wireless charging (eg, Qi) - slow adoption? - Page 1
Forum section: electronics / general

author: linux-works
author_rank: Super Contributor
timestamp: June 20, 2015, 03:45:08 am
content: how well is Qi being adopted by vendors and consumers? is this the format that 'won'? when I search for 'wireless charging' on, say, amazon, I only see Qi results.I do get lots of results and lots of $10 class charging pads, and also, now, $10-20 credit card insert things that have the receiver chip and coil and either tap into the battery contacts or connect to the micro usb connector via flex pcb.BUT - when I go out to stores, even here in silicon valley, I don't see much at all for Qi. went to frys today (pretty big and somewhat famous electronics chain in this area) and they had a samsung charger for $40 and some used POS for $80 (!). that's it. radio shack, what is left of them, had the same samsung pad, also $40. went to an office supply store and the guy knew what I was looking for but almost laughed since its 'too high tech' for an office store (he said).could not get anything locally. sure, some phones are now coming with qi coils in them but I'm not seeing pads in the stores and I'm not seeing stores showing much interest, either.a friend tells me that 'its already a market failure'. I'm not sure I agree as I kind of like the idea, but when I went out looking for stuff, I found next to nothing.what's your experience with current product and/or implementing with it? I'm thinking of trying to use it in a project I'm working on but I'm brand new to this wireless charging stuff. are there compatibility issues out there? do all the chips work with each other? is the standard 'finished' or does it really need more work? any insight on this would be appreciated. and if its not all its cracked up to be, I'd also like to hear that before I spend a bit of time and money on it.

author: poorchava
author_rank: Super Contributor
timestamp: June 20, 2015, 08:27:23 am
content: I think wireless charging was not very well received, and but have no idea why. Everyone I know who has used this technology seems very happy with it. For some reason though very few (if any) new devices support it without additional accessories like the aforementioned add-on cases and flst-flex antennas. Silicon vendors have some pretty good solutions. I've even see an TI chipset that they claim can deliver over 10W of power (although this is outside of Qi specification)Sent from my HTC One M8s using Tapatalk

author: electr_peter
author_rank: Unknown
timestamp: June 20, 2015, 08:38:36 am
content: I consider wireless charging to be a niche sector for consumer market. Market failure would be too strong word to describe the situation. It is relatively expensive, advantages show up only under certain conditions (you still need wired charger, wires and base station to use it, charging distance/position has to be exact for it to work at all). Qi is effectively the same as old cell phone/PDA charging docks/stations (device sits in the dock, makes contact and charges) which was not very popular as well.Also, only the most expensive phones have it built-in, so even less consumers know and would like to use such "flashy toy" like function. I have tried it but do not like it too much - I do not need extra wires and devices consuming space and outlets all the time (I prefer to use charger when needed, otherwise store it in a drawer).In short - with Qi charging you have to spend additional amount of money just to get very similar result of regular cheap charger, so I just do not see it as a popular technology in a consumer market.I had issues with cheap Qi transmitters/receivers, but I would consider Qi as an option for some electronics devices where physical separation or "invisibility" of wires is needed. You can build you own custom charger to suit your power/distance/efficiency requirements as well.

author: Psi
author_rank: Super Contributor
timestamp: June 20, 2015, 10:01:33 am
content: I got a random Qi charger for my LG G3.It doesn't work reliably, it starts charging but always seems to abandon the charge some time later, which makes it uselessI should have got the official LG Qi charger

