “I could charge my iPhone!”, not realizing all their iGadgets have a non-user-replaceable battery. So, no, integrating such tech into batteries will not help the iCrowd at all. The rest of the planet though, which uses user replaceable batteries, could see a small bump, depending on how close they work to an big transmitter tower. (I work 100 feet from a 35kW VHF transmitting tower, so I’m all for it. 🙂

  121. Back in June Nokia claimed they could get a 5mW charge in a similar manner. It's not too hard to believe that the technology has been improved to the point where at least 20 mW is feasible which is good enough for me since 90% (at least) of the time my phone is in standby anyway.

    Now let's say that only 20 mW will be possible using this technique well here's some math for you all out there. 1 minute of talk time equals 12.5 minutes in standby time (remember that). If you use 200 minutes a month (you may have more each month but studies show most people under use their minutes) that only equals 6.66 minutes a day. Let's round that up to 7 (why? because it makes the math easier lol). Seven minutes of talk time equals 175 minutes of standby or 2.92 hours. Let's round that up again to 3. You with me so far?

    Now let's say you charge your phone once every two days (When it drains completely). All this means is that for every 14 minutes of talk time, you charge your phone for 42 hours of standby time. Now with a 20 mW charge we eliminate the need to charge your phone for all that time in standby.

    Easy to understand right? Let's do some more math. 42 hours multiplied by 60 is 2520 minutes. Divide that by 12.5 to get talk time instead of wasted standby time and you have 201.6 minutes! That's a whole month of minutes! I doubt you'd talk more just because you got more battery life so when it's all added up you'd only need to wall charge your phone only once a month!

    I hope you got all that since i have an easier time understanding math than explaining it sometimes. Also I haven't done any sort of heavy math in like 5 years so my numbers could be wrong. It's up to you to prove or disprove my numbers yourself if you don't feel they add up.

  122. I am not a scientist but you seem not to be considering that power intake and power output are two separate issues. You may trickle charge your car battery, but this does not prevent it from outputing times that amperage to start your car. The point is that as long as the device has harvested(accumulated) the desired power, then it can output it at a rate achieved by the manufacturers. Hope this helps.

  123. You're not taking into account the value of development of this technology. Sure, this one isn't efficient, but in 30 or 40 years they may be able to manufacture devices like this that are cheaper and more efficient, resulting in a new, useful technology.

  125. Think it through. At best, the device could convert 100% of the WiFi energy that would otherwise pass through the space it occupies into electrical energy in the battery. Under anything remotely resembling realistic conditions, that's at most 6mW.

  126. Nokia's claims were not plausible. At least RCA has not make any specific claims to how much energy they can capture from WiFi. I'll bet nobody can replicate Nokia's claims under realistic conditions. As an absolute limit, a device can capture all the electromagnetic energy that passes through the space it occupies. There is a fundamental physical wall here.

  127. Entropy is the disorganization of energy vectors resulting in null space (zero energy). It doesn't mean there is no energy, it's just disorganized.
    There are conditions, like an EMF event, that can temporarily organize the energy into a common vector that can be converted into kinetic energy. This is not limited to WiMax energy, but all disorganized energy, which would explain the “impossibly” fast charging time.

    It's not “free energy” or perpetual motion as such, just an intelligent way to get “work” out of supposed “lost” or “spent” energy. I suspect the WiMax explanation is used to keep the technology from sounding too “woo-woo”.

  129. I solved it for flux through 10cm x 10cm at 1m distance. Assuming a 1w radiator. I also used my 3V battery with 2100mAh (6300mWh). My findings were a little better assuming 100% conversion from radiation to electric potential). I got 3.6 years to charge my battery.

    Again, my WiFi antenna is 1W and I'm 1m away.

    No matter how you look at it, the argument in favor of this device is weak. It's a shame, I thought we would all be living R.A. Heinlein's story “Waldo.”

  131. Acording to the math, it's more effective to include a solar cell in the back of the Blackberry, or maybe the technology of an automatic watch (very small), multiplied.

  132. I believe your math, I really do. But I also believe the ppl behind the device might have noticed something you didn’t and took advantage of it. What was it? I have no idea. And actually, if I had, I’d build such device before them and be rich.

    I find it easier to believe that “you”, internet forum guy, are wrong, then that a big company would risk it’s reputation in the world’s most important eletronic event, by showing a gizmo so “easily” proven unfeasible.

    So I’ll stick with the “I’ll wait and see” stand. Maybe it’s snake oil as some ppl said, but maybe, just maybe, they’ve found a way to make it work.

