Smartphone charging systems are gaining in power and therefore in speed, but the degradation of the battery is also accelerating.
Fast charging over 50W has become almost common for high-end smartphones, and capacities are climbing (at least technically) to over 100W.
Recently, the Xiaomi Group demonstrated 200W wired charging on a modified Xiaomi Mi 11 Pro allowing full charge in just 8 minutes and 120W wireless charging charging the battery fully in 15 minutes.
These features have the advantage of ensuring the autonomy of the smartphone without going through a significant increase in the battery capacity, so as to keep devices thin.
But these very fast charging technique techniques place a particularly strong stress on the battery which risks degrading more quickly. When asked about the subject, Xiaomi indicated that after 800 charge / discharge cycles, the capacity remained above 80%, which represents approximately two years of operation.
Android Authority notes that another Chinese manufacturer, Oppo, had given an indication of 80% capacity for 800 cycles at 125W and 91% after 800 cycles at 65W. Fast charges from 50 to 65W would therefore remain for the moment the best way to ensure the maintenance of the battery capacity over a long period, while waiting to find solutions to limit the degradation at higher power (such as batteries). in several cells, with less power distributed to each).
This is undoubtedly also the reason why the most powerful loads are the subject of regular demonstrations but are still quite rarely integrated, apart from exceptional products.