author: saturation
author_rank: Super Contributor
timestamp: June 20, 2015, 12:51:56 pm
content: I experimented with several Qi chargers for a month but even with its current version, the inductive losses were high and lost as heat, being very problematic.Passive cooling at 25oC ambient it would reach 40-50oC. In the winter at20oC ambient, it reached 35-40oC. With a fan, it would hold under 40oC.Transfer efficiency was 70-80% at best, and position sensitive. If you use a cradle to lock in coils sweet spot instead of a formless pad or platform, it works best. Alas at worse, my phone would signal OK to its position at 50% efficiency.I monitored charger output with a ammeter/power meter and the phone's via a power and temperature monitor app. I also double checked the temperature via IR thermometer.Big problems:My phone has charge temperature protection, and at times the phone terminated charging due to heat rise, further lengthening the charge time, and we are not yet in the peak of summer temperatures.The battery was never fully charged relative to direct cable charge, even with the phone powered off, and even if the phone signaled full charged in about 6 hours, I left it trickling for a whole day. At charge termination, the battery would rapidly drop from 100-90% in a 2 quiescent hours. On an optimal USB charge, it would still register 99%.On a USB charge, the phone never exceed 35C with passive cooling.While I can tolerate the charge inefficiency, in general heat is a killer of batteries. At over 35oC, cycle life is reduced [ my projection] , charge retention is reduced [ likely demonstrated, as it never fills completely].

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: June 20, 2015, 01:03:14 pm
content: A problem is that charging is limited to about 500mA, when the norm nowadays is often 2-4x that.One area it is handy for is charging sealed devices, but you really need a charging cradle that holds everything in good alignment

author: amyk
author_rank: Super Contributor
timestamp: June 20, 2015, 01:14:28 pm
content: Having a cable plugged in is better as you can move the device around and otherwise continue using it while it charges.

author: fubar.gr
author_rank: Unknown
timestamp: June 20, 2015, 05:06:49 pm
content: As already noted, wireless charging is full of drawbacks. It's only good for the uber lazy who can't be arsed to spend half a second to connect a damn cable. Nothing more than a gimmick.

author: linux-works
author_rank: Super Contributor
timestamp: June 20, 2015, 05:27:53 pm
content: Quote from: fubar.gr on June 20, 2015, 05:06:49 pmI just got a set of parts to play with (mail just arrived)at first test, it looks good, actually. but time will tell.I bought these to try out:https://www.amazon.com/gp/product/B00MN3RR7Qhttps://www.amazon.com/gp/product/B00HJ2KEMQa very low-priced base (which has mixed reviews) and a very low priced receiver coil 'card'.the card is nice. it fits perfectly in my ancient android phone and also fits perfectly in my portable audio player. it does eat up a micro usb port and on my audio player, that is a problem since the usb port can be used for charging as well as OTG usb mem sticks for extra storage. might see if I can tap into the power leads directly and save the usb port for data.the pad is big which I like since you don't have to balance the charged device on a tiny little puck.also tried the adafruit coil unit and that seems to give me exactly 5.00 volts (on my fluke) when I sit it on the charging pad. here's the adafruit diy card in my hand, for size comparison:soldering 2 wires to the bottom 2 pads does give me that 5v as it should.as for being lazy, its not always about that. samsung, for example, has a known history of their usb ports being somehow different from many cables. lots of direct experience with this (I used to work at an android tech company and lots of peoples' samsung phones would not charge with micro usb cables that worked for other phones). the micro usb port is better than mini usb but it still can fail and it does on lots of devices.wires are annoying. I converted to a cordless mouse over a decade ago and never went back to a wired mouse. wired keyboard, ok, but mouse moves around and is natural for wireless.same with small devices. I want to be able to pickup and use the phone for a bit but then put it back down and have it resume charging. why deal with cords when you can pick it up, use it, put it down and there's no tangle? seems like a total win to me, as long as you are not in a hurry to get the device charged. if its always left on the pad, its always catching up and at least not draining the battery, as is the usual case when its not connected to a charger of some kind.I'm going to give this tech a few months testing to see how it works out and what issues I'll find over time. but so far, I really like the idea, at least.

author: linux-works
author_rank: Super Contributor
timestamp: June 20, 2015, 05:30:00 pm
content: Quote from: mikeselectricstuff on June 20, 2015, 01:03:14 pmif I needed a super fast charge, yes, I'd go wired. of course.but if a trickle charge is acceptable, then charge speed is not an issue. in fact, charging slower is better for the battery in every case.I do agree about the cradle part and I may build one to work with the device I'm designing. that way they are aligned together by design. so far, though, the 2 pads I bought are not critical about alignment and I'm able to see the device immediately go into charge mode, not even caring what the base's light has to say.

