back to article The charge of the alternative gadget chargers

Multipurpose gadget power packs provided some welcome light relief at this year's CES. Let's take a look at some of the contenders, real and possibly imaginary. hydrofill Horizon's Hydrofill converts water into hydrogen Hydrofill Horizon Fuel Cell Technologies unveiled an in-home hydrogen refuelling system at the show, …


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  1. DrunkenMessiah

    All very clever and interesting...

    ...but lacking that most crucial of ingredients - none of these are more convenient than a traditional AC power adaptor. Don't get me wrong, I'm all in favour of saving cash (and erm, the Earth) but I'd imagine that the amount of power used by charging my phone isn't really wallet (or planet) shattering.

    Now, your Airnergy working backwards would be a good idea (if workable). A little box plugged into the mains that sends out power to my mobile/laptop wirelessly. That would be worth spending a few squids.

    1. Petey

      or even better...

      Built-in support for Airnergy in whatever gadget you have. That way you reduce the quantity required. The whole point is that the energy is already IN the air. You're missing the point there!

      With respect, m'lud...

      1. DrunkenMessiah


        With respect, I think you're missing my point, which is that I want convenient wireless power and not have to shell out a fortune for it. I get what you're saying, but native support means new devices.

        1. Anonymous Coward
          Anonymous Coward


          No, native support means when a new device ships - it has the tech inbuilt.

          Your current tech won't last forever, so the new stuff should have it?

  2. Rasczak

    Am I the only one....

    ... who, after seeing the image accompanying the miniPAK, is a little concerned about using hydrogen as a power source in mining ?

  3. Lottie


    I like the concept of a Wi-fi energy harvester. It's such a simple concept yet if they can get over the junction gate voltages and whatnot (as I assume the harvested voltage would be quite small) then I reckon it'd kick ass.

    There's also a great market for leasing them out to hippies and technophobes as "technosmog" absorbers from which you can then "empty" every so often and never pay to recharge your mobile/ whatever again!

    1. Anonymous Coward
      Thumb Up

      Re:"technosmog" absorbers

      Charge the technophobes a few bucks for emptying the "technosmog" absorbers!

  4. Andrew Ducker

    Colour me sceptical

    The first one requires you to add water to X, then wait for the water to turn to hydrogen, then plug the hydrogen into something that turns it into electricity. This seems ridiculously convoluted.

    The second one is based on picking up electricity passively from the air. It's going to be _incredibly_ slow to charge, and you'd probably be better off just having a backup power supply.

    The third allows you to swing your battery around your finger. Have we not seen hand-cranked power supplies before? I really can't see this being popular. Again, if you need emergency power then carry a backup battery...

  5. Ian Ferguson

    Clarification please

    "According to RCA the unit can recharge a BlackBerry Bold’s battery from roughly 30 per cent capacity to full in 90 minutes."

    That's pretty misleading. That is how long it takes to charge the phone from the external battery that this device contains - not how long the device takes to gather enough energy from WiFi to charge the phone from 30% to 100%. This is likely to be muuuuch longer - days, I imagine, possibly weeks?

    The little swingy thing probably charges much faster, and from a much more readily available source.

    1. bminish

      WiFi Charger is snakeoil

      The power density of the microwave E/M radiation (Wifi etc) in any place (bar the insides of a microwave oven..) will be several orders of magnitude less than that available for harvesting in the visible part of the E/M spectrum.

      In simple terms power densities at microwave frequencies from Wifi 3G etc will be very very small indeed, thousandths of a mW per M2 .

      Optical radiation on the other hand (Light ) will be of the order of 10's to hundreds of W per square meter. Even comparing the amount of energy to light up a room with the amount of energy required to run a Wireless access point (which typically radiate 30mW or less) should indicate that this 'WiFi charger' is nothing more than snake oil since at best it could only manage to harvest thousands of times less energy from it's surrounding environment than the equivalent sized solar panel would manage

      If it sounds too good to be true then it probably is..

      1. Wortel

        "of the order of 10's to hundreds of W per square meter."

        Hope you brought your sunglasses.

      2. Anonymous Coward
        Anonymous Coward


        "If it sounds too good to be true then it probably is"

        Never a true-er word spoken.

        Although - maybe something along the lines of a kinetic & wifi & solar combination could do something to help keep our power hungry devices charged/last a little longer?

        I know it sounds silly, but tech is getting smaller and smaller/more efficent all the time, so why not combine all 3 into each device. Economies of scale will bring the prices down to silly levels soon anyway.

        Maybe it won't fully charge a device - but just maybe it will let us manage two days charge not the 'norm' of one nowadays?

  6. Filippo
    Thumb Up

    oversized swing

    I propose a bigger version of Swing that works like a hula-hoop. Exercise and power your laptop!

