Posted by Bryan Liu

With Apple finally bringing native wireless charging to its iPhone lineup, more and more people are excited about it and cannot wait to have a try. However someone found it that it’s not as considerate and safe as expected. Let’s see what’s all about.

This is my first phone that supports wireless charging, so I was pretty excited to try it out.

But I noticed that if I put the phone on my charger for the night, it will finish charging sometime in the middle of the night, but the phone will be noticeably warm in the morning, several hours later.

This is not the case when I charge via USB. The phone might get a bit warm while charging, but once finished, the phone will be cool, even if I leave the cable connected for a few more hours.

I'm worried that the wireless charger is trying to force more charge into the battery after it is full, and that this will degrade the battery over time. Is this a valid concern, or am I being overly cautious?

Sounds familiar? Most of you may have encountered the similar if not the same question as the man mentioned above. And the major concern is whether wireless charging impairs our mobile batteries. First let’s figure out how wireless charging works.

How Wireless Charging Works

It is important to understand that wireless charging works completely different than wired charging.

Instead of connecting a cable to a wall outlet or other power source to charge your phone, wireless charging is more convenient and relies on “resonant inductive coupling.” This involves a transmitter coil, which is located in your wireless charging pad, and a receiver coil, which is located in your phone, to create the ‘electronic’ connection. The electric current is transmitted and converted by these two coils which subsequently fill up your phone’s battery.

With a traditional wired charger, the wall adapter takes the AC (alternating current) electricity from your mains supply and converts this to a DC (direct current) flow to charge your battery.

This is usually higher in voltage and the current that is used, which is often unregulated and unsafe.

However, the current used in wireless charging is around 1 Coulomb per second (equal to 1Amp) and this is quite different to wired charging. The transmitter and receiver coils used for wireless charging are located in different devices (see explanation on “resonant inductive coupling” above).

Because it has lower current compared to wired charging along with the separated coils and plastic material (for example, the Qi charger you use) in between, it is actually a more stable and safe charging environment for your battery. Because of this, your phone will remain in better condition over time, and it will also reduce the heat in the battery.

Does the heat directly affect cell phone batteries?

After explaining the working principle, many people will still wonder if the heat generated during the charging would affect the phone, mainly the battery.

Well, in reality, during the charging, it is the semiconductor such as your phone’s back cover that generates heat via the current flow and not the actual lithium-ion battery itself.

How so? Well, lithium that makes up the battery isn’t a semiconductor. Therefore the battery doesn’t really have electricity pass through, which means no heat generated.

So in other words, the heat generated through the wireless charging does not directly affect cell phone batteries.

However, the real enemy is frequent discharge. As is well known, if you keep using the phone while charging, the off and on current cut would damage your phone. Therefore, if you are a frequent phone user, it would be more preferable to use a portable charger, such as Zendure A3 portable charger.

The A3 is one of the most compact and lightweight external batteries in the market for its capacity, thanks to the use of top quality components. With 10,000 mAh capacity, this little thing can easily extend your phone usage 3-4 times. And its unique charge-through function allows you to charge the external battery while it is charging your devices, a feature rarely seen in external batteries. Besides, each port automatically detects your device and fine-tunes the output to charge it at maximum speed (up to 2.1A). Enjoy top charging speed with a "Zen" peace of mind.