In September 2023, Apple launched a new feature with the iPhone 15, allowing users to set a maximum To charge the battery At 80%. This step is intended to extend the battery life in the long term. In a year-long study, they implemented this feature on a device IPhone 15 Pro Max To monitor its actual impact on battery performance and lifespan, what were the results?

From iPhoneIslam.com, the phone screen displays the iPhone battery charging settings with the option to set a maximum charge limit between 80% and 100%, including a recommended charge limit of 80% to help preserve battery life, all improved by the new iOS 18.

Experiment results after one year

From iPhoneIslam.com, a smartphone showing 75% charge with the text “One Year Later” in the background and colorful flower shapes, highlighting the iPhone’s battery charge.

After 12 months of continuous use with the 80% charge limit enabled, the battery capacity reached 94% after 299 charge cycles. It is noticeable that the battery level remained above 97% for most of 2024, but it started to decrease faster in the last two months.

Usage challenges

The experience wasn’t without its challenges. Some days, students experienced battery drain quickly, especially when they didn’t have access to a charger for extended periods. Sometimes, it was necessary to use an additional external battery to charge the iPhone to keep it running. While it wasn’t always convenient, there were days when it didn’t significantly impact the user experience.

It is worth noting that Apple has programmed the iPhone to sometimes charge up to 100% randomly, in order to maintain accurate battery level calibration.

Shipping methods used

From iPhoneIslam.com, a close-up of a smartphone screen showing app icons, with a charging cable near the charging port. The device runs iOS 18 charging, which provides multiple options and improved performance for the iPhone battery.

During the experiment, the battery was primarily charged via USB-C wired charging, with the MagSafe charger occasionally used. The usage rate was approximately 70% for wired charging versus 30% for wireless charging. The participants often waited until the battery was significantly depleted before recharging, and avoided leaving it on the charger for extended periods of time. Most charging was done at a constant temperature of around 22°C (72°F).

Compared to other devices

To make an objective comparison, the study's authors monitored the results of other iPhone 15 Pro Max devices that did not meet the 80% limit, and the results were as follows:

The first device: Current battery capacity is 87% after 329 charging cycles.

The second device: Current battery capacity is 90% after 271 charging cycles.

Although the data available for comparison is limited, it seems that limiting the charge to 80% helped preserve battery capacity and percentage better than other devices. However, the difference is not significantly large. The iPhone in the study retained an additional 4% of battery capacity after 28 additional charge cycles, which raises the question of whether enduring the 80% limit for a full year is worth it after all this suffering to gain only 4% of battery life?!

Future outlook

The real benefits of this feature will likely be seen after two or three years, not just one, so the team will continue to apply this limit for a longer period to study the long-term impact.

For the iPhone 16 Pro Max, the team also enabled the 80% limit, but there were questions about whether it was worth continuing this experiment given the modest results obtained last year. Will thermal changes in the iPhone 16 models lead to a difference in results? That's what the study will find out over time.

Other options and recommendations

Apple also offers the option to limit the charge to 90%, which may be more practical for many, especially those with smaller battery phones. Here are some tips to keep your battery healthy:

◉ Avoid exposing the phone to excessively high or low temperatures.

◉ Use original chargers approved by the manufacturer.

◉ Try to keep the battery level between 20% and 80% as much as possible.

◉ Keep your operating system up to date to take advantage of power management improvements.

◉ Reduce the use of battery-intensive apps when you don't need them.

Conclusion

After a year of testing, it seems that the 80% charge limiting technique does have a positive effect on battery life, but not as much as some might expect. However, the cumulative effect over several years could be more noticeable and of great benefit.

We encourage you, our valued iPhone users, to share your personal experiences, including current battery capacity and number of charge cycles if possible, to help build a clearer picture of the effectiveness of this feature. We also encourage you to consider whether Apple’s charging restrictions are worth it for your personal needs.

Ultimately, battery management is a matter of balancing daily performance with long-term battery life. As technology continues to evolve, we expect more innovations in this area to improve user experience without sacrificing battery life.

Do you use the 80% or other charging limit on your iPhone? And how does it work for you? Let us know in the comments.

Source:

macrumors

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