State of Wireless Charging in May 2019

I have to apologize for the low rate of postings - basically I'm slammed with work, personal ventures, and home/family. I'd like to be writing more, and talking about what I'm doing, but that's just not going to happen for a while. Hopefully more at the end of the year, but for now I'll use the long weekend to try and get at least a couple of articles done.

AirPower and Qi

My last article on wireless charging, noting the disappointment of AirPower and PiCharging (Spanse), got some mixed responses. Some industry insiders were not pleased with my portrayal of Qi as limited, and suggested that if I were to review a premium phone with the associated official charger that I'd have a different opinion. I agree that in a perfect world Qi can achieve some reasonable charge rates, however my hope for AirPower was that Apple removed the need for consumers to worry about positioning and would make it a seamless experience. Just "drop and go" and it's charged when you pick it up an hour or two later - but they couldn't do so. 

The problem isn't Qi's performance under ideal conditions, it's that if you need the ideal setup, a premium phone, and the expensive charger, then many users get a sub-par experience and then that experience taints things from there on out. You don't want consumers to think it's pointless? Give them a great experience first time out, and then that becomes the expectation and when there's a cheap knock-off charger that's $50 cheaper but charges at 1 W not 7.5 W they blame the cheap charger, not Qi. Let there be a tainted ecosystem where for years it's a crap shoot how things go then the standard gets blamed instead.

The reality of things is that consumers are dumb, and will take the cheapest and laziest route on everything. For example, I went to Amazon and typed "wireless charger Pixel 3" and I see the official Google wireless charger for ~$80 (4 star review) and an LK charger for $16 (4 star review). I understand this stuff and can't tell what the difference is, the average person has no chance. I have no idea if LK is any good or not, but is it 5x better than the Google? That's the price point most people expect, and are going to have a hard time justifying that extra $64. Now does that $16 charger work fast and well, or does it fail to charge due to positioning on a regular basis, or charge slowly? (I'll try and let you know in a few days, I just ordered it) If it fails on even a couple occasions and you lose phone use during the day because it didn't charge overnight then people start to default back to "just plug in with the wire that came with the thing". For the Pixel 3 that wire is an 18 W charger, and that's noticeably fast.

So can Qi be great when all is good with the setup? Yes. But if a consumer has to know the exact setup to use to get that then the $16 base unit sets the expectation, not the $80 one.

Update 28th May 2019: A reader tells me "The reason it (the Pixel Stand) costs $79 is not because it charges faster or with more placement forgiveness than some 3rd party charger like LK (although it does offer a proprietary 10W mode, so it should charge a Pixel3 somewhat faster than LK). Rather, the 'Google Screen' feature is why it is priced very high.  You need to use the Pixel 3 phone to unlock this feature, but it is really cool, IMHO... To simply take some Samsung or Apple phone and compare its charge rate on the Pixel Stand vs. the LK and obviously conclude that it is not worth the extra $64 is a waste of time and misleading." Seems a fair point, and I do have a Pixel Stand on the way too, I'll compare them in more than just the charge rate. Still, I had no idea there were even such features in the stand so I think my point on poor marketing of what may be excellent features stands!

It was also pointed out to me that what I was saying about the frequency of operation didn't make too much sense, which on rereading was a fair point. What I wanted to say came over badly, and there was no easy way to fix it, so I deleted it. Thank you for that feedback those who sent that comment.

Pi/Spanse and Qi

So this was the more interesting one, it seems. I had pointed out that I had thought Pi would be a success in part due to the use of the existing infrastructure of the inbuilt Qi charger, but that I was now confused as they talked about the need for a proprietary charging case didn't go down well with users. 

When I had written the first Pi article, I'd seen the original paper on the technology working at 6.78 MHz, and spoken to a couple of people I knew and trusted who had connections to the company and the answer came back "yes they shifted to 140 kHz". I also emailed the founder and specifically asked this question though didn't get a response (should have raised a flag there). I then went on to write the article based on that, and there's a lesson here for me in not believing something until I've seen it in verified. I think someone should start a blog about that...

Well suspicions now seem to be confirmed. If you go to Spanse's website you can see the "Source" that they are now essentially selling is a large Qi charging station that works with up to 6 devices and thick cases, for $189. Sure you get wifi for updating and a USB port for wired charging, but I've already got that in my laptop, or a wall socket, for a lot less. Now personally I don't have 6 devices that need charged, and I'm wondering if it's 12 times better than that LK charger I just ordered. It seems a bit large for bedside table use, so is it aimed at a kitchen table for a family, or an office? The generic image above shows it charging an iPad, but look closely and you'll see the iPad is wired charging, and given either the wall socket the Source is plugged into, or the laptop nearby, could have done it I'm struggling to see the clear use case. 

