Does fast charging harm your phone's battery?

YouTube channel HTX Studio conducted a test to see the impact of fast charging on smartphone batteries. The results show that the difference in capacity after 500 cycles is minimal, regardless of the charging speed.

Photo: HTX Studio

The team at the new YouTube channel HTX Studio conducted an extensive test to determine whether fast charging really does harm battery life. In the 7-minute video, they explore whether it's better to slowly charge overnight or maintain a charge between 30 percent and 80 percent.

Methodology

They used 10 iPhone 12 and 10 iQOO 7 phones, divided into four groups:

Fast charging: iPhone at 20W, iQOO at 120W
Slow charging: iPhone at ~5W, iQOO at 18W
Optimal range: charging only between 30 % and 80 %
Control group: one iPhone and one iQOO were not charged for 6 months

Charging and discharging were automated via an app that activated charging at 5 %. After 500 cycles, the results were:

iPhone 12: 0.5 % less capacity when fast charging
iQOO 7: 0.3 % less capacity in fast charging
Charging between 30–80 %: 4 % more capacity on iPhone, 2.5 % on iQOO

Conclusion

Fast charging doesn't significantly affect battery capacity, while charging within the optimal range offers slight benefits. The video also touches on battery storage, where there was no difference after a week. It concludes with a personal story about a test user's first iPhone.