author: Sigmoid
author_rank: Frequent Contributor
timestamp: June 21, 2015, 01:18:12 am
content: Quote from: poorchava on June 20, 2015, 08:27:23 amIf the first thing you can think of about a new technology is "it's cool but... why?", then it's kinda doomed. Why would I want wireless charging? It's quite thoroughly pointless. And do I want even more EM radiation in my living space?

author: nctnico
author_rank: Super Contributor
timestamp: June 21, 2015, 01:54:38 am
content: Quote from: Sigmoid on June 21, 2015, 01:18:12 amThose are good questions. IMHO the Qi standard is rather over engineered (as usual) and the power levels are very low. What I'm seeing is that wireless power is very interesting for applications which (for example) need a high voltage isolation barrier (tens of kV) or cannot use connectors (under water). However in those situations a full Qi implementation is just overkill and the required power levels are usually much higher.

author: Psi
author_rank: Super Contributor
timestamp: June 21, 2015, 03:43:37 am
content: The thing that annoys me is that once the phone gives up on the Qi recharge a few times it doesn't seem to try again until you remove it and put it back down.So you put it on the charge pad and it begins charging just fine, then a few min/hours later while you're asleep it decides to abort charging and you wake up with a phone that isn't full.

author: andtfoot
author_rank: Unknown
timestamp: June 21, 2015, 04:22:58 am
content: Quote from: Psi on June 21, 2015, 03:43:37 amI can't say I've ever that issue. I'm using a Nokia Lumia 930 and Nokia charging pads.I have a charger at home and at work; I find it handy to able to just drop the phone on the pad when I sit down, and grab it when getting up to walk away.I've never had to resort to charging from the cable, unless I'm interstate or something (where I charge from my laptop I have with me anyway).

author: Psi
author_rank: Super Contributor
timestamp: June 21, 2015, 04:32:59 am
content: maybe its just my crappy 3rd party Qi charger

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: June 21, 2015, 08:10:36 am
content: Incidentally if you want to add Qi charging to your product without the gamble of using no-name Chinese receivers, TDK do an OEM module :http://www.digikey.co.uk/product-detail/en/WRM483245-15F5-5V-G/445-16097-ND/4702663

author: EEVblog
author_rank: Unknown
timestamp: June 21, 2015, 08:14:59 am
content: Everyone is waiting for uBeam

author: Galenbo
author_rank: Super Contributor
timestamp: June 21, 2015, 08:28:58 am
content: Could be a good thing for dust/waterproof devices. On my S7710, like on every other S7710 phone, the rubber dust/water cap broke off after some weeks.

author: andtfoot
author_rank: Unknown
timestamp: June 21, 2015, 08:32:25 am
content: Quote from: EEVblog on June 21, 2015, 08:14:59 am

author: zapta
author_rank: Super Contributor
timestamp: June 22, 2015, 05:48:34 am
content: Conductive wire free bases can provide higher power and at higher efficiencyhttp://www.pcmag.com/article2/0,2817,743234,00.asphttp://www.gizmag.com/review-wildcharge-wireless-power/13186/

author: Gribo
author_rank: Frequent Contributor
timestamp: June 22, 2015, 06:50:15 am
content: My experience with Qi chargers: Most are crap, the ones that use the IDT chipset are the worst. The better ones use the TI chipset and reference design, along with a decent coil, however, most OEM don't bother tuning them for maximum performance. The same happens with the receiver, TI based devices have generally better user experience than IDT based devices, and on the receiver, tuning is far more critical.

author: Mr.B
author_rank: Unknown
timestamp: June 22, 2015, 08:20:21 am
content: Quote from: fubar.gr on June 20, 2015, 05:06:49 pmI totally disagree...I am not lazy and it is not a gimmick to me.I have a Samsung Galaxy S6.I have a genuine Samsung Qi charger base for it.Before I go to bed at night, I simply drop it on the pad as I send the dogs off to bed.I don't need to pay particular attention to alignment... somewhere in the middle is good enough.Next morning I have a full battery ready to go for the day...Great concept as far as i am concerned.Oh, and by the way, my micro usb socket will not wear out as I don't plug it in every night...