Importantly, the at-distance part is gone. What exactly happened is unclear, but rumours seem to be that the near-contact Qi charging was conflated with the at-distance charging that would need a proprietary case and a higher frequency. People I've chatted with who have some connections call it an honest mistake and miscommunication, but if true then I'm calling bullshit on "honest mistake" when the key aspects that made this interesting happen to not be true. Everyone knew what people wanted, and it was the convenience of modest charge rates at a modest distance, with pre-existing charging infrastructure. Add in the requirement of a new expensive case, and it's just another also-ran.

Ossia

Ossia (wireless charging with RF, very similar to Energous) announced a deal for wirelessly charging IoT asset trackers in Walmart warehouses. 

...guards and associates will wirelessly power the asset trackers at warehouses’ guard shacks, ensuring the trackers are charged before they’re attached to incoming trailers, crates, pallets, and packages.

While the wording in the article seems to be ambiguous and points to also charging the handheld devices the employees use, I expect that fundamentally this is using their 2D array to locate and charge the small low power trackers that go on boxes and pallets in warehouses. Given that active RFID work at up to around 100 mW in short bursts (from recollection), a high microWatt, low milliWatt source that saves employees a minute on each tag across thousands of tags will be economically viable. From what I've seen, this is basically Powercast's business model and they've been out there for years quietly serving the market without the fanfare or exaggeration of Ossia or Energous.

Interestingly the Ossia VP interviewed talks about the "proof of concept" which makes me wonder if this is just a demo for Walmart and not an actual sale/rollout. Regardless, this very low power, intermittent need, in an industrial facility, which is the kind of thing that wireless power at-a-distance is actually suited for. It's one of the reasons all the companies talk about charging your phone fastert than a wire at multiple meters, but then move to "trickle charging" and then IoT, and then eventually out the consumer space entirely. All of them. No surprise, it's where they all inevitably go after having exhausted all the alternatives (and investor money).

Energous

Very briefly on Energous - I wondered if they would make their raise given the price of the stock, but it seems they did raise a further $25m from stock, and so now have cash to make it to early Q1 2020 assuming no reduction in staff or compensation. (I was told they had trouble selling that, cancelled the first offer and tried again, and ended up getting it from a short seller group, which is ironic. I have no confirmation on this, so take it with a pinch of salt) This still isn't enough to see them to revenue, given their own statements as to even the best case for products, so we'll be back here at the end of the year with the same thing again. We're also still waiting on any products with "WattUp" in them, such as the hearing aids (sorry, PSAPs) that were promised in no more than 90 days about a year ago. Don't hold your breath on those products.

Lastly, investors seem to be catching on, and share price for WATT has dipped and is now around $4.55. Tracking the stock price for the last year, it's not looking good for them. At what point do the institutional investors realize they've been had and bail?

uBeam

Last and definitely least, uBeam. So little going on here compared to the others, Ossia and Spanse at least have technology that can sell even if it's not a wow, and Energous are quite entertaining, but what is happening with my former company? They're continuing to be fairly low profile, as they (presumably) try to package up IP and at least pretend there's a workable product in there somewhere to either licence or sell the company. 

I took a look to see if there had been any IP filed - generally you see what got filed about 1 year or more ago, and can tell what the company was working on at the time (not 100% certain, sometimes you still patent dead end paths). I was quite surprised by what I found looking at their filings. Now it's often hard to tell what are applications, what are grants, and what are just repeats in the system, but when you see that the most recent patent (10,252,908) was submitted in Feb 2018, that almost all the people listed on it had left the company 1 to 2 years prior to it, and that my name was one it as well, you can tell they're really not producing much new. In fact, going back through them I can see one other that was filed in 2018, and that's also from an employee who left in 2016. Maybe I'm missing a trove of them at the USPTO, but it looks like the bulk of the filings come from people who were there in 2015 and not much beyond. How do you sell a company based on IP when you've not produced new IP in years, the people who did produce that IP have long since left, one of them writes a blog criticizing you, and there's no product?

