Nowadays, a person without a smartphone is a person cut off from life. It's hard to imagine that a few years ago a mobile phone was used only for communication. Now this little assistant gives us both access to the Internet and many applications, and wakes us up in the morning. The list of benefits provided by a smartphone can be continued endlessly. It is not surprising that a large number of gadgets have been invented for modern phones. One of them is a wireless charger, which we would like to talk about in more detail.
How can I tell if my phone supports wireless charging?
What is wireless charging
From the name it is clear that this is a gadget that allows you to charge your smartphone without using wires. It is a small stand connected to the network. There is an induction coil inside, which creates a small magnetic field around itself. If there is a smartphone within the radius of this field, it will receive electricity literally through the air. But there is one caveat - the smartphone must also have a built-in induction coil. It will serve as a kind of energy receiver from the charger.
The purpose of creating this device was to rid modern smartphones of charger connectors, and also to allow all devices in the house to be charged from one platform. The idea was a success, but why then don’t we see this technology in every home and don’t use it ourselves? The answer is simple - despite all the advantages, this miracle device also has disadvantages.
Doogee S60
The Doogee S60 can boast neither an attractive price tag nor an outstanding appearance. But this is one of the best secure devices in our selection. The device has a 5.2-inch display and a sealed metal case with rubber inserts, which provides it with reliable protection from mechanical damage.
The smartphone is powered by a powerful, energy-efficient eight-core Helio P25 chip from MediaTek, which easily handles the most demanding games, and 6 GB of RAM allows unlimited multitasking.
The storage capacity is 64 GB, and if necessary, the memory can be expanded using microSD cards. The main camera has a resolution of 21 megapixels, and the front one is 8 megapixels. The battery capacity is 5580 mAh.
Find out the cost on Aliexpress
Pros and cons of a wireless charger
Wireless charging has a lot of advantages, but they all have their own cornerstone.
No wires
Without a doubt, this is a big plus. Wires have always been a weak point in chargers. With frequent kinks, the wire was easily damaged and tangled. Frequent recharging loosened the USB port on the phone, and sooner or later it needed repairs. But there is also another side to the coin. Refusal of wires reduced efficiency (efficiency) from 90% to 60–75%. Simply put, when using wireless charging, your smartphone will charge approximately 2-3 times longer.
Range of use
It would seem that there are no wires - there are no restrictions, and you can charge your phone simply while in the apartment. But no - the radius of use of the wireless charger is very modest (3–5 cm) and the phone will have to be placed on a stand. Another significant drawback is the inability to use the smartphone while charging.
Price
The cost of a charger is quite variable, but it will always be more expensive than the usual charger.
Compare the best models!
To make it easier for you to choose the right wireless charging model, we recommend that you familiarize yourself with the comparative table, which shows the main technical characteristics of the most popular models.
| Model name | Price, rubles | Power, W) | Interface |
| DEXP Q5 | 300 | 5 | QI |
| Qcyber Mobile QI QM-05-001 DV01 | 380 | 5 | QI |
| Red Line YT000013569 | 700 | 6 | QI |
| Spigen Essential F301W 10W | 1 100 | 5 | QI, Quick Charge |
| DEXP ICY-W001 | 1 200 | 10 | QI, USB Type-C |
| Nillkin Magnetic Wireless Charger Car II | 1 300 | 5 | QI |
| HOCO CW10 Elegant | 1 500 | 10 | QI |
| Samsung EP-NG 930BWRGRU | 2 000 | 12 | USB Type-C, QI |
| Deppa QI Fast Carger | 2 300 | 10 | QI, USB, Quick Charge |
| Belkin BoostUp Wireless Charging Pad | 2 500 | 7.5 | QI, Quick Charge |
| Mophie Wireless Charging Base | 2 800 | 18 | QI, USB |
| Mi Wireless Charger | 3 000 | 5 | USB Type-C, QI |
| Samsung EP-PG950B Convertible | 3 700 | 5 | QI, Quick Charge |
| Samsung EP-N5100BBRGRU | 4 900 | 9 | QI, Quick Charge |
| Belkin QI F7U027vfWHT | 6 100 | 7.5 | QI, USB Type-C |
Standards
I would like to talk about the standards that made the use of technology for transmitting electricity through the air possible.
