Although a phone that has these specifications does not yet exist, Xiaomi has obtained from the Chinese authority 3C authorization to market a phone charger capable of providing power of up to 120W via USB-C cable.
This means that a compatible phone cannot be too far from launch, an obvious candidate for this role being the next generation Xiaomi Mi MIX
The new Xiaomi charger could violate USB-C specifications
right the official set of specifications, the USB-C connector now found in most mobile phones can take a maximum power of 100W, in the conditions of a supply voltage of 20 volts. But according to the specifications attached to the most powerful AC adapter created by Xiaomi, USB-C powered phones will take power of up to 120W. Compared to the voltage of 20 volts, it results in no less than 6 Amps that must pass through the oval-shaped connector, without it turning into a carbonized plastic mass.
Even though it has been approved for sale in Asian stores, the new AC adapter it will not be able to be used to its full potential before the end of this year.
Xiaomi has demonstrated since last year a charger capable of sending a power of 100 W, the phone presented at the prototype stage bringing the battery level from 0% charge to 100% in 17 minutes, under the conditions of using a 4000mAh battery. Assuming the scaling is linear, the new 120W could reduce waiting time by another 20%.
Fast charging, harmful to Li-ion batteries
But another smartphone maker, Oppo, has already admitted that the use of fast charging technologies can dramatically reduce their longevity, increasing charging power exponentially amplifying the loss of capacity.
According to OPPO engineers, even at a power of 40W, the use of fast charging technologies can degrade a battery up to 70 percent of the initial capacity after the same number of charges at which a classic QuickCharge implementation, with a maximum power of 15W, would leave 90% from the capacity indicated on the battery label. We can only speculate on the impact of forcing batteries with a power of 120W during fast charging sessions.