EEVblog #55 - RCA Airnergy WiFi Charging Free Energy Harvesting Marketing BS

Dave can smell marketing bullshit a mile away, so checks out the new RCA WiFi Free Energy Harvesting "Airnergy" device with some back of the envelope calculations. Marketing bullshit or can it actually work?
Can you really charge your smartphone with Wifi Energy?

Watch the RCA video here:

[JonasBygdemo]

To add on to the 10 router discussion: The electromagnetic waves from the routers will most likely be out of phase, and as they meet in space they'll interfere with each other and cancel out at some points (destructive interference) and amplify each other at some points (constructive interference). This means that at some points in space it wouldn't even charge at all, and the theoretical maximum would be your calculated value x10 but it could charge at any multiplicity between 0-10. So you'd have to have A LOT of routers for it to even be viable, but also you need to find the sweet spot to get the highest efficiency every time you charge your phone. I agree, this is absolutely BS!

[Shawn_White]

In another 3 years my cellphone should be charged that'll show Dave.

[EEVblog]

I used to do that but not any more, I don't need more money, I need more free time...
People think working for yourself is great because you don't have a boss, but that is an illusion. You work harder and longer for *more* than one boss, they are called "customers", and they are more demanding than most 9-5 bosses.

[MrCelloman]

I did the math. Charging and iPhone with the power from my wireless router across the house would take upwards of two million years.

[whitcwa]

RCA was once a great electronics company employing thousands of engineers. When they got bought by GE in 1986, the RCA brand name was sold to Thompson, but today its name is synonymous with junk.

[EEVblog]

Money isn't everything, I'd work less hours per week and take a pay cut in my 9-5 job if I could.
I like the consistency of 9-5, knowing that weekends and weeknights are mine, you can forget about the world when you go home.
Working for yourself means if you aren't working your arse off on work, you are trying to find work. The pay ain't as grand as you expect either.
My current job offers many good benefits too.
Money buys you freedom, but it's no good if you don't have the time to use it...

[EEVblog]

If you do get one, post a teardown video or photos!

[EEVblog]

Oh, for sure, there is a huge future in wireless power, and much research being done. It's just in this instance they are stupidly trying to apply very low power energy harvesting to a relatively high power application, so it won't work. But if you put a correctly designed high power resonate induction coil under your desk or in your wall, this type of thing can be made to work. Just not by sniffing WiFi I'm afraid!

[EEVblog]

@Locutus266 No, antenna capture area is square area on the surface of a sphere.

[TypeTuber]

I'm so happy to see someone else that's analyzing this for what it really is. If it was up to RCA all of our car stereo's would feed off the kW FM stations.

I mean just looking at a 10 MHz+ wide Wi-Fi channel you're lucky enough to have enough SNR to get a decent connection.

[sausagedog]

maybe if you stick it in your microwave oven. that will give it a decent bit of power in the 2.4g range.

[EEVblog]

@Zed1967 No it's not, nothing is "stolen" from anyone. If they radiate the energy away then it's your to pick up at no loss to them.

[EEVblog]

@wowerman Because most mobile phones sit flat on desks, ori n pockets or bags when not being used, so the solar cell on the back wouldn't be of much use.

[fredmiller]

Maybe RCA uses gigawatt wifi. Ya' ever considered that?

[Zhab]

Free energy to charge a cellphone ? How about one of those portable flexible solar panels they are selling these days that actually work ? Even if it is not always sunny or even if you live in an area where it rain often a solar panel would still harvest way more energy then this thing could ever dream about.

[wizardofthevoid]

I found this site today, thank you for your informative reviews, it helped me avoid a huge $2K mistake on the TDS2000 series scope with tiny sample memories. On this video I love your very accurate commentary on Corporate Engineering life, "spot on" as you say.

[wilbertbirdner]

you've come a long way in 8 years Dave, i mean who would have thought you would own a real white board!

[unknownpotato]

It still wouldn't work. The issue is not how quickly it charges, but it's the simple fact that there's just not enough energy in WiFi signals to be used to charge the battery with.
Yes, graphene batteries charge much faster because they're supercapacitors, which charges by "directly" storing electricity(electrons); while lithium-ion batteries are only electric cells, which produce electrons through chemical reactions and are recharged when you apply electricity, which will reverse the reaction.

[MrAtheist]

In Germany during DDR-Time the residents near radio-stations "Stole" Energy from the Radio-Waves the transmitter emitted by putting up a dipole with the wavelength tuned to the frequency from the station and were able to operate a little lightbulb from it. But these stations had thousands of watts of transmitting power an therefore it worked pretty well (my grandpa did it too; Yes, I am German).

[aatheus]

What a wonderful piece of literal vapourware! And once the 8 years have occurred, the loss of Li-Ion battery capacity due to calendar aging will make the thing worthless.