  7. Anonymous Coward
    Thumb Up

    ah good some more useless crap

    I have an idea for a fantastic and freely available new power supply fuelled entirely by pissing into the wind...should I apply for a patent?

  8. Jason Bloomberg Silver badge

    'Ello 'Ello 'Ello

    What 'ave we 'ere then, sonny ?

    At what point does harvesting electricity - from Wi-Fi, broadcast transmissions or any other radiated signal - become the crime of 'theft of electricity' or 'computer misuse' ?

  9. Anonymous Coward
    Anonymous Coward

    Pure vapourware

    especially the hydrogen one. Which is also a very crappy render.

  10. Snert Lee


    So how long would it take the Airnergy to charge up if you put it in a microwave oven?

  11. Anonymous Coward

    Airnergy numbers don't add up

    I don't believe a fucking word of it:

    Maximum permitted output power of 802.11 unit: 100mW

    Approx size of dongle: O(30 cm^2)

    Guesstimate distance from base station: O(100m)

    Ratio of a 30cm^2 patch to the surface area of a sphere of radius 100m = proportion of 100mW available as power to draw from the air.

    Surface area of 100m radius sphere = 4/3.pi.r^3 = 4188790 m^2 =~ 42x10^9 cm^2.

    Ratio of 30 cm^2 to 42 giga cm^2 =~ 7x10^-10

    Therefore maximum power available for charging assuming 100% capture efficiency = 7x10^-11W. Let's be generous and round it up to a hundred picowatts. This is supposed to charge up a battery?

    Did I drop many, many orders of magnitude in my calculations there, or is this about as likely as using pyramid power to charge your batteries?

    1. Andrew Dowd

      Social networking....

      I can just see groups of people clustered around hot spots, jostling for positions to wave their little boxes in the air to gather the 'spare' wifi energy....

      "Surfing the waves man...."

      Business opportunities -

      - an add on market for all sorts of reflectors and collectors to grab 'more' of this free energy.

      - an opportunity for Wfi Hotspot owners to short term lease standing / sitting space around their sites ....

      - I've got a bigger collector than yours, I'll on sell my spare power from over here, see I even have a comfy chair! and a neat bracket you can rest your device in to gather more rays. Would you like a cup of tea??

      mine's the one with the mesh inserts and the reflector in the hood....

    2. Alex 0.1

      Altered figures, still maybe not adding up?

      There don't immediately seem to be any orders of magnitude dropped, but perhaps a couple of incorrect assumptions....

      I would initially suggest that 100m from a base station is an awfully long way, while you're around the home you're looking at more like 20m at the absolute maximum, which is probably also fair for when at your local starbucks / maccy d's / airport / whatever. Assuming being 20m from a base station instead of 100m, instantly increases the potential power charge of the device by roughly 125x over your calculations.

      Additionally, there is no maximum limit of 100mW on wireless devices - 100mW is the most common transmit power for a lot of devices, but plenty of commercial home routers can and do transmit at 24dBm (250mW) and there're ample commercial wireless routers (the kind installed into plenty of larger business premesis) with built in power amplifiers that happily transmit at 26dBm (400mW) - taking 250mW as the max available on a home router, that increases your power availability by 2.5x before taking anything further into account.

      I would also suggest that the large majority of places that have one wifi hotspot available generally have multiple, and as theyre all outputting their signals the device will be able to draw power multiplied by the number of hotspots available.

      I'll leave the rest of the maths up to you (having quickly done it myself it still comes to a piddling small amount of power so there may still also be orders of magnitude missing here, as I can't see any manufacture even trying to punt a device that'd take decades to charge a phone battery) but based on the above i'd say realistically you can increase your estimate on the charging capability by at least 300x, then further multiply that by a potential for multiple hotspots at any one time (granted I live in an apartment building, but i'm currently in range, at various distances, of 9 wifi signals)

      1. Mike Hanna

        Load of nonsense

        Maybe you could have self sustaining power supplies. Like a light-bulb that is powered by solar panels, which it then lights itself, which gets converted into energy, which adds more power to the light bulb, so it gets brighter, which gives more power ot the solar panels, yadda yadda yadda...

      2. Anonymous Coward

        Even with the altered figures...

        ... we're talking about a few dozens of nanowatts.

        >I can't see any manufacture even trying to punt a device that'd take decades to charge a phone battery

        Sure, why not? If Steorn can be trying to sell a perpetual motion machine, why shouldn't RCA be trying to sell us their own variety of snake-oil?

  12. Steven Jones

    Technical gibberish

    All three of these are ridiculously complicated, impractical and surely just spoofs. But then I guess the author of this piece knows that and is just seeing how many people rise to the bait.

  13. Lyle Dietz

    Airnergy could work...

    The assumption being made is that it only harvests from the WiFi bands. What's to stop them collecting from TV and phone bands as well?

    1. Anonymous Coward

      No, Airnergy can't work.