It seems that uBeam might now hire a third person since their (supposed) $25 million fundraise over 14 months ago. This time, it's a Chief Commercial/Revenue Officer.

uBeam is seeking to hire a Chief Commercial Officer/Chief Revenue Officer. uBeam is the inventor of ultrasonic power-at-a-distance Always-On Wireless EnergyTM, utilizing ultra-safe ultrasonic array technology to deliver reliable, long-range wire-free charging. By developing proprietary transducers, transmitters, receivers, and custom enterprise software, uBeam’s technology delivers usable power to devices ranging from portable electronics, medical, aerospace, automotive, and in particular IoT devices and networks. Significant revenue-generating experience in these fields, coupled with successful B2B licensing experience is essential. Experience in acoustic technology, phased array radar or ultrasound is also highly beneficial.

So "Always-On Wireless Energy" is their new tagline I guess, since it gets a 'TM', although no-one bothered with a superscript. Apparently the technology is not just safe but "ultra-safe" which I'm not sure the definition of but given the emphasis here, they must be feeling a bit of vulnerability on this front. I don't follow why a C-level "revenue" officer needs to have tech experience but bizarrely they want someone with "significant revenue-generating experience in these fields" and I'm not sure who that could be because quite literally no at-distance wireless power company has ever done that - not Energous, not Ossia, perhaps only PowerCast that actually have had a product on sale for a while.

Lots of references to dealing with board members in the ad, as well as fundraising. "The CCO/CRO will be required to present to the Board of Directors on a regular basis, and from time to time will be involved in fund-raising activities on behalf of the company.", "Successful experience in fund raising and pitching to investors.", "Have considerable experience presenting at Board of Directors meetings.", and "Ability to efficiently interact with board members."

It's a bit odd to be looking for a C-level hire via regular job board postings, those are mostly done via word of mouth, personal connections, and specialized recruiters. As someone on the EEV Blog pointed out - sounds a lot like the role a CEO should be doing. Is the uBeam CEO looking for a scapegoat already, or is this a replacement?

Phrasing also indicates they're aiming for markets outside the US, which on the one hand you can understand because the professed model needs contract manufacturers which are still heavily in China, but given every other country outside the USA definitively has a 115dB or less ultrasound limit (1000x less power than at the professed 145dB), the product is not viable there unless they ignore the law. "Experience in dealing with issues on an international basis: understanding of the North American and European landscape (knowledge of the Asian market would be a plus)."

As far as I know, this is a new position, so not from the Perry era and gives a confirmation to the business strategy the company is taking - B2B licensing, with contract manufacturers, and keep it going long enough to bamboozle for another round of investment.

Oh and apparently "Benefits that are 2nd to none!". Yeah, I'm going to call bullshit on that. How much PTO? How much in RSUs and bonus? Sabbaticals? Educational supplement? Matching 401k? My recollection (and that of more recent departees) is good benefits for a startup, but can't match that of larger companies.

Last thing for this article - uBeam don't post much on social media like LinkedIn so it was interesting to see them link to this safety article from the CTO of Wi-Charge (laser based power delivery). 

Forbes just put out a good new article on wireless charging. Wireless Charging can take on many forms, but not all of them are safe and effective. uBeam's ultrasonic wireless power is a differentiated technology that can safely transmit energy over the air across long distances to charge a wide array of electronic devices. 

The premise of the piece was on regulatory and safety aspects of wireless power, yet uBeam used it to claim safety for their own system. Now we don't know what uBeam have (cough), and they do claim "third party testing" has proved it safe, but never released those reports, despite questions on how they can do what they claim at 145 dB when it exceeds sound limits around the world. For those wondering about various limits, I have a list here.

I have to wonder - do they know and know they are lying, do they deep down suspect and are avoiding checking so they can pretend to themselves they aren't lying, are they just that dumb, or are they true believers? The psychology of this is fascinating, as perhaps each person pretends it's not their responsibility and keeps cashing the paycheque. I really want to find this out someday, sadly I think it's just going to be one of those mysteries.

Powercast and Ossia

This blog spends a lot of time covering Energous, the RF based at-distance wireless power company, as in my opinion it's such a good example of how to manipulate the press, public, and markets with not much more than great PR and a willingness to be 'flexible with the truth'. In their own little world there's some competition from other companies essentially doing the same thing, in a technical sense. The most prominent of these are Ossia and Powercast.

I've been asked a few times about these companies and why I don't really cover them, and the basic reasons are these - they've not been blatantly lying about technical capabilities (to date, read on for some concerns), deliberately creating multiple product lines to confuse media and consumers, or funneling money from the general public straight into the pockets of the executives. There have been enough questions though that I wanted to clarify who these companies are, what they offer, and the (minor) technical differences between them and Energous.