    Either way, I bet that when Santos Dumont (or Wright brothers if you are american =P) announced he would fly an airplane, a lot of scientists presented very well based formulas to prove it was impossible. Until someone actually did it, and then the formulas explaining how it was possible begin to show up….

  134. Noone mentioned that this is similar to the solar chargers where the real brunt of the utility comes from the charger getting charged by mains or USB or some other such. Of course, a solar cell will be able to harvest much more energy than a wiFi harverster, so in some cases a small solar charger may actually provide a benefit.

  141. So if any device, regardless of feasibility, were to appear at an electronics show you would give it the benefit of the doubt? What if I said my device harvests energy from dead souls near graveyards and brought it to a booth at CES? Would you give me the benefit of the doubt?

    What if the item were cheap, would you buy it on the off chance that it would work? After all, what's 40 dollars compared to the amazing savings of energy out of thin air, right? Well, that's 40 dollars from you, 40 dollars from the moron next to you, etc etc until a company with a completely bogus product has made a nifty profit from something that cannot possibly do what it says.

    It's all about the profit. No company desires ANYTHING else.

    And I support their profit seeking venture, so go ahead and buy one… I won't.

  147. What if the item were cheap, would you buy it on the off chance that it would work? After all, what’s 40 dollars compared to the amazing savings of energy out of thin air, right? Well, that’s 40 dollars from you, 40 dollars from the moron next to you, etc etc until a company with a completely bogus product has made a nifty profit from something that cannot possibly do what it says.

  148. What if the item were cheap, would you buy it on the off chance that it would work? After all, what’s 40 dollars compared to the amazing savings of energy out of thin air, right? Well, that’s 40 dollars from you, 40 dollars from the moron next to you, etc etc until a company with a completely bogus product has made a nifty profit from something that cannot possibly do what it says.

  149. Never enter a Starbucks without a tinfoil hat to save your brain from the radiation!!! Customers in Japan and Europe have been doing so since the early 70s as wifi routers especially back then were notorious for brain burns!! Starbucks in the US has been able to keep people from finding out about this.

  150. I think ultimately Cynake and Rick have it pinned down. There is no practical way this could work. It obviously is better thought out than most “free” energy schemes in that you do end up with a trickle, but not nearly enough to be useful.

  151. Hi There,I am agree with your post.I found this is an informative and interesting post so i think so it is very useful and knowledgeable. I would like to thank you for the efforts you have made in writing this article. I am hoping the same best work from you in the future as well. In fact your creative writing ability has inspired me. Really the article is spreading its wings rapidly…

  153. well …
    like you said its all about profit ..
    and i guess you would make a lot more profit selling normal charger for 20 years
    then selling a non-usable product 6 months and then selling nothing because you ruined your reputation..

  158. oh yeahh,. Am tired of reading all the comment.. I think it would be much more better if I just wrote my opinion in here,….  well ok i’ll say it, i’m no good in math really but I have my common sense with me. first of all, our genius reader had made a computation and they concluded that there is a really a power on those WI-fi signal that could be converted into electrical charges, well that’s good except only on the unthoughtful fact that it takes long for a particular thing to charge and it may even takes  years or decade or century perhaps..
               Boooom!!!!    I have a good Idea why won’t you just study the structure of APC back-up power for the meantime,. at list, you would have something to do rather than proposing the impossibilities base on your calculation…. I also don’t believe in this thing unless I have one :)) toinksss

  159. Obviously junk.  All radios “harvest power” from the transmitter but it’s a tiny amount just enough to communicate information. 

  160. Obviously junk.  All radios “harvest power” from the transmitter but it’s a tiny amount just enough to communicate information. 

  162. I don’t know if it’s really possible and if the profit is more than the loss, but i really think that we have to change the power source of energy. And i think also that capture of wireless wave energy isn’t a real solution. 

  163. Gives you an idea of the level of radiation we are all exposed to even by our WiFi hookups at home. If there is enough to charge a battery then there is enough to screw with our brains. 

  166. His was a bit different. It was technically wireless, yes, but it still relied on the earth as a conductor. It wouldn’t work for something portable like this.

  168. ” if you have a home wireless network you could probably just leave anywhere in your house overnight and it would be pretty close to full in the morning.”

    Or you could turn off your wifi, plug in your phone, and dramatically increase your efficiency. If this works, it only makes sense when you want the wifi on anyway. Leaving wifi on to extract a portion of it to wirelessly charge your phone is not harvesting free energy; it’s waste.

  169. So one quick thought here, if you were in an urban setting you might have dozens of wifi signals you can pick up at any moment. Doesn’t that change the equation?

LEAVE A REPLY