Airnergy Charger device charges your phone using Wi-Fi

Usually, enabling Wi-Fi cuts into a device’s battery life. RCA hopes to turn that concept on its head with the Airnergy Charger, a device that purportedly captures the energy from stray Wi-Fi radio waves and stores it in a battery.

The folks at OhGizmo! got the spiel about the device. On the CES show floor, the Airnergy Charger purportedly managed to charge a BlackBerry Bold smart phone “from 30% to full in about 90 minutes, using nothing but ambient WiFi signals as a power source.” An RCA executive shows off the device and provides a little more background information in the following video:

OhGizmo! says the initial version of the Airnergy Charger pictured above, which has a built-in battery and what looks like a Micro USB connector, will become available this summer with a price tag of just $40. Not bad, but RCA has bolder ambitions. In the video, the executive says RCA intends to miniaturize the device and stick it into batteries next year. Those batteries should be priced competitively with plain phone batteries.

If you think this all sounds too good to be true, well, you’re probably not the only one. Still, if RCA isn’t smooth over any major caveats, then getting more mileage out of one’s laptop or phone might soon involve embracing, rather than evading, the warm glow of Wi-Fi access points. Just hope you’re not allergic. (Thanks to TR reader Brian for the heads up.)

Comments closed
    • LaChupacabra
    • 10 years ago

    Witchcraff.

    There, I said it.

    • thermistor
    • 10 years ago

    #10…Faraday cage match!!

    • Welch
    • 10 years ago

    My thoughts and im sure most of you are thinking the same way is not to worry about plugging your phone into another lame charger, but to get the components small enough in the base of the phone that you don’t have to switch batteries out. Using an EXTREMELY low powered sensor to detect if wifi is up, then it can turn on its Wifi receiver to accept the Wifi signals and convert it into energy. Instead of making this a “Ohh its dead, plug er in” it would instead extend the battery lifespan of your phone because it will charge as you use it normally. If it manages in a few days to even charge by say 50% then you effectively got a time and a half of your usual batteries life. Battery preservation and if all else fails, backup charger..

      • SomeOtherGeek
      • 10 years ago

      Now that is a thought. Anything to save electricity! Use the wifi to charge your phone. Seriously, the phone is used maybe 30% of the time, right? So, the other 70% can be used for charging.

    • wira020
    • 10 years ago

    Perpetual Motion machine!!! OMG! Btw, sounds neat.. just hope someone could really study the effect of excessive wireless signal in a home setting.. kinda worry me a bit… i’d prefer my baby out of radiation possibility…

    Call me old school or anything, but i havent yet found any proven study on how these signals affect babies… i’d just like to be sure…

      • djgandy
      • 10 years ago

      You should worry more about that great big thing in the sky that provides you with light every day.

    • MadManOriginal
    • 10 years ago

    What things like this really need are very wideband antennas that way they aren’t limited to certain small and low powered frequencies. It is possible to make very small wideband antennas.

      • ludi
      • 10 years ago

      Depends, is it more efficient to make a wideband antenna and grab a little of everything, or tune the antenna for a known frequency?

      • SomeOtherGeek
      • 10 years ago

      Right. Why only WiFi? Anything that has a wave is a form of energy, right? So, why not get every piece of it. TV, radio, RF, even light and tons more.

    • ludi
    • 10 years ago

    What do you want to bet that the mini-USB connector is the “auxilliary charging method” for the integrated battery, which will in fact charge from ambient WiFi signals but takes a week or more to fully run up the battery under its own power?

    Looks like nothing more than a universal spare battery pack with a ThinkGeek-esque twist.

    • Asbestos
    • 10 years ago

    Listen! Do you see that? I smell BS.
    My Linksys WRT54G is broadcasting at 42mW. At a 30 foot range an antenna of the size shown would be receiving much less power. Good luck charging anything but the salesman’s brain with that. I can only imagine that the antenna must be placed directly on top of the wireless router to have any chance of charging a battery in a reasonable amount of time.

      • BoBzeBuilder
      • 10 years ago

      This.

    • ApockofFork
    • 10 years ago

    Just threw some numbers into a google calculator. This doesn’t make sense at all. Apparently the average hotspot has a signal strength in the .1 watt range(20 dbm). This is a decent amount of power if it was actually going straight into your phone. However no matter what system they’re using it couldn’t possibly be more than 10-20% efficient like the other wireless power companies are claiming. Some are claiming higher but only in very controlled situations like placing a charger on a charging surface.

    All of that is null and void though if you actually think about what happens to that .1 watt. It gets dispersed spherically so that the power at a radius r from the origin is split over a surface of 4*pi*r^2 meters^2. This little pack looks to have a cross section of about 10 cm^2. So even at 5 feet its only gobbling up 10^-5 of that power or in terms of your cellphone’s power consumption, nothing. So this tech will either require the receiver to be placed right next to a hotspot or will be totally useless for even cell phones.

    If you look at other wireless tech, they’re even trying to power ultralowe power usage devices like embedded sensors which use a couple of orders of magnitude less power than a cell phone or they pumping a lot of energy through the air in a very, very controlled way. Wifi is neither of those things. Good bye funny little startup.

      • NeelyCam
      • 10 years ago

      WiFi antennas don’t transmit spherically – usually very little power is transmitted up and down. Note also that signals can bounce off the walls to some degree. It’s not like this thingy needs signals to be in phase or coherent in any way.

