How does wireless smartphone charging work? August 21st, 2016
Now more and more often I hear about wireless charging. Four months ago, when I was looking for a new car, I saw a Kia "Sportage" with such a built-in charger. I also thought, who is it designed for, for units? It seemed that for this you need to have some kind of cool phone model or some kind of expensive equipment. But it turns out that my mid-range phone also supports this technology. I thought, I do not know the principles of how it works. It seemed to me that this technology is still quite "far" from the layman, but it is already nearby and quite accessible.
Let's take a closer look...
It turns out that the principle of operation of a wireless charger is very simple - just place the gadget on a special panel to charge it. The accessory is based on the principle of operation of the induction coil.
Cordless toothbrushes have been using wireless charging for a long time. The technology has traditionally been accompanied by problems of low efficiency and slow charging, but these were not a critical drawback for a toothbrush or electric razor that you only use for a few minutes every day. Using inductive charging is safer in that there is no wire and it won't short out and you won't accidentally touch badly insulated areas with wet hands.
This method of energy transfer has become very popular in recent times. In 2015, the globally popular brand began selling furniture that will have a built-in wireless charging module. Today, all flagship smartphones support Qi.
It is expected that soon transmitters or, in other words, modules can be found at airports, restaurants, cinemas, fast food, shopping centers, which will allow charging phones and tablets at any time. In fact, this will make life easier for users of mobile gadgets. We are entering a new era where it is not necessary to carry wired chargers everywhere with us for all the devices we use.
The wireless power standard is called Qi. In Russian transcription, the word is pronounced as "Qi". The standard bears such a name in honor of the term of Eastern philosophy and means the flow of energy. It is developed by the WPC Wireless Electromagnetic Energy Consortium. This organization brings together world electronics manufacturers and sets itself an important task - to standardize the process of charging gadgets using the induction method. In the near future, all devices can be charged without being connected to the network. It's incredibly convenient. Each of us at least once faced with a situation where the smartphone is discharged. We urgently need to find a way out. Soon, wireless charging modules will appear in all public places, as well as at every user's home.
At home, you can simply place the module in a convenient place, and it will never get lost, unlike wired "charging". It is enough just to place a gadget on it, wait a bit until the battery capacity is replenished. The principle of operation of wireless "charging" is based on the properties of an induction coil to transmit electric current. In the school physics course, we were taught that when an induction coil is connected to a power source, a magnetic field arises in it perpendicular to the turns of the coil. Thus, if you place two coils within the range of the magnetic field and at the same time connect one of them to a power source, then voltage will appear in the second coil. In this case, it is important to take into account the fact that two induction coils should in no case be in contact with each other. Such a simple principle lies in the operation of wireless chargers that support Qi technology.
There are two varieties of the Qi standard. The first involves charging at low power - 5 watts, and the second - at high power - 120 watts. Qi high power is not currently produced by manufacturers due to objective factors. With Qi at 120 watts, you can charge your laptop. Qi at 5 watts is used to replenish the battery capacity of tablet computers and phones. It should be noted that different current strengths are required for a tablet and a smartphone. A wireless charger for a phone creates a current of 1 amp, and for a tablet computer - 2 amps. When choosing an accessory, be sure to pay attention to such characteristics.
A modern wireless charger consists of two components. One of them is built directly into a gadget that supports Qi and is called a wireless charging receiver. In fact, it is a receiver that conducts electrical current to the battery. The second component is called the transmitter. If the purchase of wireless “charging” is meant, we are talking about the transmitter. They come in a variety of shapes and sizes. The most common are round and rectangular transmitters.
To better understand how wireless charging works, it should be noted that the magnetic field is capable of transmitting not only electric current, but also data on bytes and bits, which was taken into account by the developers of the Qi standard. The interaction between the coils will only occur when the gadget with the built-in transmitter is close to the transmitter. If the accessory for charging the gadget will function in the background, then the pulse sent every 0.4 seconds by the transmitter will not change the voltage in the coil built into the transmitter. We can conclude that a modern accessory can recognize in which mode to function. As soon as a smartphone is nearby at a distance of several centimeters, the voltage in the induction coil will drop sharply, and the device will switch to active mode. As soon as the smartphone's battery is charged, the corresponding signal will put the charger into the background. It can be concluded that modern wireless accessories for battery replenishment are energy efficient.
