It may not have the world’s first under-screen camera, a title the ZTE Axon 20 5G is claiming, but the Xiaomi Mi 10 Ultra still shocked the mobile world with its insane charging speeds. As if the 120W wired charging weren’t enough, the phone even boasted of 50W wireless charging, more than three times the market average, and promising to charge the Mi 10 Ultra from zero to full in just 40 minutes. Naturally, that kind of unbelievable technology will raise concerns and questions and Xiaomi was only too happy to explain some of the details to those willing to listen.
Charging systems have to take into account multiple factors in order to maintain safety while still providing the best power efficient to power up batteries as fast as possible. Heat is the number one enemy of charging and it’s produced from efficiency losses and, in turn, poses a danger to the smartphone’s and the user’s safety.
Xiaomi’s solution to the first issue is to adopt a new double charge pump setup that controls the voltage that’s passed from the wireless charging coils to the battery. Instead of the usual series arrangement, the Mi 10 Ultra puts the pumps in parallel so that efficiency losses don’t stack up and are “paid” only once. In practical terms, a charging efficiency of 97% is really only 97% and not lower.
Additionally, Xiaomi was able to squeeze out 98.5% efficiency from these new charge pumps thereby minimizing not only the loss but also the heat generated. This is assisted by other strategies like using a graphene-based cooling system as well as splitting the battery into two cells.
In a nutshell, Xioami is explaining how its rather radical fast charging technologies aren’t exactly outlandish or over-the-top, which would have raised red flags as far as consumer safety goes. Whether these will have unwanted side effects in the long run, however, won’t be seen until after a few years in the Xiaomi Mi 10 Ultra’s lifetime.