Qi standard
Qi (“Qi”, after a term in Eastern philosophy) was developed by the WPC (Wireless Power Consortium). It is the most widespread and is supported by such giants of the mobile industry as Asus, Motorola, HTC, Huawei, LG, Nokia, Samsung, Blackberry, Sony and others. You can find out more about the standard and the list of supported devices on their official website.
PMA standard
The PMA standard also uses the principle of electromagnetic induction, but does not boast as large a list of manufacturers supporting their technology as Qi. It was developed by Powermat, which is currently trying to fight unhealthy competition from Qi.
A4WP standard
This standard uses Rezence technology, which is fundamentally different from PMA and Qi. The strange thing is that the most unpopular standard has many advantages in comparison with its competitors. The advantages include:
- the ability to charge through interference (if you put a book between the smartphone and the charger, nothing will change);
- one platform can provide energy to several devices;
- work in close proximity to metal objects, etc.
Paranoia
Do cordless coils cause cancer, impotence, dementia? No more than any wiring in your home. Wireless charging is just two coils of live wire.
Is it possible to read phone data via wireless charging? No, but you can - via NFC wireless technology, if your phone is ready to share this data.
Is it possible to demagnetize a bank card using wireless charging? If the card has a magnetic stripe and you place it between the charging station and the phone for a long time, the magnetic stripe may be damaged. Card with a chip - no.
Can I cook or heat food on a wireless charger? You can if your food is coiled copper wire, and the charging station will have a power 100-200 times higher than modern ones. The wire will heat up and you can eat it. (This is a joke, don't eat the copper wire).
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Which phones support wireless charging?
You can view the full list of smartphones that can use wireless charging right out of the box on the official website https://www.wirelesspowerconsortium.com. I would like to note that most manufacturers have made sure that their product supports the use of this technology.
What if your smartphone is not on the list of supported devices, but you need to use wireless charging? If you have this question, then most likely you are a happy user of Apple products. The iPhone does not yet have the ability to receive electromagnetic signals. However, there is an alternative - purchasing an auxiliary accessory that will do this for your phone. It fits under a standard case and does not cause any discomfort.
GSM Arena
Go to the list of phones with wireless charging.
Pros:
+ displays even those smartphones that are still in development; + notes the relevance of the model (outdated, on sale or in development).
Minuses:
– a modest base on Chinese (not international) devices; – there may be errors in the characteristics.
A popular information portal in the West about mobile gadgets and technologies, it collects the most detailed material on existing and even upcoming smartphones. The developers have proposed a search tool for phones that support “wireless charging” in the characteristics criteria.
Let's sort it out
Opening the receiver went without any problems. Everything is held together by glue, but if you are not diligent, nothing will come off. Inside there is an inductor and a receiver board. The board is universal, suitable for both flipping USB 180 degrees and connecting Apple devices. The controller on the board is designated BQ51020, which can output 4-10V at a current of no more than 1.0A. The receiver board is connected to the micro USB connector with just two wires. This means that for versatility, the DATA pins are shorted to the connector itself.
Opening the transmitter. Inside is a fairly large board, a bunch of chips and loose stuff. I didn’t set out to study it, but at least I’ll post a photo.
Tests with bias
I decided to check everything that was interesting to me. - maximum transmitted current - efficiency - output energy at different receiver distances - different receiver antennas - compare two transmitters
They took part in the test.
transmitters: - Nillkin Qi charger (from the first part of the review) - LG Nexus Qi charger (lying nearby)
receivers: - Nillkin Qi charger adapter
Receiver antennas: - original - antenna-sticker from the cover from the first part of the review
First of all, I tested a set of receiver and transmitter from Nillkin. The test checked efficiency, maximum voltage, and the level of energy transfer when offset relative to the transmitter. The results are presented in a table.