author: Jeroen3
author_rank: Super Contributor
timestamp: June 23, 2015, 09:00:15 am
content: There are two scenarios where wireless charging becomes interesting imho.- Fully enclosed waterproof devices. Such as diving gear, smartwatches and waterproof phones. (Why do you even need a waterproof phone? For "entertainment" in the shower?)- Batteries that charge in a few minutes. Just put the device on the charge pad for a few minutes and it's fully charged.Where wireless charging does not have any direct benefit on your nightstand. The device has the full night (5+ hours, for most people) to charge. Wireless will only introduce unnecessary loss. And unnecessary electromagnetic interference of which we still aren't 100% sure it's safe for humans. Also, unconnected phone chargers cause enough standby load to have a significant accumulated loss. Wireless charges will only make this worse.It might also be of interest in things that have to recharge A LOT of times. Such as in-flight entertainment pads. Or Lasergame backpacks.But it is financially more interesting to swap the battery-pack.

author: Sigmoid
author_rank: Frequent Contributor
timestamp: June 23, 2015, 02:21:38 pm
content: Quote from: Mr.B on June 22, 2015, 08:20:21 amI have an iPhone and a wall charger.Before I go to bed at night, I simply plug in the Lightning conenctor and send the dogs off to bed.I don't need to pay particular attention to alignment, Lightning is robust and reversible.Next morning I have a full battery ready to go for the day.Oh and by the way, Lightning was designed to be plugged in every night, so it doesn't wear out.As a HUGE plus, I don't need a "base station" at all, and if I want to plug the phone in somewhere else, I only need to take the wall charger, which is so small and light it practically disappears in my pocket.

author: zapta
author_rank: Super Contributor
timestamp: June 23, 2015, 02:33:15 pm
content: Quote from: Sigmoid on June 23, 2015, 02:21:38 pmThe promise of wirefree charging surfaces is that they will be universal and ubiquitous. That is, charge any device and available everywhere, homes, cars, offices, coffee shops, hotels, airports, etc, often embedded in furniture and large enough to power multiple devices. If and when this will happen, and this is a big if, you will not need to carry anything.

author: con-f-use
author_rank: Unknown
timestamp: June 23, 2015, 02:50:38 pm
content: I use wireless charging as well. With a bit of woodworking I carved out the underside of my night table and put the gutted electronics of the charging base in there. Result: I can put my phone on the night stand, it charges effortlessly and nobody notices anything of the charger. I like it an will never have to repair another usb port on my phone. The things break loose some times, especially for old phones. Sofor wireless charging!

author: Fred27
author_rank: Unknown
timestamp: June 23, 2015, 03:01:26 pm
content: After using wireless charging I must admit I found it better than I thought I would. Great on my Nexus 5 and Moto 360. Sure, it's not a great effort to plug in a cable but I have become a bit of a fan. I even shoehorned Qi charging pads into a couple of Nook eReaders and they have weeks of battery life so they didn't really need it.I recently bought a lamp with integrated charging from Ikea. Whilst the idea is good that's the only thing I've had problems with. Might just be a dodgy one but charging seems flaky.

author: suicidaleggroll
author_rank: Super Contributor
timestamp: June 23, 2015, 03:26:06 pm
content: Quote from: zapta on June 23, 2015, 02:33:15 pmThe problem with wireless charging is that you can't use the device while it's charging. So what good is having a charger in your car or coffee shop or airport, when you have to set it there and then sit next to it, not using it, for the next hour in order for it to do anything? Why not just take a second to plug it in, and then you can actually use it during that hour?I understand the draw of wireless charging for people who's devices use microUSB, it's a terrible standard. Cables that wear out, jacks that break off, non-reversible, and a PITA to see the proper orientation. I absolutely get the draw of just setting it down and not worrying about all of that crap. Once USB-C comes out, pretty much all of that will disappear, and I wouldn't be surprised if wireless charging disappeared along with it.

