I'm having trouble believing that RCA's Airnergy, a "WiFi hotspot power harvester" unveiled at CES, can actually charge its internal battery from WiFi radio signals.
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.
A commenter on OhGizmo! offers the following:
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.
(BTW, What is that dent in the gadget about? Looks like someone poked it with an awl.)
RCA Airnergy Charger Harvests Electricity From WiFi Signals
Withdrawn by Samsung and recalled from store shelves, the explosion-prone Galaxy Note 7 is now forbidden in the skies. The Federal Aviation Administration has officially banned it, via an emergency prohibition order, making it a federal crime to take one on board an airplane. The order restricts passengers from carrying the phone “on their person, […]
Beam is a lightbulb replacement that screws into any light-socket and turns it into a remote-controlled LCD projector.
There was a time when I had a lot of multitools: it started innocently, with a classic Leatherman “pocket survival tool,” which I carried everywhere, and because when you have a multitool, everything looks like a screw, bottlecap, thing-in-need-of-sawing/scissoring, or filing, I used it all the time.
The Atmos R2 may be bigger than the brand’s previously-released vapes, but we argue that in this case it’s definitely a good thing. A bigger heating chamber means more room for packing it full. And the bigger battery means longer, more fulfilling vape sessions. In fact, you can use the Atmos R2 for up to about 25 […]
These days, there is huge demand for ethical hackers. Companies pay these professionals to identify and remedy security holes in their networks before malicious hackers find and exploit them. What’s great about this is that if you love hacking or think you may love hacking, you can do it for a living and not as […]
The Boing Boing Store features tons of headphones with a range of functionality, quality levels, and prices. Today we’re featuring 2 of the best additions, fresh to the Store this week.The first set of bluetooth headphones are great for working out or everyday listening, while the wired second set will be really attractive to anyone who […]