      >"The assumption being made is that it only harvests from the WiFi bands"

      No, dummy, that's not "assuming", that's "reading the fucking article". The bit where it says "Airnergy is described as a “Wi-Fi hotspot power harvester” ", quoting the manufacturer's own description. LERN2READINGCOMPREHENSION.

      >What's to stop them collecting from TV

      Take a look up on your roof. Check the size of the aerial you need to pick up TV signals. Now look at that tiny little box. Does it _look_ like a fucking Tardis?

      1. markp 1

        so near, but...

        I agree with the spirit of your post, but not the technical detail.

        Take a look in argos and see how many handheld TVs there are that you can buy. They work. I got one yonks ago (about 15 years?). The aerial is the same as you'd get on a cheap painter's radio. The size of the rooftop aerial is a mystery to me - it must be because it then has to shunt the collected signal down 10+ metres of cable of indeterminate quality and age or something. That or the little handheld telly is spending much of the power coming out of it's battery pack on boosting the signal. But then again my LCD widescreen is already chucking a 5V (and lord knows how many amps) boost through the aerial cable and it's not doing much good for freeview.

        Still, harvesting all the TV, radio, and other frequencies is a good idea, particularly at night when you can't use the otherwise many-magnitudes-more-effective solar power. Or you have the device in a pocket. It could also feed off mobile phone towers. Limiting yourself to noticably weak wifi signals is a bit silly and probably a lie. Same as those "wifi/phone microwave detectors". Yep, ok, you've managed to detect *some* kind of minuscule signal then amplify it out of all proportion, well done you. I then turn round to the people proudly showing it off and say "I've got one of those in my living room, it's called a TV... and another i can carry almost anywhere in the world and still get a positive result, it's called a radio... how did you think they worked?" (not to mention a Dangerous RF detector that works everywhere for 12 hours of the day on average - a solar calculator)

  14. Rattus Rattus

    What's the point of the hydrogen duo?

    First device to convert power to hydrogen, second to convert hydrogen to power. Why not just make one device that you put the batteries into which then directly charges your phone/DS/whatever? Why involve the water and hydrogen and all that in the first place?

  15. John F***ing Stepp

    Free energy (snicker)

    I plug my rechargeables in at the office.

  16. TeeCee Gold badge

    I think there's a problem.

    I've put some water in a "special collection canister" (I used a plastic cup with a saucer on the top to stop the Hydrogen getting out) and I've left it on my desk for an hour now.

    It still hasn't turned into Hydrogen. How long should I wait?

  17. Anonymous Coward
    Anonymous Coward

    Bloody simple solution

    Make all chargers and devices compatible. Simple.

  18. Kurgan

    Wifi charger, uh?

    Oh my god, this is the crappiest thing I have ever seen. Supposing that it could actually work and collect enough energy, it would obviously remove such energy from the EM field that makes wifi work, so basically if everyone had one (or more) of these things, wifi transmitters would need far more power to work, because their signal would be absorbed by all of these power vampires along the way from the transmitter to the receiver, like if there were concrete walls all around the transmitter. Not really useful, don't you think?

    An yes, you could use GSM signal, TV signal, or whatever signal you like, but:

    1- you need a different antenna to tune in at different frequencies, so there can be no "catch-all box"

    2- you still receive far too little energy to use it

    3- you still weaken the EM field, making the mass use of these devices disruptive

    And remember that the energy and pollution needed to build such a charger are tipically more than the energy and pollution that such a charger can save.

  19. Anonymous Coward
    Anonymous Coward

    PEM (Proton Exchange Membrane.)

    whiole the hydrogen Hydrofill could do with some work, dual collection use cylinders, to keep the flow going and limit the actual stored hydrogen to a safer limit per canister, and allow you to buy more cylinders for dispersed storage, much like a smoker wil have several gas lighters around, etc.

    it seems several people dont quite get it, its all about Actually Generating Your Own Supply of fuel directly for your PEM (Proton Exchange Membrane.)

    ,not relying on the mains, or 3rd party suppliers for your end user supply just to power a low power CPU device or two for the few hours per day or more.

    after all its not that hard to make distilled water if thats what it uses for its cell use...although that to could be included in to a self contained power unit able to power a low power 6v Arm A9 , a low power 12v LCD, and your 5v wireless router for instance...

  20. Anonymous Coward
    Anonymous Coward

    Altered figures, still maybe not adding up?

    "Alex 0.1 Altered figures, still maybe not adding up?"

    thats because your not thinking simple existing tech added to this initial current

    the simple generic step UP Transformer in miniture versions however you like ...

    see for instance

    Resonant Charging Choke Concept

    all these things are nothin greally new, only thing changed is that Now We actualy have low power CPU SOC devices that can run off these lower initial currents TODAY....

    its a shame idustry have not seem fit to put onboard your average family sized fridge.freezer, LCD HDTV etc a generic 12v DC low current input to their power curcuits etc..., perhaps this year might be the year.... if we get standardised 10 amp + fuel cell and related miro power generation for the home, then we might get somewere..

