TL;DR
  • Xiaomi has revealed that its 200W charging solution drains battery capacity at a significant rate.
  • Roughly two years of charging and discharging cycles will result in the battery degrading to just over 80% capacity.

Xiaomi announced 200W wired charging last month, making for a huge step above even ultra-fast 120W solutions already available in a few phones. The manufacturer says this solution is able to top up a 4,000mAh battery in just eight minutes, but it turns out that this comes at a long-term cost.

Xiaomi posted a Q&A on its Weibo account today, and one of the questions concerned the impact of 200W charging on battery health over time. It turns out that 800 charging and discharging cycles at 200W results in the battery degrading to “above 80%” of its original capacity.

800 cycles corresponds to just over two years, so that means a phone with a 4,000mAh battery will effectively have a 3,200mAh battery (or a little more than this) after two years of charging via this method. Meanwhile, a device with a 5,000mAh battery will essentially have a ~4,000mAh battery after two years of 200W charging.

That’s roughly comparable to Oppo’s 125W charging solution announced last year. Oppo said at the time that 800 cycles with 125W charging will drop the battery capacity to 80%. The firm previously noted that its already brisk 65W solution only dropped the battery capacity to 91%.

More reading: Charging habits to maximize battery life

For what it’s worth, Xiaomi claimed that the Chinese regulatory standard for battery degradation is that 60% capacity should be left after 400 cycles. But that seems like an absurdly low bar for smartphone battery health when people are holding onto their devices for longer than ever. And that standard would mean a phone with a 4,000mAh battery would be reduced to 2,400mAh capacity after roughly a year of charging. That’s barely enough for half a day, with modern phones offering 5G, high refresh rate screens, and other power-hungry features.

Nevertheless, we hope smartphone companies hold off on implementing more 120W to 200W charging solutions until they’ve figured out a way to improve battery degradation. Until then, today’s 40W, 55W, and 65W solutions generally deliver fast speeds without compromising battery health to the same extent.