Everything You Need to Know About Wireless Charging

Wireless charging has become a thing. In many phone models, you can either charge it natively by plopping it on a wireless charging port, or you can attach a module that lets you achieve the same effect. For those of you who are a bit frustrated by the thought of fiddling with cables to charge your phone on a daily basis, wireless charging has presented a viable alternative. But how much do you really know about the charger you’re using at your home or at a cafe?

How It Works


When using the term “wireless charging,” it somehow seems like you will be able to charge your phone at any distance from the charging unit. It’s misleading but a necessary evil that provides a simpler terminology to understand. The reality is that “wireless charging” is actually magnetic induction charging.

Magnetic induction chargers, as the name implies, have a strong electromagnetic coil in the center that generates a field. The moment you place your device on a charging surface, the charger’s magnetic coil will turn on, and your device will charge by utilizing the magnetic field generated by it. The device’s end functions in reverse, taking the magnetic field and converting it into usable energy.

Please note that this is different from the magnetic charging cables found in some Mac models. These cables use magnets for attaching to their ports, but pass current from point A to point B through conduction, not induction.

How Fast Does Your Phone Charge?

The speed of a phone’s charging cycle depends entirely on amperage and voltage. If you multiply both, you end up with the effective wattage in power being transferred from the charger to the phone. A 12-volt charger delivering 500 milliamps of nominal current will charge at 6 watts of nominal power. Phone battery capacity is measured in milliamp-hours (mAh). On the other hand, the average charger will show you how much voltage in direct current (DC) it will deliver, and at what amperage it will deliver it.

Typical wall chargers will deliver 1 amp of nominal current at 5 volts of tension. This charges a 3,000 mAh battery in roughly 3.6 hours. Most wireless chargers will also follow this guideline (5 volts of tension), but will lower the amperage slightly (the highest I’ve seen is 0.65 amps). Expect your phone to take longer to charge in this instance. To get a feel for how long your phone will take to charge on a wireless charger, check its amperage and compare it to the 1-amp nominal current delivered by the typical wall charger.

There Are Other Devices That Use Induction Charging

Electric Toothbrush

Wireless charging, as it is understood today, wasn’t just some new thing that came along with the advent of smartphones. If you have an electric toothbrush or a “wet & dry” shaving machine, you’re probably using that technology right now. In order to avoid short-circuiting, the charging ports of devices that expect to have wet surfaces are protected behind the device’s thick casing. This makes induction the only way that charging could occur.

Is Hijacking Your Phone Through the Wireless Charger Possible?

You may have heard of cases in which people’s phones were hacked and information was stolen through the charger in a public place. A new concern is on the rise as more restaurants and other public venues are offering free wireless charging to individuals with smartphones. Can the same thing happen through this new kind of charger?

The answer (so far) is a resounding “no.” The reason why wired charging stations were able to steal information was because it relied on the phone’s USB port (all five wires). This allowed some charging stations to act as a computer that would interact with the phone. With wireless charging, the induction coils have only one purpose: Turn on the magnet so the phone can chug some juice.

Of course, that all may change if phone manufacturers decide to allow their devices to use wireless chargers as information exchange points. When that time comes, this will become a legitimate concern.

If you have any more questions about wireless charging, or have awesome facts to share, be sure to speak your mind in a comment!

Miguel Leiva-Gomez
Miguel Leiva-Gomez

Miguel has been a business growth and technology expert for more than a decade and has written software for even longer. From his little castle in Romania, he presents cold and analytical perspectives to things that affect the tech world.

Subscribe to our newsletter!

Our latest tutorials delivered straight to your inbox