author: Sigmoid
author_rank: Frequent Contributor
timestamp: June 23, 2015, 05:09:12 pm
content: Quote from: suicidaleggroll on June 23, 2015, 03:26:06 pmLol. I do understand it, but it sounds a bit silly... It's as if people popularized flight because they found the seats in the Ford Model T uncomfortable. What the mobile world needs is a good plug standard, not wireless charging. I have no idea about USB-C yet, the original concepts I've seen, that looked like Lightning, were pretty cool (I use Lightning and it's the most functional plug design ever), however I have worries about the thin "tongue" that USB-C sockets have in the final version - all in all it seems almost identically flimsy to MicroUSB, apart from the reversibility.The ultimate test of a connector is the "drunken brute" test. If a brute of a man, completely drunk, in the dark, can reliably fumble the cable into the socket without causing damage to either or both, then it's a good connector. Lightning passes. Most USB plugs fail spectacularly. Fumble around with Micro-USB, and you'll probably destroy both the device AND the cable.Quote from: zapta on June 23, 2015, 02:33:15 pmWell that has nothing to do with the actual merits of the technology. Actually, they could equally have power outlets everywhere you go... Hey, the cooler places around actually DO!Also, I definitely do not want the bar table I lean over to emit enough power to charge a cellphone... OR the desk at work... OR the table at Starbucks. OR, really, anything I might regularly and closely interact with.

author: nctnico
author_rank: Super Contributor
timestamp: June 23, 2015, 05:39:10 pm
content: Quote from: Sigmoid on June 23, 2015, 05:09:12 pmPlease read some info on the subject before posting. A wireless charger only emits energy if a device (which is recognised) is on top of it.

author: owiecc
author_rank: Frequent Contributor
timestamp: June 23, 2015, 06:07:21 pm
content: Quote from: Sigmoid on June 23, 2015, 05:09:12 pmBe careful about the sun then. I heard it can power whole nations with its electromagnetic radiation.

author: suicidaleggroll
author_rank: Super Contributor
timestamp: June 23, 2015, 06:28:44 pm
content: Quote from: owiecc on June 23, 2015, 06:07:21 pmFunny you should mention that...the power density is actually pretty comparable.Depending on zenith angle, solar radiation is on the order of 800 W/m^2 on a bright sunny day. That means a 6"x6" square (36 in^2, ~230 cm^2) is about 18.6 W. If the wireless charger is capable of feeding 10W (2A) into the phone with ~50% efficiency, the power density is the same as being outside on a bright sunny day, and we all know what kind of damage that can do to your skin without protection.I'm not saying the two are equivalent and Qi chargers will start giving people skin cancer, I just thought it was interesting that your tongue-in-cheek comment about the sun actually has a similar power density.

author: linux-works
author_rank: Super Contributor
timestamp: June 23, 2015, 06:36:03 pm
content: now, I want to build a Qi charger and connect it to a solar cell; and watch them battle it out.

author: klr5205
author_rank: Regular Contributor
timestamp: June 23, 2015, 07:24:55 pm
content: I have adopted wireless charging, but to me it's a bandaid over the greater issue of smartphone battery life. If phones could make it through an entire day for every single use-case (with several hours of screen-on time), then I wouldn't have been interested.I tried a couple chargers and found a cheap $6 model that worked flawlessly for me so I bought a handful and scattered them throughout my life. Basically anywhere I'm going to be stationary for a period of time I can plop my phone down without a thought and always have a fully charged device.In the context of phones, of course nobody NEEDS one, but its a nice convenience. Certainly worth a couple hundred pennies to this user.

author: Galenbo
author_rank: Super Contributor
timestamp: June 23, 2015, 10:37:45 pm
content: Quote from: Jeroen3 on June 23, 2015, 09:00:15 amNot everybody spends all his time at the office.Do you really need 10 examples or was this a joke?

author: NiHaoMike
author_rank: Super Contributor
timestamp: June 24, 2015, 05:23:56 am
content: Maybe wireless charging would be more trustable in public than USB due to hacking concerns?

author: Delta
author_rank: Super Contributor
timestamp: June 24, 2015, 08:28:02 am
content: A nearly completely pointless technology. Primarily done for image and marketing purposes. I'm happy to slave away for one second and plug a cable in...