More charts and formulas
Some users mistakenly believe that the Qi wireless charging function can be harmful to health. The fact is that magnetic radiation is not ionizing. In its effect on the body, it is similar to a mobile signal, a Wi-Fi signal, a radio signal. At the same time, the signal of the mobile network that comes from the tower is stronger and has a continuous character, while electromagnetic radiation disappears immediately after charging the smartphone battery. The power of wireless chargers is 5 watts. It is not enough to have an effect on the human body. We can talk about a negative impact only if the power of such devices is 120 watts. But such models are not produced on an industrial scale. This explains the lack of wireless chargers for laptops. It is important to know that wireless battery charging technology has long been used in many models of electric shavers and electric toothbrushes, which once again proves its safety.
prospects
This inductive charging may be convenient, but the short range is a problem. This drastically reduces the usability of this technology. Will this change? May be. There has been a lot of research into the potential of wireless charging and there have been advances in range in various technologies. Lasers, microwave ovens, and more powerful variants of inductive charging have been able to achieve longer transmission distances. Disadvantages prevent widespread this too powerful radiation of the above technologies. You can get burned or worse. It is difficult to say who will take the lead in this market. The first candidate is Apple, because the company has patented a device that can allegedly charge at a distance of up to one meter. The Wireless Power Consortium is also constantly looking for better options. And then there's Intel, which recently announced that it's working on an integrated magnetic device technology that will be placed in a laptop and distribute power to nearby smartphones and peripherals.
sources
A technology has now become available that allows you to charge phones without using a cable. Its advantage is that this procedure is faster and easier, and you do not have to connect your smartphone to the network every time - just place the device on top of the wireless charging pad.
There are various competing standards for this technology. The most popular of these is Qi, which is today backed by companies such as Samsung, Google, and Nokia. However, more and more manufacturers are starting to use it in one form or another.
Which phones support wireless charging?
Some smartphone models have a built-in wireless charging function (their rating is presented below). Other devices will need to replace the back cover or case for this. Components for Qi are produced for specific phones, so if you connect them yourself, you should make sure that you select a compatible model.
If a dedicated wireless charging cover is not available for your smartphone, you can use a universal adapter that allows you to use this technology even for older devices.
What do you need to know about wireless charging?
As noted above, the current leader is the Qi standard, which is currently used in most Android devices. The technology works by using magnetic induction to allow energy to be transferred from the platform to the phone's battery. The Qi standard, whose name in Chinese means "air" or "spiritual energy flow", was created in 2008 and began to be developed simultaneously with the participation of 206 companies, including Microsoft, Samsung and Sony.
Speaking about which devices support wireless charging, we should also remember about the less common PMA standard. It also works due to magnetic induction, but its distribution area is somewhat lower. In June 2014, the developers of the PMA standard partnered with Duracell to place charging platforms in some public places in the US to promote the technology. If this idea proves viable in the future, it is possible that more smartphone manufacturers will start using this standard.
If we talk about which phone models support Qi-standard wireless charging, then the choice will be very large. Even if your Android smartphone doesn't have this technology built in, you can get a universal Qi receiver that only costs about $15. Despite the bulkiness, it will add significant convenience to you when using the gadget. The device attaches to the back of your device, which can then be placed on any Qi-compatible charging platform. Regarding the question of which phones support Qi wireless charging, it is worth noting that there is a receiver for the iPhone (5, 5s and 6 models) on sale, which also receives positive reviews. Its cost is about 30 dollars.
Which phones support wireless charging (list of gadgets)
Those who are interested in the new technology will find it useful to know the rating of devices that have built-in Qi standards.
The best known model in this regard is the one which is currently available for around $200. According to user reviews, this is one of the best Android devices in general. Also, this device is a leader in the use of wireless charging. The smartphone is compatible with both Qi and PMA technologies. With its elegant design, good performance and large 16-megapixel camera, this phone outperforms the iPhone in some ways. Commercially available Qi memory has a good long cable for connecting to the network. Its edges are illuminated with a light blue tint during charging and turn green when it is completed.