    1. Anonymous Coward

      No you scientifically and numerically illiterate perpetual motion believer...

      ... you do not get any more power out of the step up transformer than you put into it in the first place, so however much power you get out of the air, that is still exactly how much power you can get out of the air.

      >"We actualy have low power CPU SOC devices that can run off these lower initial currents TODAY"

      Yes, you half-clever idiot. So what? Current is not the same thing as power.

  21. Anonymous Coward
    Thumb Up

    Sir Humphrey Davy the 'Scotch Davy' lamp


    Am I the only one.... #

    Posted Monday 11th January 2010 16:42 GMT

    ... who, after seeing the image accompanying the miniPAK, is a little concerned about using hydrogen as a power source in mining ?


    ohh dear, history and science classes in Uk schools are so bad these days it seems...

    namely the "'Scotch Davy'" gas miners safetly lamp.

    basicly a gas light lamp encased in a fine metal mesh, if it comes in to contact with gas

    in a an enclosed space such as a mine the gas can get in through the mesh and so

    ignite that small amount inside the mesh as it comes into contact with the flame,

    HOWEVER, the resulting explosion CAN NOT get passed the mesh to the outside.

    "... thoroughly efficient safety lamp is not a mere mechanical contrivance for giving light in

    a coal mine. It is an instrument con­structed in accordance with established laws of physical science. It ensures the burning of a protected flame in the presence of explosive

    gas, by regulating the necessary supply of atmospheric air, and by allowing the products

    of combustion to pass through without igniting the gaseous atmosphere.

    If the atmosphere is so heavily charged that noxious gas enters the lamp, its presence

    will be indicated by a change in the length and color of the flame, and (unless there are

    exceptional circumstances), the miner has sufficient warning to secure his safety.

    The principles on which a thoroughly efficient safety lamp is constructed are practical, not theoretical...."

    Fuel Cell (FC):

    "A fuel cell transforms energy electrochemically. In a controlled fashion, without the use

    of an open flame, a fuel cell converts the chemical energy stored in fuels like hydrogen,

    methanol or methane, directly into electric energy. This is the reverse of the electrolysis

    process. In addition to electrical energy, fuel cells produce water and heat as well. "


    Color- and odorless gas. Hydrogen is the smallest and lightest element on the periodic

    table. A hydrogen atom consists of a negatively charged electron and a positively

    charged proton. Hydrogen is the most abundant element in the universe. However, due to

    its high reactivity it is mostly found in compounds, including water (H2O), hydrocarbons

    (e.g. natural gas, which is mostly methane (CH4)), or crude oil."

    So in effect If you were wise as to put in place an extra safetly feature, them you add in a 'Scotch Davy' lamp style mesh into your final Hydrogen supply cylinder PEM device insuch cases, simple.

  22. markp 1

    i can't be the only one...

    ...wondering how the hell the hydrogen thing works, can I? Hydrogen + Oxygen -> Water is an energy releasing reaction, so you have to put energy in to seperate them, even with the world's most effective catalyst. Basic chemical physics. So where's it coming from in the "hydrogen generator"? You're going to have to put in more than just water - whether it's electricity (plug in, solar, turn a dynamo handle...) or some kind of renewable chemical supply, powdered, liquid or solid. Probably in the form of disposable packs that you buy at the shops and plug in the bottom of the device.

    Funny, I can buy something like that at maplins. A box that you put disposable chemical packs in, a universal cable that clips onto it, and interchangable ends that you plug into your phone (none of this messing about filling it up with hydrogen like it was a bloody ciggy lighter). You don't even need to add any water, just the small, cylindrical packets, which make the energy out of nothing but air. I like to call them Alkalines...

    We've been over the Wifi charger nonsense, so onwards. My money's on the spinny thing. It could be quite a therapeutic effort charging it, something you can do almost as an idle tic. I certainly know of the habit from rewinding tapes with a biro in the days when my only player was a five quid walkman with only stop, play, and so-called "fast forward" that was the same as play but without the head and capstan slowing the tape down. Want fast wind? Pop it out, thread the pen through the appropriate sprocket, and make like a 1970s footie fan.

    My now several-years-old wind up torch is still going great guns with nary a change of battery or trip to the wall socket, and it can even charge my phone (or would if i hadn't lost the cable down a gutter in Edinburgh). If you had a protracted call to make, or a long walk ahead, the winding could get tiresome, but for short bursts, hunting for stuff in the garage or calling the emergency services it's just fine. Something which fits better in the pocket and has less easily losable bits - and can be wound one-handed, which is the major problem with most dynamo gear on the market right now - could be a winner.

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