We've heard about wireless charging for years now, but it has its limitations. While the phone is not tied to a cable, it still has to be placed on a pad or stand. What if there was a better way?

Xiaomi says it has the answer with Mi Air Charge, which takes the wireless charging concept to its next logical evolution. It allows users to charge their phones in the air, without the need for cables or pads.

The Air Charge system works thanks to a charging base station and an array of sensors within the phone. Compatible cell phones have a beacon that transmits their location, and the charger can pick it up with an antenna with a five phase interface. Once the base station knows the cell phone's location, the charger uses the other 144 antennas to transmit a millimeter-wide radio wave to the 14 receivers in the cell phone. The cell phone converts those radio waves into electricity, which keeps the battery charged.

While the whole system sounds quite spectacular, there are a few caveats to charging a cell phone from a distance.

First, the charger is quite large, about the size of a small refrigerator or dresser, so space must be allocated. Furthermore, the charging speed of the Xiaomi Mi Air Charge is limited to 5W, a far cry from the 100W wired charging available with some Xiaomi devices.

For comparison, the iPhone 12 series MagSafe wireless charging supports up to 15W. However, this is not true wireless charging either.

We also do not know how efficient this charging method is and how it affects the life of the phone. Early fast and wireless charging systems were notorious for generating excessive heat, which accelerated the normal degradation of the battery.

There is also the issue of range. According to the company, the Xiaomi Mi Charge has a charging range of "a few meters". In other words, it cannot go far from its base.

Still, the prospect of being able to charge phones this way is very exciting. Because the phone is not tied to a single location, it adds a degree of freedom to the entire wireless charging process. There is no need to plug the phone into an electrical outlet or place it snugly on a wireless charging pad.

I don't know when Xiaomi will bring Mi Air Charge to its phones, but it is an encouraging sign that the technology has been made public. I just hope it arrives soon and isn't ridiculously expensive.