Among the devices that can charge wirelessly are the following:
- Samsung Galaxy Note Edge.
- Samsung Galaxy Note 4.
- Google Nexus 6.
- Motorola Droid Turbo and others.
Other Samsung models
Analyzing which Samsung phones support wireless charging, one cannot help but remember about this model. This model also simultaneously supports both standards - both Qi and PMA. The attractive curved shape of the case and the convenient screen allow owners to instantly access messages and other important data, and the built-in adapter does not impair the use of the device in any way. If the gadget itself can be purchased for about $300, the cost of the Pad to charge would be about $40.
Also belongs to this category of devices. This smartphone with an innovative curved screen offers very strong graphics performance on a bright display. Its screen size is much larger than other devices, so battery consumption is correspondingly faster. In this model, the wireless charging capability is not integrated directly into the back of the phone, but a special Samsung Qi-enabled cover is available for sale that replaces the standard back of the device. This component costs approximately $25 and is available in two colors: jet black and snow white.
If you ask which phones support wireless charging in general, you will notice that this technology mainly affects gadgets with high hardware capacities, for which the ability to quickly charge them is especially important.
Based on this, it is not surprising that it is also equipped with the described technology. This gadget is characterized by high multitasking, fast and high-quality camera and high brightness of the screen, which has a size of 5.7 inches. In order to carry out its wireless charging, you will need a special case. It's available for around $30 and comes in two colorways.
However, Samsung is not the only manufacturer to massively use this technology. Which phones from other brands support wireless charging? Consider below.
Other brands
Google Nexus 6 has a nearly 6-inch screen and is equipped with a high-powered processor, so it especially needs the ability to quickly and quickly recharge. Qi technology is built in from the start, so there is no need to buy an additional cover or case. This gadget is quite expensive - about $ 500, but fans highly appreciate its hardware power along with Android 5.0. All this offers users a high level of comfort. Although there is no dedicated wireless charging platform, a universal accessory will do the job just fine.
Speaking about which phones support wireless charging, one cannot but touch upon a model such as the Motorola Droid Turbo. This smartphone with a screen of just over 5 inches has a camera with a resolution of 21 megapixels and many built-in features. Its battery life is approximately 9 hours under active use, so the built-in Qi technology is very useful. There is also a special charger for this model, which places the phone in a vertical position. This means that while charging, you can continue to use the device.
Sony brand
As already noted, the most actively new technology is used by manufacturers such as Samsung, Google and Sony. Which Sony phones support wireless charging? First of all, this is the Sony Xperia Z3 - a waterproof gadget that, with active use, works up to 12 hours without recharging. Its screen is high brightness, and the speakers provide loud chic acoustics. Despite the fact that its cost is about $ 400, the device is very popular. The wireless charging cover will have to be purchased separately and costs over $100.
Can you adapt your smartphone?
What phones support wireless charging without built-in technology? If your device does not natively support Qi, you can separately purchase and install an adapter on it and use the universal wireless charger. Depending on the brand of the gadget, you can connect the adapter via the micro-USB port (on the Android platform) or lightning (on the iPhone).
Universal wireless charging adapters
If your phone is not listed above, then you need a universal adapter and wireless charger. You can get them for phones with micro USB ports (like Android) and lightning ports (like iPhone). Thus, you can update and improve almost all devices available for sale. If we talk about, for example, which Xiaomi phones support wireless charging, then with the above method you will be able to charge even 5-year-old models without a cable.
Universal charger
Once you've made sure your phone supports wireless charging (by built-in functionality, using a special cover, or by connecting an adapter - it doesn't matter), you need to purchase a wireless charger.
Currently, there are many such Qi devices available in various sizes, shapes and colors. You can buy such a component not only for use at home or in the office, but also for a car, and even a Qi portable battery. If you have purchased a smartphone that supports wireless charging, it is advisable to choose a charger specially designed for it. If there is none, or you have updated your gadget yourself, finding a universal device is not difficult.
