Xiaomi did a Q&A on its recently unveiled 200W charging technology and was asked if the hypercharging is safe for the battery.
Xiaomi’s answer describes in a number of slides how it manages to dissipate heat during 200W charging, and what kind of power you can expect from the super fast filling. According to their estimates, the battery should lose just under 20% of its capacity after 800 cycles, which is over two years if you do a full charge every day. If you go further between charges, it can stretch even more.
Doing fast math for a 5,000 mAh (as for the Mi 11 Ultra) means it will carry 4,000 mAh of its original 5,000 mAh after 800 cycles.
Xiaomi says the Chinese government requires at least 60% after only 400 cycles, which Xiaomi greatly exceeds.
And here’s another fact – no matter how slowly you charge your battery, it will deteriorate after 800 cycles. Heat is the biggest culprit in battery degradation, so whether you keep your phone tied to a 5W charger for 5 hours or 200W charger for 10 minutes, it is the amount of heat your battery handles that reduces charging the fastest. And all batteries lose capacity after many years of use, so given the insane speeds, the numbers quoted by Xiaomi actually sound very reasonable.