With the arrival of the iPhone 15, Apple added the option to charge the battery up to 80 percent, but does that help?
Does charging your iPhone to 80 percent help?
The idea is that if you never charge your iPhone above 80 percent, the battery will last longer. But is this really true? To check, MacRumors an iPhone 15 Pro Max from September 2023 held at the 80 percent limit until now. That iPhone’s battery is currently at 94 percent with 299 cycles. For much of 2024, the battery level remained above 97 percent, but in the last few months it started to drop more rapidly.
The iPhone has always been at that 80 percent limit and the setting has never been turned off or adjusted. There were days when the battery would die because charging was not possible for a large part of the day. So it wasn’t always convenient to keep the battery at 80 percent, but there were also days when it didn’t matter much.
This is how charging went
Every now and then the iPhone would suddenly decide not to charge to 80 percent, but still to 100 percent. That’s something Apple built in to ensure the battery level stays calibrated. The iPhone charged primarily via USB-C and occasionally via MagSafe. The split between wired and wireless charging is about 70/30.
The battery level was often quite low on the next charge and the iPhone was not often on the charger for long periods of time. Charging usually took place in a room of about 22 degrees. This is important because temperature is a factor that can affect the life of the battery. In addition, wireless charging is warmer than wired charging.
These are the figures after one year
It seems that limiting charging to 80 percent has indeed kept the maximum battery capacity higher, but the difference is not huge. The battery now has a capacity of 94 percentat 299 cycles. Compared to two identical iPhones that did not use the 80 percent limit: 87 percentat 329 cycles and 90 percentat 271 cycles.
It’s possible that the real benefit of an 80 percent cap won’t be apparent for two or three years, rather than just one. Time will tell. There’s also an option to set a 90 percent charging cap, which could be more feasible than 80 percent for many people, especially if you have an iPhone with a small battery.
Download the iPhoned app