The increase in battery capacity in modern smartphones generates an increase in recharge time. To speed up the process, manufacturers are developing new technologies like QuickCharge, VOOC or PumpExpress. However, all of them are only designed to reduce the time spent on charging, but do not present anything radically new. Another development path is wireless charging. This promising direction, although slowly, is developing.
The convenience of wireless charging lies in the fact that you do not need to get tangled in wires and aim the cable plug at a small connector. The speed still leaves much to be desired, but you can recharge your smartphone by simply placing it in close proximity to a special source of electromagnetic radiation. Smartphones that support wireless charging and are relevant in 2016 will be discussed in the selection.
In February 2016, the company introduced a pair of new flagships, the Galaxy S7 and S7 Edge. Now they can be bought at a price of 550 and 600 dollars, respectively. Both smartphones feature a high level of performance, excellent cameras and support for wireless charging. They can replenish the battery capacity through Qi standard pads (more popular). The PMA wireless standard is also supported. In general, the devices are balanced and good in everything.
- Screen: Super AMOLED matrix, resolution 2560x1440 pixels, flat 5.1" (S7) or curved 5.5" (S7 Edge)
- Processor and Graphics: Samsung Exynos 8890 8-core + Mali T880 MP12 GPU, or Qualcomm Snapdragon 820 4-core + Adreno 530 GPU (market dependent)
- Memory: 4 GB RAM, 32 or 64 GB permanent + MicroSD
- Camera: resolution 12 MP, size 1/2.5", pixel size 1.4 µm, aperture f/1.7, DualPixel full phase autofocus), flash, OIS (optical stabilization), 4k video recording, front - 5 MP, f /1.7
- Battery: 3000 mAh (S7), 3600 mAh (S7 Edge)
- OS: Android 6
The combination of advanced functionality and premium design make these smartphones one of the best in 2016. Claims, by and large, they have nothing to present at all (except for a not very affordable price).
Samsung Galaxy S6 and S6 Edge are thin flagships
Despite the fact that the Samsung Galaxy S6 and S6 Edge came out last year, they remain relevant in 2016. Now you can buy devices from $400 or $500, respectively. In addition to the top-end filling at the time of the presentation (which is still not listed as an outsider), smartphones received thin cases. Both models support Qi (Qi) and PMA fast charging.
Samsung Galaxy S6 and S6 Edge are powerful and well-balanced smartphones that you can now buy for normal money. Of the minuses, we can mention the lack of a slot for a flash drive.
LG Nexus 5 - compact ex-flagship
Three years have passed since the release of LG Nexus 5, but it is difficult to call it ancient. The smartphone remains relevant in 2016, although it is no longer able to compete with the flagships. It has an excellent display and a good camera that can beat some of the newer 13MP and 16MP models. LG Nexus 5 supports Qi wireless charging. You can find a smartphone now at a price of $ 160.
The smartphone is quite capable of arguing with the mid-budget 2016 (and surpass them). Of the minuses - the lack of a slot for a flash drive and a small battery.
Motorola Nexus 6 big screen phablet with stereo sound
The large Googlephone Motorola Nexus 6 was released 2 years ago, and as of the fall of 2016, it looks like a strong middle peasant. Large screen with high resolution, laconic design - these are the main advantages of the device. The smartphone supports Qi wireless charging. The price of the phablet at the time of compilation is from $270.
- Display: AMOLED, 2560x1440, 5.96"
- Processor and Graphics: Snapdragon 805, 4 cores + Adreno 420
- Memory: 3 GB operational, 32/64 GB permanent
- Camera: 13 MP, 1/3", 1.4 µm, f/2, autofocus, flash, OIS, 4K video, front - 2 MP, f/2.2
- Battery: 3220 mAh
- OS: Android 5, upgrade to version 7
Traditionally for Nexus, Motorola Nexus 6 has the main disadvantage - the lack of MicroSD. But the advantages of Motorola Nexus 6 include stereo speakers on the front panel. 
LG G3 D855 - thin bezel phablet
Released in the summer of 2014, the LG G3 D855 is a flagship device at that time, or a mid-range device for the fall of 2016. Considering that you can buy it now for $ 180, age does not matter by mobile standards. Moreover, the device has thin frames (the screen occupies more than 75% of the front panel), and is also equipped with a dedicated DAC and a Qi wireless charging module.