The table contains data on the coordinates of the receiver, the powers of the receiver and transmitter, and efficiency. And all this while consuming 0.5A and 1.0A.
I tried to show how consumption depends on the placement of the receiver on a graph. (data for Nillkin transmitter + Nillkin receiver when receiving 1A output)
Well what can I say? Everything seems to be working. From 20 to 50% of the energy supplied to the transmitter is lost during conversion. The output can be up to 4.92V. And you definitely can’t get higher than 1A. The receiver does not heat up much during tests, but is warm within a couple of seconds after the start of generation.
Now I’ll compare both base transmitters. I did not create a detailed table of results, I simply found the points with the maximum “return” and displayed them in the table as a comparison.
It turns out that with Nillkin the receiver produces a slightly higher voltage (at the error level), but the LG has a slightly higher efficiency. In general, both bases are identical and differ only in nuances. Nillkin slowly, with a period of five seconds, tries to repeat the generation of energy. LG is more aggressive in this regard, the periods between attempts are reduced to a second.
Tests with a foil antenna (included with the cover) showed the following. This antenna is less sensitive to movements relative to the transmitter, but the transmission is interrupted instantly as soon as the invisible line is crossed. It seems preferable to Nillkin's, but apparently is not compatible with the receiver. Energy generation did not always occur, so I put it aside.
The secret is electromagnetic induction
How can energy be transferred from one object to another? Wireless charging works on the principle of electromagnetic induction . This phenomenon was first described in 1831 by Michael Faraday , who discovered that if a source of magnetic field is moved through a coil, an electric current will appear in it.
Michael Faraday discovered the relationship between electricity and magnetism. How electromagnetic induction can be easily explained by performing the following experiment:
- Take the magnet from the refrigerator.
- Connect the light bulb to a simple copper coil .
- Move the magnet back and forth inside the coil.
- The lamp will start to light up!
Why did the light come on? By passing a magnet inside the coil, you changed the magnetic field it created. These vibrations were felt by a coil in which an induced current arose.
The secret is electromagnetic induction
How can energy be transferred from one object to another? Wireless charging works on the principle of electromagnetic induction . This phenomenon was first described in 1831 by Michael Faraday , who discovered that if a source of magnetic field is moved through a coil, an electric current will appear in it.
Michael Faraday discovered the relationship between electricity and magnetism. How electromagnetic induction can be easily explained by performing the following experiment:
- Take the magnet from the refrigerator.
- Connect the light bulb to a simple copper coil .
- Move the magnet back and forth inside the coil.
- The lamp will start to light up!
Why did the light come on? By passing a magnet inside the coil, you changed the magnetic field it created. These vibrations were felt by a coil in which an induced current arose.
They are very slow
Of course, everything described above has a number of conventions. Power is one of them.
If you turn a modern wireless charger over and look at the output voltage and amperage values, you will get a power of 5 - 10 Watts. For the most powerful smartphone chargers, this value reaches 20 Watts.
But these are not the same watts that are written on a traditional “wired” power supply. In reality, wireless charging has significantly lower efficiency.
- Wired charging efficiency is 95 – 98%
- Wireless charging efficiency is less than 80%
That is, the difference in charging speed, at best, is 20%. In reality, wireless Qi charging replenishes the battery capacity two or even three times slower.
Small modification of the smartphone
I had a plastic cover at my disposal, but without a built-in Qi charging antenna (experiments showed that the receiver works unstable with it). There is also a universal charging receiver with a native coil. During testing and modifications of the receiver, I slightly tore the flat cord, so I had to replace it.
And I tried to fix the problem with the break by further expanding the hole for the wires. The fastening does not imply a strong bending of the cable at the USB connector, and when the cover is closed, this is exactly what happens. After a little filing of the lid, the wires no longer interfere with the latches. Everything was assembled, nothing sticks out.
