The charge of the alternative gadget chargers
Hydrogen and Wi-Fi used to power tech
CES 2010 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.
Horizon's Hydrofill converts water into hydrogen
Horizon Fuel Cell Technologies unveiled an in-home hydrogen refuelling system at the show, enabling portable consumer gadgets – including mobile phones – to be repowered using hydrogen.
Simply fill the company’s HydroFill unit with water, screw a special collection canister into its middle and the device will fill the canister with useable hydrogen in around 60 minutes.
HydroFill works by breaking water down into oxygen and hydrogen, with the latter filtered into the canister to provide the power of up to eight AA batteries.
Canisters then slot into Horizon’s MiniPak – a mobile phone-sized unit that re-charges portable electronic devices over a cabled connection.
Hydrogen canisters from Hydrofill slot into Horizon's MiniPak gadget charger (above)
Horizon hopes to launch its in-home hydrogen power system this year.
RCA has designed a handheld gadget capable of turning wireless signals into gadget-friendly power.
Airnergy is described as a “Wi-Fi hotspot power harvester” and measures roughly the size of a 3G dongle. The gagdget simply takes free energy available through Wi-Fi hotspots, converts it into DC power and then stores it inside an internal battery.
RCA's Airnergy turns Wi-Fi into usable power
Airnergy passes power to gadgets over a USB connection. According to RCA the unit can recharge a BlackBerry Bold’s battery from roughly 30 per cent capacity to full in 90 minutes.
Last up is Swing. Just a concept for now, and maybe a concept forever, the credit-card sized unit generates power by being swung around your finger like a pair of keys.
Designers Teaho and Lee were light on technical details, though we presume the 3.7V battery would generate power through some form of kinetic movement.
Gadget power with a few spins, anyone?
Around 130 revolutions would provide enough power for two minutes of banter on a mobile phone – that’s if Swing ever makes it into production. ®
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?
Free energy (snicker)
I plug my rechargeables in at the office.
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.
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)
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?