EEVblog #55 – RCA Airnergy WiFi Hotspot Energy Harvesting Marketing BS
Dave can smell marketing bullshit a mile away, so checks out the new RCA wifi Energy Harvesting “Airnergy” device with some back of the envelope calculations. Marketing BS or can it actually work? Watch the RCA video here: www.youtube.com
Tags: Airnergy, Back Of The Envelope, Checks, EEVblog, Energy, Energy Marketing, Harvesting, Hotspot, marketing, New Energy, Rca, WiFi, Wifi Hotspot
February 7th, 2010 at 9:36 pm
Very nice video! I feel like the world of electronics is allready too much smoke and mirrors.
I do think there are a places where we can benefit from wireless energy transfer(electric toothbrush, maglev) but these will always be specific applications.
Another company that is maybe a little bit more realistic is powercast. they employed it for a wireless charged sensor. Too bad they market it as wireless charging of consumer apps. I don’t think that it will contribute to a sustainable future…
February 7th, 2010 at 10:05 pm
Microwave ovens are everywhere though. I think they are right about 2.4 ghz. I’ll suggest that to anyone that buys one of these gadgets.
Love the video.
February 7th, 2010 at 11:01 pm
Yep, will do, still sorting out a new mic.
February 7th, 2010 at 11:21 pm
Great video as usual, Dave. I did the same sort of ballpark calculations when I first saw the Airnergy thing. And I too called Shenanigans!
As a suggestion, can you increase your video volume a bit, I need to turn up the youtube player, and the OS volume controls to max to hear you. I’ve noticed this on multiple computers.
February 7th, 2010 at 11:30 pm
Never mind ´regular´ people. I cease to understand how geeks (supposable extra I.Q.) can go for this. If there is WiFi nearby there is also a power outlet! Duh!
February 8th, 2010 at 12:18 am
Very true, should have put more thought into that before posting really. Something like this was on Mythbusters IIRC. And like I said why don’t they just stick a solar panel on it – you’d get far more energy from that – provided it’s not kept in a pocket that is!
February 8th, 2010 at 12:58 am
If you want to pick up the maximum of energy from a frequency, you have to build your antenna so that it interacts well with it, which means that it must have the same resonant frequency. The problem is that a good resonance gives a narrow sensitivity peak. Other frequencies go right through it. If you try to widen the frequency range, you need to lower the efficiency at the peak. They probably picked 2.4GHz because there is more energy than at other frequencies (still not much).
February 8th, 2010 at 1:46 am
Sorry not enough room in one post. Some ‘fast chargers’ only apply the stage 1 charge so the battery is about 70% charged when it’s finished so you don’t get full capacity but having a Li-ion battery at below 100% will actually make it last longer (get more cycles out of it).
February 8th, 2010 at 2:29 am
What I said about Li-ion charge rate isn’t strictly true – they aren’t just charged at a constant current like Nickel batteries normally are. Instead they are charged at a high current for about the first third of the charge (about 70% charge level) then the current drops off slowly as the voltage limit is reached – the topping charge. Charging at a higher current for the first hour or so just makes the topping charge longer as the voltage limit is reached more quickly.
February 8th, 2010 at 2:59 am
Ah, yes, people do like delusions!
February 8th, 2010 at 3:18 am
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…
February 8th, 2010 at 4:10 am
Wow, I never thought about it as working for “many bosses”. Good insight. But, in the end, working for yourself allows you to remove that income limit and your limit is only set by how much work you put in as a consultant. The extra effort of having many clients is not worth the money?
February 8th, 2010 at 4:43 am
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.
February 8th, 2010 at 5:29 am
Dave, do you do any consulting? Would you or have you ever considered going into business for yourself as an engineering consultant? I’ve read about the headaches, as you’ve described in other videos, of working in the corporate world. If you worked as a sole business owner, you could focus on your talents without all the corporate b/s, no? Would you recommend it to others? What’s the business like as a consultant?
February 8th, 2010 at 6:18 am
Dave you forgot to calculate the people intelligence, by the area, is like religion it doesn’t have to work you just have to believe it does. The problem is you are too smart, and you want reality and not a fantasy like 90% of the people in the world.
February 8th, 2010 at 7:05 am
Why not use the unit together with your lunch in a microwave-oven
Indeed complete BS. Dave great blog always waiting on the next one.
February 8th, 2010 at 7:59 am
RCA is nothing but a label. Thomson Consumer Electronics is the corporation that own,s rca name and many other’s. I’ve had my run in’s with this outfit with their prduct’s before. Enjoy you’r informative vid’s Dave.
February 8th, 2010 at 8:16 am
I did a quick websearch , and from comments on forums around the net you can see ppl bying into this bullshit.
Only about one or two in ca 10 comments are sceptical.
We`re surrounded by idiots !
February 8th, 2010 at 9:09 am
I guess that was MY idea :p
February 8th, 2010 at 9:45 am
I think the fillings in my teeth collect more energy from cosmic rays. I’m off to patent the idea so that in the future, when we work this out properly I can make loads of money
February 8th, 2010 at 10:40 am
Oh yeah, for sure – my main point was I couldn’t see a microwave charger being useful. I was referring to currently available batteries when I was talking about charge rates. And as I said supercaps can be charged in a matter of seconds but aren’t mainstream yet.
February 8th, 2010 at 10:54 am
@SomeMoreVideos2468 For example take a look at Toshiba’s SCiB. They claim 90% charge after 5 minutes at rate 12C or 90% after 10 mins at 5C. It should be available next year. Not targetted at mobile handheld devices though.
Li-Poly for RC models can be charged in about 1 hour and stays cool (I have one)
I don’t say it’d good to charge your phone in microwave oven, just that these fast charging batteries exist and there will be more in future. Li-based chemistry is still in heavy development.
February 8th, 2010 at 11:40 am
Yeah and what confuses me about this is why would they tune it to 2.4GHz – why not just pick up all RF? I mean it still wouldn’t be enough to do much but it would be better than form just 1 frequency. You’d get more energy by sticking a solar panel to the back of it!
I wouldn’t like to have enough RF around to power a phone or something – your body is very effective at picking it up too!
February 8th, 2010 at 11:47 am
Oh and one more thing – I don’t have a slow charger – a C/3 charge rate for Li-ion batteries is a rapid charge. My point is that there really isn’t any point in charging something from a microwave as it would be expensive, inefficient and would probably just damage your microwave oven because of arcing since very little of the ~1kw of microwave energy would be picked up by the antenna. Supercaps are emerging which can be charged in a matter of seconds but my point still applies…
February 8th, 2010 at 12:04 pm
Yeah the 15 minute charger was for NiMH which can be charged that fast but it’s a totally different chemistry. Li-ions would just explode if that much current was forced through them. Most Li-ion batteries have a maximum charge rate of C/3 but smaller ones like those used in mobiles can sometimes be charged at up to 1C. ATM there’s just no Li-ion batteries in production which could support such a high charge rate but even if there was – why not just use a charger for them??