      Moreover, I think the idea is to charge the battery at all times, and then plug it in and charge up the phone. Basically the energy harvesting only needs to provide enough for cell phone stand-by needs.

      That said, this doesn’t seem plausible… Nanowatt stand-by is still a few years away…

      • designerfx
      • 10 years ago

      give it a while, everywhere else I read said this thing is pure BS and unrealistic.

    • lilbuddhaman
    • 10 years ago

    question:
    In say, your generic starbucks, you have something similar to this covering the walls of the store, or strategically placed in different “high signal places” in corners and whatnot…

    Would this then allow a store that has “free wifi” to confine their signal to within their store AND get a power return ? Or would placing something like this on the walls degrade the signal within ?

      • Heiwashin
      • 10 years ago

      You could just as easily use a faraday cage or such build that is much simpler to accomplish the same thing.

        • Majiir Paktu
        • 10 years ago

        Where I live, the buildings are all built with chicken-wire in the walls. Talk about wireless hell.

      • WillBach
      • 10 years ago

      You can use antenna arrays to direct signals, and I think that multi-antenna routers use that to focus the signal towards active receivers

    • ew
    • 10 years ago

    It certainly is effective at charging up my BS detector.

    Seriously though, what is the maximum output power of 802.11? How long does it take to charge it’s internal battery? How much of the BlackBerry test was from the internal battery vs WiFi.

    • MadManOriginal
    • 10 years ago

    It’s not too good to be true or unbelievable although the specifics of charge time might seem so. The downsides I can see are if it is not able to be turned off you’ll always be degrading the WiFi signal that you actually want to use. Probably not a big deal in a home setting but imagine every person in a public place with WiFi having a device or two with such a battery.

      • adisor19
      • 10 years ago

      I don’t think you understand the principle behind it. The device is just a wifi antenna connected to a DC converter and a battery. Any antenna tuned for a particular frequency will have the airwaves induct and as a result, will produce a small current.

      If there is wifi activity around, it will charge. Obviously, it works much better when it’s really close to an active wifi transmitting device.

      Since the whole point of this device is to absorb energy, it doesn’t transmit anything and it doesn’t degrade wifi signal transmission unless it’s placed DIRECTLY in the line of sight and very close to a real wifi client radio.

      The idea isn’t new. It’s rather old actually. Nicola Tesla had great plans to distribute electricity wirelessly back in the day.. unfortunately, the wifi singal is not being broadcast using magnetic resonance so there is a LOT of loss. Also, the power levels drops at the power of 2 as the distance between the 2 antennas increases linearly.

      And one last thing, wifi power levels are pathetic! around 50mW on a small 2.5dbi omni directional antenna..

      Adi

        • MadManOriginal
        • 10 years ago

        Yeah I don’t know why I neglected the fact that a device’s antenna only receives the waves that hit it, it doesn’t pull in more transmission power than what it can receive.

          • Anomymous Gerbil
          • 10 years ago

          Well, that’s a given.

          The real point is, the power available to a small antenna at any reasoanble distance from a wi-fi transmitter is so small that it’s just not going to be practical to charge a phone battery in a sensible amount of time.

            • Skrying
            • 10 years ago

            Will it be pulling from only one WiFi network? A single access point? Go into a city (or hell, even downtown in a small town) and you’ll pick up tons of WiFi networks. It could add up to usable power.

            • Palek
            • 10 years ago

            Everybody seems focused on access points. What about WiFi enabled laptops/netbooks and phones? I realize they would be transmitting at even lower power levels, but it all adds up.

        • djgandy
        • 10 years ago

        Indeed. WiFi relies on a lot of reflection. The signal you get is a tiny fraction of what is transmitted.

        How much energy is left after the signal has bounced off 3 walls?

        Sure you can place the receiver right next to whatever is transmitting, but why not just plug it in to that device? The transmitting device will have power, so there is a much more efficient method of getting power close by!

    • cegras
    • 10 years ago

    Conservation of energy. You’re going to be leaving a cone behind you void of signals.

      • Contingency
      • 10 years ago

      Inverse square law. What happens to the rest of the energy? What percentage of total energy is fed into a receiver?

        • cegras
        • 10 years ago

        Not sure, but depending on the geometry of the transmitter, you, and some hapless victim …

    • Construct
    • 10 years ago

    the initial version of the Ainergy Charger pictured above, *which has a built-in battery* and what looks like a Micro USB connector.

    The built-in battery is responsible for charging the BlackBerry Bold from 30% to full in 90 minutes. The real question is how long it takes for the device to harvest stray signals and charge the internal battery.

      • NeelyCam
      • 10 years ago

      ^ +1. This does sound like a great idea, though, if the energy harvesting rate is good enough.

      Then again, if it is, why not just integrate this into the phone without the extra battery?

        • cygnus1
        • 10 years ago

        That’s what the article says they intend to do. To sell batteries with the tech built in so you can replace your current battery with one that auto-charges from ambient radio waves. I fully expect that if this technology works as advertised (which I’m very skeptical of) you’ll see a lot of device manufacturers start including these batteries.

          • Anomymous Gerbil
          • 10 years ago

          No.. to integrate the charging tech into the phone, not the battery. Although whatever way it’s done, it’s rarely going to be much of a help, given the low wi-fi power strength.

    • BoBzeBuilder
    • 10 years ago

    Sounds to good to be true. Battery problem solved?
    Will this slow down my internetz?

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