- Display: IPS, 2560x1440 pixels, 5.5"
- Processor and Graphics: Snapdragon 801, 4 cores + Adreno 330
- Memory: 2 or 3 GB RAM, 16 or 32 GB permanent + MicroSD
- Camera: 13 MP, 1/3", 1.12 µm, f/2.4, phase + laser autofocus, flash, optical stabilization, 4K video, front - 2 MP, f/2
- Battery: 3000 mAh
- OS: Android 4.4 upgrade to version 6
Thanks to the large screen with high resolution, compact (as for 5.5 ") dimensions and a good battery - the smartphone is still sold and has admirers. 
Microsoft Lumia 950 - the last of the Mohicans
In 2016, fans of the Windows Phone OS were overtaken by the sad news: Microsoft stopped producing Lumia series smartphones. Microsoft's Lumia 950 was the last flagship to be released on the basis of this system at the end of 2015. The device received the top-end hardware at that time and a Qi wireless charging module. Now you can buy Microsoft Lumia 950 by paying from $350.
- Screen: AMOLED, 2560x1440, 5.2"
- Processor and Graphics: Qualcomm Snapdragon 808, 6 cores + Adreno 418
- Memory: 3 GB RAM, 32 GB storage + microSD
- Camera: 20 MP, 1/2.4", 1.12 µm, f/1.9 Carl Zeiss, autofocus, flash, OIS, 4K video recording, front - 5 MP, f/2.4
- Battery: 3000 mAh
- OS: Windows 10 (Phone)
The Microsoft Lumia 950 is one of the best Microsoft smartphones of all time. For fans of the operating system from MS, who do not want to part with it, this is the best device. 
Samsung Galaxy Note 5 is a slim phablet with a stylus
Released in the summer of 2015, the Samsung Galaxy Note 5, due to the unsuccessful release of the successor, in 2016 remains the last successful flagship in this line. The device is equipped with hardware that is still relevant today, a good camera, and also has a large front panel to display area ratio (76%). It is equipped with wireless charging that works with the Qi standard. PMA wireless charging is also supported. You can buy Samsung Galaxy Note 5 by paying from $570.
- Screen: Super AMOLED, 2560x1440 pixels, 5.7"
- Processor and Graphics: Exynos 7420, 8 cores + Mali T760 MP8
- Memory: 4 GB RAM, 32/64/128 GB ROM
- Camera: 16 MP, 1 / 2.6", 1.12 μm, f / 1.9, phase detection autofocus, flash, optical stabilization, 4K video, front - 5 MP, f / 1.9
- Battery: 3000 mAh
- OS: Android 5.1, Android 6 update
Among the advantages of the Samsung Galaxy Note 5, one can also note a dedicated DAC and a proprietary stylus, and the lack of a memory card slot can be added to the disadvantages. 
Other smartphones
Other smartphones that support wireless charging that are not included in our selection:*
- ZTE V975 Geek
- Nokia Lumia 930
- Nokia Lumia 920
- Nokia Lumia 925
- Nokia Lumia 1520
- Nokia Lumia 720
- Nokia Lumia 810
- Nokia Lumia 820
- Nokia Lumia 822
- Nokia Lumia 928
- Samsung Galaxy Note Edge
- Blackberry 9700
- Blackberry 9700
- Fujitsu F-03D
- Fujitsu F-09D
- HTC 8X
- HTC Droid DNA
- HTC Droid Incredible 2
- HTC Droid Incredible 4G
- HTC Rezound
- HTC Thunderbolt
- LG Optimus G Pro
- LG Spectrum
- LG-Google Nexus 4
- LG Lucid 2
- LG-Optimus F5
- Motorola Droid Bionic
- Motorola Droid 4
- Motorola Droid 3
- NEC N-01D
- NEC N-04E
- Panasonic P-02E
- Panasonic P-06D
- Pilips Xenium
- Sharp SH-02D
- Sharp SH-04D
- Sharp SH-04E
- Sharp SH-05D
- Sharp SH-07D
- Sharp SH-09D
- Sharp SH-13C
- Sharp SH-13C
- Sony Xperia Z
*in fact, there are more smartphones that support wireless charging, and some of the list only support separately connected overlays with an "over-the-air" charge receiver. Find out about the smartphone you are interested in in the comments to this article. You can also expand this list by writing the smartphone model in the comments.
