Imagine a world where your device’s battery quietly charges all on its own. Your Bluetooth stereos. A pair of hearing aids. The smartwatch tracking your vitals. The phone in your pocket.
The ability to send an electric current through the air, from one location to another, may not be a new idea but it has certainly taxed the minds of engineers for many years – that is the ability to transmit power wherever it is required and without the need for wires.
Showcased for the first time during CES 2019, charging batteries over the air, without any wires grabbed eyeballs during the event. Almost two years later, we have brands like Xiaomi, Motorola, and Oppo, ready with their over the air chargers. Recharging phones in the air, without needing any cables or pads to do it, seems like the next big innovation in the field of wireless charging.
As tech brands take their efforts to offer contactless devices to the next level, how efficient is the technology going to be? Currently, wireless chargers need to be in contact with the device in order to charge the batteries. However, with the new technology, manufacturers are looking to get rid of the contact factor as it has been proved deadly viruses can survive for longer durations on metal surfaces.
Let’s take Xiaomi’s AirCharge for reference. Xiaomi says it has the answer with Mi Air Charge, which takes the concept of wireless charging to its next logical evolution. Recharging phones in the air, without needing any cables or pads to do it.
The Air Charge system works thanks to an array of sensors inside a charging base station and your phone. Compatible phones have a beacon that transmits its location, which the charger can pick up with five phase interface antennas. Once the base knows where your phone is, the charger uses 144 other antennas to transmit millimeter-wide waves towards 14 receivers inside the phone. The phone then converts the waves to electricity, which keeps the battery recharged.
The whole system sounds quite spectacular, though there are some caveats to recharging your phone from a distance.
For comparison, the iPhone 12 series MagSafe wireless charging supports up to 15W. But, again, it’s not true wireless charging.
We also don’t know how efficient this method of recharging is, and how that’s going to affect the longevity of your phone. Early fast and wireless charging systems were notorious for producing excess heat, which would speed up the usual degradation of the battery.
There’s also the question of range. Xiaomi Mi Air Charge has a range of “several meters,” according to the company. So you can’t stray too far from the base.
Still, the prospect of recharging your phone like this is quite exciting. It adds some freedom to the whole wireless charging process because your phone isn’t tied to a single spot. Your handset doesn’t need to be plugged into a power outlet, or perfectly positioned on a wireless charging pad.
Wireless charging will benefit both the accelerating digitalization of industry, along with the rollout of the Internet of Things (IoT). As a consequence of smaller sensors, it will be possible to develop more streamlined IoT products, allowing the development of devices with more complex and varied functionalities.
Smaller batteries could also mean devices can be both lighter and have room for other components and capabilities. Most of the volume and weight of any device comes from its battery.
Here’s how Xiaomi has described the mechanics of its new tech:
On the smartphone side, Xiaomi has also developed a miniaturized antenna array with a built-in “beacon antenna” and “receiving antenna array”. Beacon antenna broadcasts position information with low power consumption. The receiving antenna array composed of 14 antennas converts the millimeter-wave signal emitted by the charging pile into electric energy through the rectifier circuit, to turn the sci-fi charging experience into reality.
Currently, Xiaomi remote charging technology is capable of 5-watt remote charging for a single device within a radius of several meters. Apart from that, multiple devices can also be charged at the same time (each device supports 5 watts), and even physical obstacles do not reduce the charging efficiency.
The company said it has self-developed an isolated charging pile that has five phase interference antennas built-in, which can “accurately detect the location of the smartphone.”
A phase control array composed of 144 antennas transmits millimeter-wide waves directly to the phone through beamforming, the company said, adding that “in the near future” the system will also be able to work with smartwatches, bracelets, and other wearable devices. At a time when users are looking for ways to reduce their energy consumption, these air chargers can come in handy. As the technology becomes more efficient at powering devices, the adoption of wireless power could become an everyday occurrence – much mike logging on to your local Wi-Fi.