iPhone 15 battery doesn’t wear out as fast as Apple thought


iPhone 15 Battery Health and charge cycles
iOS 17.4 will bring in a new Battery Health screen for iPhone showing the number of charge cycles.
Image: Ed Hardy/Cult of Mac

The batteries in the iPhone 15 series are even better than Apple realized. It takes twice as many charge cycles to wear one out than previously thought, greatly expanding the time before the battery needs to be replaced.

We already knew Apple’s latest goes a long time without needing a recharge. And now we know the battery itself is good for years of heavy use while remaining healthy.

iPhone 15 battery takes twice as charge cycles to wear out as Apple previously thought

Diamonds are forever but batteries are not. Li-ion batteries in phones, laptops, etc., inevitably wear out. Each one comes with a limited number of times it can be charged and discharged.

Apple said Tuesday that, for the iPhone 15 series, the number of charge cycles is twice what it thought when these iOS handsets launched in 2023:

“Apple initially said that the iPhone 15’s battery would retain up to 80% of its original capacity at 500 complete charge cycles. Now, the company tells 9to5Mac that the iPhone 15 can retain 80% of its original capacity at 1000 complete charge cycles.”

A charge cycle is completely recharging and discharging the battery. Every time you plug in the device isn’t the start of a new cycle. One starts only after all of the battery’s power has been expended.

Extremely heavy use of an iPhone for a full day might be a complete charge cycle, but that’s quite unusual. People use phones designed to survive 300 to 500 charge cycles for multiple years before the battery starts to wear out. And an iPhone battery that’ll go 1000 charge cycles will last double the time.

The 80% mark is the generally accepted point that a battery is worn out and is ready to be replaced.

Perhaps to highlight how long its products last, the just-released iOS 17.4 beta 4 includes a redesigned Battery Health screen that lists the cycle count (see above). In previous versions, this data was somewhat hidden.

Battery health not battery life

Just so there’s no confusion, Tuesday’s announcement is related to long-term battery health, and has no direct effect on what is traditionally called “battery life.” Apple isn’t claiming that an iPhone 15 will suddenly go twice as long before needing a recharge.

According to Apple, iPhone 15 Pro can stream video for up to 25 hours on a single charge, the same as when the handset first launched. In benchmark testing, iAppleBytes reports that the iPhone 15 lasts for over 11 hours of heavy use. And, with improved battery health, the handsets will be able to keep providing those lengthy battery lives for years to come.

To be clear, the long-term battery health announcement is for the iPhone 15, iPhone 15 Plus, iPhone 15 Pr and iPhone 15 Pro Max, not earlier models.


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