Here's why Xiaomi hasn't delivered a 100W charging phone just yet

Xiaomi made waves almost a year ago when it revealed that it was working on 100W charging technology, capable of charging a 4,000mAh battery in 17 minutes. The company said Redmi phones would get the tech first, but we haven’t heard anything else since then.

Now, Redmi general manager Lu Weibing has taken to Weibo to reveal five technical difficulties associated with 100W charging (and fast charging in general).

Major battery degradation

Perhaps the biggest consideration is battery capacity, with the Redmi executive saying faster charging results in greater capacity loss. And this is a big issue when you’ve got 100W charging.

“According to preliminary estimates, the capacity of a 100W fast charge battery is about 20% less than that of a 30W PD fast charge. In short, 5,000mAh becomes 4,000mAh,” Lu said according to a machine-translated version of his post.

In other words, it seems like 100W charging requires a big battery right now in order to off-set the degradation. Otherwise, your 4,000mAh battery will eventually become a 3,200mAh battery due to charging-induced degradation.

This isn’t the only technical difficulty cited by the Redmi executive, as he also points to the technical architecture, charger compatibility, charging protections throughout the device (e.g. for battery, motherboard etc), and general performance as four other hurdles to overcome.

Nevertheless, the Xiaomi executive says 100W charging has “reached the early stage of mature production and can be expected in the future.” So it definitely sounds like we can still expect a 100W smartphone, but it will probably have a massive battery to fight off the effects of degradation.