RCA announces WiFi-sucking battery
The RCA AirPower series of emergency chargers use surrounding WiFi signals to charge their internal batteries.
Yes, you read that the right way round: a WiFi-powered battery pack. Dubbed the AirPower, at first RCA's gadgets - previewed over on LoopyGadgets - appear to be normal emergency power supplies for your portable gadgets - and that's pretty much what they are.
Where the technology gets interesting is in the power source which charges the internal battery: rather than relying on being plugged into a USB port or a wall socket, the AirPower - as the name suggests - draws power from thin air in the form of surrounding WiFi signals, which are converted to a current powerful enough to trickle charge the internal battery.
While the technology potentially means never having to plug the device in, the low power of WiFi signals means that it takes a while: RCA claims that the internal battery takes a full six hours of exposure to a strong WiFi signal in order to fully charge.
RCA's implementation of the energy-harvesting technology comes just a few months after Nokia predicted its own variant - designed for embedding directly into a mobile 'phone handset - would likely take five years to become a commercially viable product.
Although pricing information has not yet been made available, RCA is hoping to release the product in the US before the end of the year - and hopefully we'll be seeing a UK launch in the near future, too.
Are you impressed at the thought of an emergency charger which never needs plugging in, or would you need to see the technology in action - and the potential effects it may have on your WiFi signal strength - before getting excited? Share your thoughts over in the forums.
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Discuss in the forums ReplyWhich uses more power? Using a cable for (say) an hour during the day, or leaving you're wifi on all night? I usually turn it off if I don't need it as my main PC uses a wired network.
I guess if you have wifi at work then someone else would be paying for it.
I would certainly prefer this than a charging mat or USB, it means you can just leave your phone around the house and it gets charged.
But yes it will terribly inefficient, but phones use no power anyway so the cost would be nothing per year.
Lots. ^_^
I wonder if regular radio-waves can't be used.
Here's something that might make you reach for your tinfoil hat: wifi uses a frequency extremely close (within about 50Hz) to the magnetron in a microwave. Actually, you probably don't want that hat as we all know what happens when you put tinfoil in a microwave ;)
Now, we do not live in a perfect world. Your router is almost certainly not high powered operating at 1 Watt, and this devices ability to charge your battery is also not even close to 100%, and the device is not capturing your entire WiFi signal.
Assuming that the receiver has a surface area of 400cm^2 (10cm by 40cm).
And you place your laptop a meter away from the router.
And you have a high powered 1 watt router.
And we live in a perfect world where everything has perfect efficiency and the receiver's normal is directly pointing at your router providing maximum surface area.
Only about 1/314th the energy from the router will get to the laptop. This is a little over 3mW. It would take about 20,000 hours to charge a 60WH battery. Enjoy using your laptop for 2 hours every year.
This is precisely what I was thinking. And it can't be argued that it could charge a mobile phone, either: phones use more than 3mW while sitting idle, so you wouldn't even be able to keep an idle phone from discharging with this tech.
I'm going to go a step farther and question the integrity of RCA all together. Every house has a 40W light bulb, incandescents are about 10% efficient so they are radiating 4 times as much energy in the visible spectrum as the most powerful routers and we already have devices to capture this energy called solar panels. Now, if you tried plunging in a small solar panel on the back of your laptop and said it would power it, most people would find that absurd. But when you are using invisible radiation from routers, people have absolutely no idea how little power it is.
I can see this potentially being useful in one of those backup batteries, you can just leave it in your bag and it keeps itself topped up. No more than that at this stage, and not for a primary charging mechanism for a long time/if ever.
"draws power from thin air in the forum (should this be form) of surrounding WiFi signals" :)
There's about 15 trillion trillion neutrinos going through your body every second. But like wifi signals, are completely harmless. Brainiac did a nice experiment to prove this - they got 100 mobile phones around an egg, and got each one sending/recieving microwave radiation. Did it cook the egg? No. Such low power.
Scaremongering comes from those who just do not understand and think scientists are all evil and live in volcanos *cough*Daily Mail*cough*
However, I'd prefer this tech in the equipment itself, and charging mats to put the device onto, as previously suggested.
Uh, 100 phones times 2W = 200W which isn't enough to cook an egg, but it would certainly have heated the egg up.
Radiant energy decreases at a rate of distance squared. You could have 24 routers 5 meters from your laptop and they still wouldn't provide the power of the 1 router a meter away that would take 3 years to fully charge a laptop battery.
aww man, i was going to post the math. good job ;-)
i would like to point out, though, that you assume the router is a zero point emitter. in actuality the router would emit it radiation along the whole length of the antenna, so the power is already diffused right from the start. ordinarily assuming a zero point emitter is perfectly ok, since the length of the antenna is insubstantial compared to the distance traveled, but when you are talking a broadcast distance of one foot, and an antenna length of 6 inched it become a significant source of diffusion in the equation. . . . of the top of my head i would say reduce you figure by about 50% for perfect physics land, depending on your orientation to the antenna. factor in inefficiencies and your figures could be high by an order of magnitude or more.
then there is the issue that those devices look to be about 4x8 cm (for a total area of only 32cm^2) and you have a device that probably only provide picowats of power at any distance farther away than "taped to the antenna" distance. and that is in the best case scenario of being perpendicular to the emitter. that may or may not be above the self discharge rate for a particular battery, so this may not even be able to keep an *unused* battery topped up. . .
yeah, this tech is nothing but hype marketed to unknowing consumers. it does not even constitute a source of "emergency power" since it provides such a small amount of energy. the only thing it might be able to do, and that only if you leave it next to your router, is keep an already charged batter from self discharging. if you keep it in a handbag and expect it to do anything measurable you are dreaming.
@eddtox
the only signal that should be affected is the signal in the "shadow" of the device. if the device is between your router and your laptop i would expect you would see very little signal strength, since it is being eaten by the charger.