Everything you need to know about wireless phone charging

What is wireless phone charging?

Wireless charging lets you charge your smartphone’s battery without a cable and plug.

Most wireless charging devices take the form of a special pad or surface on which you place your phone to allow it to charge.

Newer smartphones tend to have a wireless charging receiver built in, while others need a separate adapter or receiver to be compatible.

How does it work?

1. Inside your smartphone is a receiver induction coil made of copper.

2. The wireless charger contains a copper transmitter coil.

3. When you place your phone on the charger, the transmitter coil generates an electromagnetic field that the receiver converts to electricity for the phone battery. This process is known as electromagnetic induction.

Because the copper receiver and transmitter coils are small, wireless charging only works over very short distances. Household products such as electric toothbrushes and shaving razors have been using this inductive charging technology for many years already.

Obviously, the system isn’t completely wireless as you still have to plug the charger into the mains or a USB port. It just means you never have to connect a charging cable to your smartphone.

What’s ‘Qi’ wireless charging?

Qi (pronounced ‘chee’, the Chinese word for ‘energy flow’) is the wireless charging standard adopted by the largest and most well-known technology manufacturers, including Apple and Samsung.

It works the same as any other wireless charging technology—it’s just that its rising popularity means it has quickly overtaken its competitors as the universal standard.

Qi charging is already compatible with the latest models of smartphone, such as the iPhones 8, XS and XR and the Samsung Galaxy S10. As newer models become available, they too will have a Qi wireless charging function built in.

CMD’s Porthole Qi Wireless Induction Charger uses Qi technology and can charge any compatible smartphone.

Which smartphones are compatible with wireless charging?

The following smartphones have Qi wireless charging built in (last updated June 2019):

Make

Model

Apple

iPhone XS Max, iPhone XS, iPhone XR, iPhone 8, iPhone 8 Plus

BlackBerry

Evolve X, Evolve, Priv, Q20, Z30

Google

Pixel 3 XL, Pixel 3, Nexus 4, Nexus 5, Nexus 6, Nexus 7

Huawei

P30 Pro, Mate 20 RS Porsche Design, Mate 20 X, Mate 20 Pro, P20 Pro, Mate RS Porsche Design

LG

G8 ThinQ, V35 ThinQ, G7 ThinQ, V30S ThinQ, V30, G6+ (US version only), G6 (US version only)

Microsoft

Lumia, Lumia XL

Motorola

Z series (with mod), Moto X Force, Droid Turbo 2

Nokia

9 PureView, 8 Sirocco, 6

Samsung

Galaxy Fold, Galaxy S10, Galaxy S10+, Galaxy S10E, Galaxy Note 9, Galaxy S9, Galaxy S9+, Galaxy Note 8, Galaxy S8 Active, Galaxy S8, Galaxy S8+, Galaxy S7 Active, Galaxy S7 Edge, Galaxy S7, Galaxy S6 Edge+, Galaxy S6 Active, Galaxy S6 Edge, Galaxy S6

Sony

Xperia XZ3, Xperia XZ2 Premium, Xperia XZ2

Most recent smartphones and tablets are compatible. If your smartphone is an older model not listed above, you’ll need a wireless adapter/receiver.

Plug this into the Lightning/Micro USB port of your phone before you place the device on your wireless charger pad.

Can I use a wireless charger with any phone?

Providing they support the same wireless charging standard (e.g. Qi), you can use any wireless charger with your smartphone. They don’t need to be made by the same manufacturer—you can use a Samsung wireless charger with an iPhone, for example.

Is wireless charging faster than wired charging?

No—not at the moment.

Wireless chargers are rated by output in watts. Most current chargers provide around 5W, with a few capable of 10W–15W. Used to charge an iPhone 8 or Galaxy S10, for example:

A 5W wireless charger will take around:

3–4 hours

A 5W wired charger will take around:

2.5 hours

This is despite the fact that many newer smartphones incorporate fast-charging technology that enables them to draw more power when charging. Older models will charge even more slowly.

Wireless charging speeds can increase when phone manufacturers update their operating systems accordingly. But the speed still depends on factors such as:

• air temperature
• the phone’s battery level when set to charge
• where the phone is placed on the charger pad
• the age of the phone and battery

Generally, to guarantee your phone will charge faster, you need to use a cable.

How far away can the phone be when using a wireless charger?

Although there are companies working to make wireless charging at a distance possible, at present you need to place your phone on top of the charging pad for it to work.

Is wireless charging bad for my phone battery?

All rechargeable batteries begin to degrade after a certain number of charge cycles. A charge cycle is the number of times the battery is used to capacity, whether:

• fully charged then drained completely
• partially charged then drained by the same amount (e.g. charged to 50% then drained by 50%)

Wireless charging has been criticised for increasing the rate at which these charge cycles occur. When you charge your phone with a cable, the cable is powering the phone rather than the battery. Wirelessly, however, all the power is coming from the battery and the charger is only topping it up—the battery isn’t getting a break.

However, the Wireless Power Consortium—the global group of companies who developed the Qi technology—claim this isn’t the case, and that wireless phone charging is no more damaging than wired charging.

For an example of charge cycles, batteries used in Apple iPhones are designed to retain up to 80% of their original capacity after 500 full charge cycles.

Can wireless charging overcharge my phone battery?

You can’t overcharge a smartphone battery, but keeping it charged to 100% all the time might cause it to degrade more quickly.

Should I leave my phone on the wireless charger overnight?

Smartphones are built to prevent their batteries from being overloaded. If you leave your phone to charge overnight, it will reach 100% capacity then stop, although it will continue to top up the battery every time it falls to 99%. This can shorten the battery’s lifespan somewhat.

Do wireless chargers work when the phone has a case?

Some phone cases (such as wallet cases) might be too thick for wireless charging to work properly. Cases made of plastic, silicone, rubber and leather don’t seem to affect wireless charging too much.

Do car mounts interfere with wireless charging?

With some car mounts, you’re required to attach a magnetic metal plate to the back of your phone (usually in between your case and phone) to be able to fix it to the mount. Because metal is too thick for the electric current to reach the battery, your phone is unlikely to charge properly.

Can I use a wireless phone charger in the car?

If your car doesn’t come with wireless charging already built in, you simply need to install a wireless charging device inside your vehicle. There’s a wide range of designs and specifications, from the standard flat pads to cradles, mounts and even chargers designed to fit a cup holder.

Can I charge more than one phone at the same time?

This depends on the charger. Some have two or three pads for multiple devices, but most have just one and can only charge a single phone at a time.

What are the pros and cons of wireless charging?

Pros

• Less wear and tear on cables
• Convenient
• Easy to do
• Looks neater—no wires
• Great compatibility
• Frees up headphone port on iPhones

Cons

• Inefficient in terms of electricity use
• Can’t move your phone during charging
• Might not work through phone case

Want a wireless charger for your phone?

Click here to see CMD’s Porthole Qi charger

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