There are special adapters that you can purchase and build yourself under the cover of your smartphone and the device will support wireless charging. They are connected via contacts for the NFC antenna. You can see how it looks in the video after the list of smartphones that support such adapters:
- Samsung Galaxy S3
- Samsung Galaxy S4
- Samsung Galaxy S5
- Samsung Galaxy Note 2
- Samsung Galaxy Note 3
- Samsung Galaxy Note 4
There are similar adapters for the iPhone, but they are connected via a connector and have a small cable so that the cover with the charge receiver can be bent and attached to the back cover. However, the practicality of such a design is questionable. 
In addition to such devices, you can find adapter cases for iPhones on the Chinese market with the ability to charge your smartphone wirelessly, but in this case you will have to sacrifice thickness.
There are options, like in the Jiayu G6 smartphone, which has an open adapter slot on the back cover. However, to use the wireless charger, you will need to purchase an original smartphone case. 
The method of charging gadgets without direct contact with wires is becoming more and more firmly established in our lives.
It is no longer necessary to regularly connect the phone with wires to the socket. It is enough to place it on a special surface, and the battery will begin to receive power.
How does wireless charging work?
At the heart of wireless chargers is such a physical phenomenon as magnetic induction, which allows you to transfer electricity over a distance from one induction coil to another.
The main part of such a device is a charging station, which is a primary coil in a plastic case. It is connected to an electrical outlet, after which an electromagnetic field is created around it at a short distance. A smartphone equipped with a secondary receiver coil is placed on the charging station and begins to receive electricity to power the battery.
What is Qi?
Theoretically, the possibility of wireless charging can be implemented in various ways, so the characteristics of the charging station may vary. This means that a wireless charger from one smartphone may not work with a smartphone from another manufacturer.
To avoid this, global electronics manufacturers have united in the Wireless Electromagnetic Energy Consortium and adopted a single standard called Qi. In Russian, this is read as "Qi". It is within this standard that most wireless chargers and phones are manufactured.
The maximum power of wireless chargers is 5W with a current of 1A. This is enough to successfully charge the smartphone battery. The efficiency of such charges is somewhat lower than those that work from sockets, so it will take a little more time to reach 100% charge.
On top smartphones of well-known brands, such as Samsung and iPhone, the receiver (receiving coil) is installed at the production stage, and this does not affect the thickness of the gadgets - they remain thin.
DIY wireless charging
If the manufacturer did not provide for the possibility of wireless charging initially, then with the help of a special adapter you can fill this gap. There are special films with an induction coil on sale, which are selected depending on the smartphone model. They can be installed under its cover. In this case, the connection is made via the contacts provided for this purpose.
It is also possible to place the coil between the back cover and the case, and a special cable from it is installed in the power connector. The thickness of such a receiver film is about 2 mm, so the external gadget will hardly change.
In terms of intensity, electromagnetic radiation from the charging station is lower when compared with a cellular signal. Upon reaching 100% battery charge, the power controller turns off the induction field. Therefore, users should not be afraid for their health - such a charger will not cause any harm.
Where to charge "by air"?
The wireless method of charging the battery is gaining more and more recognition. In cinemas, cafes, airports, special podiums for wireless charging appear. Thanks to a single standard, they can charge any phones that support Qi.
Manufacturers of interior elements successfully install charging stations in tables, armchairs, table lamps. In new car models, engineers have provided special podiums in the dashboard, on which you can place a smartphone for charging. Moreover, now there is no need to purchase cigarette lighter chargers for the car, which saves the user from unnecessary wires.
If you are hearing about wireless charging technology for the first time, we strongly recommend reading this material.
With the world on a string
So, at MWC 2013 (Mobile World Congress, if what), the presentation of wireless chargers looked somewhat generalized compared to the previous year. And it looks like we've all seen it before.