Powercast

Powercast have been in operation since 2003, and have had an at-distance RF based wireless power system available and FCC approved since 2010. Like Energous they operate in the ~913MHz band, and the physics involved is essentially identical. They have a number of patents in the area. You can actually buy development kits to test them out, their website has detailed technical datasheets on all products, a simple but realistic spreadsheet for calculating actual power that can be delivered. The datasheets make it clear that they should be useful for wireless sensors and low power electronics, and never mention phones, tablets, TVs, cars, or any of the other ridiculous items other wireless power companies talk about. They don't spout techno-babble about "energy pockets" that they can't deliver on (like Energous' demonstrated inability to accurately focus in their FCC Part 18 filing).

The two product lines for receivers state up to 100 mW for the short range (over 2 days to charge a phone), and 10 mW for the long range (nearly 3 weeks for a phone), and that's maximum. More realistic is 1/10th of that, and that's reflected in the Powercast descriptions of 'microWatt to low milliWatt' levels. Powercast products are FCC Part 15 approved, which is the same rules under which your WiFi router operates - yes, it's that kind of power level we're talking about here. Could they get FCC Part 18 'unlimited power' certification? Yes, I think they could, and they might up their power output by a factor of 2 before all sorts of other safety limitations kick in. In practical terms Part 18 would buy them limited benefits with a number of restrictions, though clearly from the Energous buzz around their Part 18 approval it's worth a lot marketing wise.

So what does Energous have that Powercast doesn't? In my opinion basically nothing, except a marketing department willing to push the boundaries of truth, and an FCC Chairman willing to use his public position to promote a private company. Powercast appear to me to be a genuine engineering company, following all the rules and regulations, that has a product that you can buy, and are completely upfront and clear as to the technical capabilities and limitations. 

They may not have a desperately useful consumer-level product, but that's not to say it does not have its application. With regards to phones, if someone like Apple had wanted to, they could easily have made an offer that Powercast couldn't turn down and incorporate this tech into their equipment. But they didn't, and is a firm and clear datapoint that RF wireless charging isn't really viable in the consumer space. Powercast's website lists a number of design wins that may well have specific demands that make the technology appropriate for that case. I can see it being used in industrial settings, charging large numbers of extremely low power sensors in awkward to reach locations. They mention RFID on their site, and it seems like a good fit for those conditions. Use of this technology may also grow as the number of "Internet of Things" devices increase.

In my opinion, Powercast should be commended for sticking to an honest approach to their business in the face of what must be incredibly frustrating marketing and publicity from Energous. Like many engineering led companies that focus on delivering a product and not on marketing hype, their approach probably gives them a good business but fails to deliver them the riches that the less scrupulous get. The price of a conscience?

Ossia

Ossia have been going since about 2008 and are still privately held, having raised at least $25 million from industry and Venture Capital groups including Intel. Their technology, which they brand 'Cota', is also RF based, but this time at 2.4 GHz, same as some WiFi routers. Their founder/CTO writes blog posts and technical white papers available from their website, but they are exceptionally light and free from any real information with which to analyze their products in detail. There are no products, datasheets, or evaluation kits of Ossia technology that I am aware of. (Update, In June 2019 Ossia received FCC Part 18 Approval for a system.)

Their choice of 2.4 GHz results in a smaller wavelength than the 900 MHz band (around 12.5 cm vs 33 cm), so in theory can lead to greater control over small focal zones and beamforming. At best the focus will be at least a phone sized sphere in any practical situation, but it's better than the beachball sized 'pocket' Energous have. By creating a large phased array of many small transmitters, and sending the right signal to each, a beam could be steered with reasonable precision - their 'ceiling tile' size array (pictured above, from here) could have 10 by 10 emitters each spaced at half a wavelength, and according to this article is closer to 16 by 16, so 1/3 wavelength spacing.

Larger arrays mean greater control, I covered some of the maths behind this here. Ossia claim this allows them to be much more precise in targeting the receiver, and 'bounce' signals around the room so that direct line of sight isn't needed. The image below from Ossia shows this in operation, with the receiver sending out a location signal about 100 times a second. This is a pretty well known engineering technique, sometimes called time-reversal, so under the right conditions it will work. It does not, however, reduce the size of the smallest possible focal zone, remove safety limits, or increase the amount of power legally transmittable.