author: Fred27
author_rank: Unknown
timestamp: June 24, 2015, 09:12:51 am
content: Easy to spot the iPhone users in this thread. Don't worry. Wireless charging will suddenly become great when Apple invent it for the iPhone 8.

author: con-f-use
author_rank: Unknown
timestamp: June 24, 2015, 09:14:13 am
content: Quote from: suicidaleggroll on June 23, 2015, 03:26:06 pmYou shouldn't be handling your phone while driving anyway. You can still use a headset or hands-free kit in those situations, and usually you would charge the phone at knight while sleeping. If your phone doesn't have enough battery life to get you through the day, then it's a poor one.

author: Jeroen3
author_rank: Super Contributor
timestamp: June 24, 2015, 09:43:54 am
content: Yes, iCharge will be revolutionary and exclusively for iPhones.The new Samsung flagship phone has it build in right? It's not very far away.It was actually supposed to be in the galaxy already, but it posed more complicated than expected.

author: con-f-use
author_rank: Unknown
timestamp: June 24, 2015, 10:58:23 am
content: Quote from: mojo-chan on June 20, 2015, 05:29:48 pmCould you point me in the direction of this magic device?Never mind, it's the QE-TM101-K and it seems to be damn expensive outside of Japan. I wonder how they move the coil and detect where the phone is. The other more wasteful approach is to have a lot of coils and use the one that's aligned best.

author: dexters_lab
author_rank: Unknown
timestamp: June 24, 2015, 11:59:08 am
content: Quote from: con-f-use on June 24, 2015, 10:58:23 amreading this thread made me think of the TM101 so i just bought one, i meant to get one for my panasonic usb power banks when i was in japan last year but just forgot about it.When it arrives i will pop it open and see how the alignment works.

author: zapta
author_rank: Super Contributor
timestamp: June 24, 2015, 12:43:52 pm
content: Quote from: Fred27 on June 24, 2015, 09:12:51 amBut then it will be the right time for this technology.

author: Sigmoid
author_rank: Frequent Contributor
timestamp: June 24, 2015, 03:17:11 pm
content: Quote from: nctnico on June 23, 2015, 05:39:10 pmOkay, but if there are a dozen guys charging phones, it's still an awful lot of additional EM.Quote from: owiecc on June 23, 2015, 06:07:21 pmLol. No, I'm not wearing tinfoil hats, nor am I buying a shack in the middle of nowhere to get away from all t3h 3v1l EM. But we already have a LOT of emission around us, most of it relatively low power, and for stuff that's genuinely useful (like WIFI).I'm extremely skeptical about adding even more emission, high power to boot, just so you can spare the arduous labor of the two seconds spent plugging a plug into a socket.Quote from: Fred27 on June 24, 2015, 09:12:51 amApple has a plug that works.

author: nctnico
author_rank: Super Contributor
timestamp: June 24, 2015, 08:40:30 pm
content: Quote from: Sigmoid on June 24, 2015, 03:17:11 pmNot really. A magnetic field is like water and electricity: it will follow the path of least resistance which in case of wireless charging is through the ferrite tiles of the coils.

author: Postal666
author_rank: Regular Contributor
timestamp: June 24, 2015, 09:21:55 pm
content: Quote from: fubar.gr on June 20, 2015, 05:06:49 pmLazy?Try having kids. I have 4 and they all have tablets; the youngest two can't seem to grasp the concept of "gentle" and as such I've replaced/repaired the usb jacks twice on one, once on the other. This last time I said screw it and just took the usb connector out completely. They don't do file transfers anyway so who cares. My point? I bought the cheapest Chinese QI pad I could find on ebay, and it works. You think a 7 year old cares about the drawbacks of wireless charging? Nope. All he knows is that if he puts it on the charging pad and waits for the blue sync led to come on he'll have a charged tablet when he wakes up in the morning. No, it will never be as efficient or quick as plugging in, or be a replacement for such, but it does "work" and this one example makes it less of a gimmick, and your comment a tad more dickheadish.

author: linux-works
author_rank: Super Contributor
timestamp: June 25, 2015, 03:05:05 pm
content: looks like an antenna on RAILS!motorized 'charge seeking' (or really, load seeking)??