Recall that in 2012, Duracell devoted a separate stand to wireless chargers, showing whole sets of devices at a price of no more than $130 (US price). Among the new products, the company also introduced the Wireless Charging Card, a special insert that could be placed under the cover of almost every mobile device without harming the strength of the case. With a thickness of less than 1 mm, the liner does not lead to the formation of backlashes or a loose connection of the cover to the body of the smartphone. The Wireless Charging Card today has many analogues, and this development was not the first of its kind.
In addition to Duracell, the Wireless Power Consortium Association also prepared a wireless charging stand, which, by the way, came up with the idea of standardizing wireless charging technology (later called Qi, read as "qi"). The WPC includes dozens of the largest companies from around the world. Offhand, among others appear Energizer, Samsung, LG, Philips, Nokia, Sony and, more recently, the same Duracell. In addition to Qi, the Association has earned another fat plus in karma by making all products certified by it compatible. Those. Qi-charger from Nokia can charge not only its own smartphones of this brand, but also any other gadget that meets the generally accepted standard. And if suddenly you carry a smartphone with an insert from Duracell in your pocket, you can also charge your mobile on any of the bases that support Qi.
There was only one booth this year. Technologically, developments have not gone far, but a couple of innovations nevertheless appeared: firstly, in 2012, it was possible to charge mobile communication devices using Qi, and only because The maximum power of 5 watts was enough for this. The prototype 35-watt charger, also presented at the World Congress, did not look very confident, so the consultants immediately hinted that the device was still under development. At the current MWC, devices with a power of up to 120 watts have already been presented, which is enough to charge tablets.
The inductive charging principle has not yet allowed manufacturers to change the shape of the distributing and receiving parts of the device. Wireless charging, in fact, is two coils - distributing and receiving - between which a magnetic field arises. Often we do not see the unpretentious internal structure of the charger, but some manufacturers have managed to beat it. So, the ring-shaped PowerKiss adapters caused special joy, thanks to which even phones without a built-in Qi module can be recharged.
PowerKiss, due to the release of several versions of the USB connector, you can connect to absolutely any phone or smartphone, lay the gadget flat on the station and enjoy wireless charging. They are released in different colors, which can also be added to the treasury of the useful characteristics of the device.
At MWC 2013, the PowerKiss was shown again, and with them some very reasonable solutions for adapting the transmitter. It is proposed to make it not in the form of a stand-alone object, but, for example, to discreetly adapt it to a specific interior: instead of the usual mat or stand, the base can be located in the handle of your sofa, located in the cover of a multimedia center or speakers.
The latter option has already been embodied in TDK products: Wireless Charging Speaker Q35 looks stylish, and, in addition to its intended purpose, it also charges your cell phones.
Issue price
Unfortunately, none of the listed devices fell into our hands, so we will limit ourselves only to general specifications and, in fact, price tags.
Devices that support wireless charging technology can be divided into two categories. Those in which this possibility is incorporated by the manufacturer are called “Qi Integrated”. Phones out of the box that accept Qi will be slightly larger than the rest. But you do not have to glue inserts under the cover or connect any other spare parts built into the case. It will be necessary to buy a distributing base and that, in fact, is all.
The “Qi Ready” category includes devices that are predisposed to Qi, but require a technological upgrade to ensure the full operation of the technology. The shopping list in this case will include both the transmitter and the receiver.
True, you will most likely not find either the first or the second designation on the box of the device. Manufacturers are often simply limited to mentioning the possibility of connecting a smartphone or tablet to Qi. What kind of phone you got, you can find out only by opening the package. Or, say, from detailed reviews of this model.
See the table of Qi-enabled phones below. Listed here are compatible models released as of early 2013.
On sale, as you might have guessed, you can find both a Qi-charging kit and a base and a receiver separately. For example, the Philips DLP7210B kit is a cover for the rear panel of the device with an energy receiver coil, as well as a charge transfer base. The Qi-charging kit for the Samsung Galaxy S4 was made on a similar principle.