Under Part 15 rules, Ossia can still only transmit as much power as Powercast, which means the entire system is just a more precise way of delivering microWatts to low milliWatts and leaves phone charging as an impossibility. Much of Ossia marketing material in the last few years has made it clear they're looking at similar low power situations as Powercast. Their statements are sometimes questionable, for example that 2.4 GHz is 'safer' than 5.8 GHz, can allow more precise targetting, and won't interfere with WiFi. I wonder if they'd say the same now that Energous have moved from 5.8 GHz to 913 MHz?

What about Part 18 and 'unlimited power'? There's no reason that Ossia can't do this, and once again will be limited not by transmit power, but the various safety restrictions, which like Powercast means perhaps a factor of two increase in power delivered. Why haven't Ossia done this, as it's not a complex set of tests to go through? While the FCC have not made specific statements on this, it seems they are unwilling to give Part 18 certification on wireless power devices in the 2.4 and 5.8 GHz ranges. Energous started at 5.8 GHz, but rapidly moved to 913 MHz when they repeatedly failed to get FCC approval in 2017, skipping 2.4 GHz entirely (there are limited frequency bands that are available in Part 18). 

One school of thought is that the FCC isn't allowing Part 18 at 2.4/5.8 as they are the main WiFi bands, and that communications will suffer interference, so the options left are 913 MHz and ~25 GHz. Another is that the FCC isn't allowing 'unbounded' energy above a certain level - that you need control of that region of power, a peak with clearly defined edges. This would mean charging would have to happen within the near field, or at best at the near/far field boundary. No matter what your technology, that is set by the laws of physics - basically your frequency and size of transmitter are all that matter. Bigger transmitters are less practical but will allow you to push that boundary out further. Higher frequencies lead to more precise control over the beam and spot due to the smaller wavelength, as well as more transmitting elements in the same space leading to precision.

While Ossia have been playing by the rules and not putting out highly misleading marketing, I've been disturbed by some of their recent press. This article looked at both Ossia and Energous, and reached the usual level of in-depth analysis by a tech journalist that I'm used to (i.e. none). At first, Ossia demonstrate a transmitter with 10 Watts of output power - that's clearly well beyond Part 15 limits, and matches the 10 Watts of the Energous Part 18 transmitter.

"The maximum range is somewhere around 30 feet, but at that distance you can only receive a very small amount of power. Within 6 feet of the transmitter, you’ll get somewhere around 1 watt from the 10 watts being transmitted. At longer distances, you might expect 100 or perhaps 200 milliwatts, which isn’t enough to charge up a smartphone, though it can slow down the discharge."

Since they don't have Part 18 approval, that device needed to have a clear notice that it was not FCC approved and is not available for sale. I wonder if they had it and the journalist simply failed to notice? I also find their numbers disturbingly high - remember Energous transmits 10 Watts to get 30 mW at 90 centimeters, are Ossia really getting 33 times the power at twice the distance? That implies some massive directionality and antenna gain, and regions of space between transmitter and receiver going well over safety limits like SAR and MPE.

They then go on to talk about safety:

“We have established that this technology achieves the same level of safety as Wi-Fi and Bluetooth, so there is no issue with exposing people.”

This is bordering on deliberately misleading, having talked about the power levels with a non-approved device, (which seem to be vastly beyond anything realistic even under Part 18), to then go on to talk about safety numbers from WiFi type equipment of Part 15. Poor journalism may be to blame here, but I don't see Ossia rushing to correct it. I've refrained from talking about Ossia too much as they had not been making outrageous claims, or deliberately confusing the press and consumers by talking about two very different products in subsequent sentences, and allowing the listener/reader to assume they are the same. If they keep this up, in all fairness to Energous, I'll need to start covering them in the same way. Ossia, please don't make me do that, I've little enough time as it is to write...

Summary

There are at least two other RF based wireless power companies out there besides Energous. One of them has had an approved device on the market for years, but has minimal traction in the consumer market. The other seems to be trying a more technically sophisticated version of the same thing, but are now watching Energous getting away with very misleading marketing. Both are limited by the laws of physics, and safety rules, that mean powering phones or any other sizeable devices is out of reach. Despite that, tech journalists will continue to publish puff pieces on how wireless power for phone charging is just around the corner.

I can't blame companies who follow the law from trying to get favourable coverage. The tech press, however, need to wake up to the fact that they are now reporting on products and markets that directly affect our health and safety. Despite high profile cases like Theranos, it seems to be business as usual. The usual cursory coverage and regurgitation of company PR doesn't cut it in these situations, this isn't the latest iPhone or a dating app, and they need to step it up before something hurts more than investors wallets.