Oh Mi: Xiaomi shows off 80W wireless charging, claims battery fully fat again in under 20 minutes

Xiaomi has demoed its latest 80W wireless charging technology that it claims can fully replenish a 4000mAh smartphone battery in 19 minutes.

The tech — dubbed, somewhat predictably, Mi Wireless Charging — is not yet available on a commercial device, although Xiaomi showed it in action on a modified Mi 10 Pro.

Wireless charging has traditionally sacrificed speed in favour of convenience. While it’s possible to buy phones with 65W USB-C charging (like the recently released Realme 7 Pro and Oppo Reno 4 Pro), wireless charging typically performs at a fraction of that — usually around the 15W mark, and often less.

There are exceptions like the OnePlus 8 Pro, which shipped with 30W wireless charging capabilities.

Where things get really interesting is when you think about what you can do with super-fast wireless charging. It opens the possibility of completely port-less phones, such as Vivo’s intriguing 2019 Apex concept phone, which it demonstrated at Mobile World Congress 2019. With USB-C out of the picture, Vivo was able to adopt a unibody design, with the chassis enveloped in an unbroken sheath of glass. Apple has reportedly considered using this form-factor, too.

But let's not herald the advent of a totally cord-free future just yet: wireless charging is horrendously inefficient when compared to standard cabled charging, with vastly more energy dissipated as heat or RF energy. This wastage increases when the coils on the phone and the charger are not perfectly aligned.

Moreover, some wireless chargers get so hot during use, they cannot be passively cooled, and come with a built-in cooling fan. This increases power consumption further. At scale, the use of inductive charging promises to increase the carbon footprint associated with owning a smartphone.

Still, wired charging has its own ecological disadvantages. There’s an inevitable environmental cost to producing a USB-C cable: from obtaining the raw materials, to transporting them, to manufacturing the cable, and finally, to shipping the product to retailers.

In light of this, the European Commission is contemplating forcing smartphone manufacturers to un-bundle cables and chargers from their devices. No decision has been made, although some vendors have seemingly decided to pre-empt any action, with Apple removing the charger and headphones from the latest iPhone 12 series. ®