Production subtleties
With Qi, the market for chargers has expanded significantly. Judge for yourself: if earlier we were somehow not very picky about the performance of adapters, now we have the right to turn our noses a little. The consumer chooses the device according to the shape, color and principle of attachment to the phone. At the same time, not limited to the offers of only one brand that released a gadget owned by the consumer.
Perhaps the easiest option is to place a receiver chip under the device case if your smartphone or tablet did not initially receive one. This, firstly, will not affect the external state of the phone: it will still be hidden under the cover! And secondly, it will not significantly affect the weight of the gadget.
The cost of the receiver plate is low: for example, a universal plate for all Samsung smartphones can be bought from $11 starting. A complete set (base and receiver) will cost about $62.
Another “invisible” option for connecting your phone to Qi is a replaceable back cover with a built-in receiver. Such, as we have already said, are also in the catalogs of Nokia, Philips and Samsung.
The advantage of the back cover with a Qi-receiver is that, even though it somewhat thickens the body of the device, it also serves to protect the gadget. Such lotions do not have armor-piercing properties, but, in theory, the phone will be more whole.
A branded cover for Nokia Lumia phones will cost about $27. Note that the manufacturer produces them in several colors.
Another form of receiver is the USB-connected PowerKiss. It costs about $ 34 / piece. (according to the USA). This project is interesting because it is focused, rather, not on individual, but on mass use: furniture with built-in Qi bases, as well as PowerKiss rings scattered on the surface, may soon appear in airports, waiting rooms at train stations, in cafes, libraries and other public places where such an innovation will deservedly receive national appreciation.
PowerKiss, by the way, solves the problem of connecting smartphones to Qi bases, which, in the presence of a non-removable back cover, did not receive the corresponding wireless charging module during production. Removable panels with a Qi module can still be attached to such smartphones. But when buying a kit, you need to carefully read the specifications of the device: not all receivers are able to efficiently transfer energy through the cover. And PowerKiss provides direct communication with the battery of the device, respectively, there will be a chance to charge the battery faster with just such a “ring”.
Speaking of efficiency. Most wireless chargers are less than 80% efficient. This does not mean that your phone will not receive something, it is just that the technology is not yet perfect and you need to carefully follow the instructions in the instruction manual in order to increase the level of Qi performance in each case.
Rarely, but sometimes especially honest manufacturers admit that their device will not be able to work to the maximum, no matter how hard you try. So, for example, in the description of METRANS Wireless Transmitting Terminal MWT02 it is clearly stated: the maximum operating efficiency is 73%. At a price of almost $78, this is quite a frank warning.
If Qi, as seen in the PowerKiss example, is only planned to be integrated into the interior, especially enterprising owners of wireless chargers manage to place charging bases under the covers of bedside tables or coffee tables on their own. The following video clearly shows how easily the latest technology lends itself to such creative experiments.
Now a little about the forms of the distributing bases.
The most common option is a pad-shaped base, i.e. stands.
Recall that for the wireless charging of the gadget, it must be closely adjacent to the base. The maximum distance that a device can be lifted today for continuous power transmission is only 4 cm!
Below you can see a test of Nokia's Qi system a la "charging with obstacles."
The horizontal position of the smartphone, on the one hand, is as convenient as possible for a typical scenario: he came, threw the phone on the table. On the other hand, using a smartphone while charging is much more convenient when the same platform has a certain angle of elevation: insufficient for the smartphone to slide off, but making it easier to work with the device if it suddenly becomes necessary.
Strictly horizontal bases can be found in the directories:
- Zens (charging for one smartphone costs $65);
- Energizer (the Dual Inductive Charger base allows you to charge up to three devices: two via Qi, and the third via a standard USB port; the body of the model is slightly inclined, which is much better than the flat version for an office charging option; this costs $89);
- Duracell (the silver Powermat pad costs $34 and is designed to charge one smartphone, has a nice square shape with rounded edges);
- Nokia (DT-900 base is no larger than a computer mouse; not only for Nokia phones; price $47).
Another “flat”, but non-standard option is presented by TDK: Q35 Qi Wireless Charging Speaker costs $199 and is a speaker placed in a modern cubic case, on the top of which, in fact, the distribution coil is mounted.
