Why you shouldn't charge your phone to 100%, according to experts
(NEXSTAR) — Waking up and realizing you forgot to plug your phone in may be anxiety-inducing for some. However, according to experts and phone manufacturers alike, not charging your phone to 100% overnight, or ever, may be for the best.
Battery life is a frequently cited reason for upgrading from an old smartphone. While replacing a battery has become easier in recent years, so has maintaining its health.
Most phones now come with features intended to improve the battery’s lifespan.
iPhone users may already be familiar with the “Optimized Battery Charging” feature. Google Pixel users have a similar charging optimization feature (on Pixel 6a devices and newer).
You may have also seen a notification on your phone regarding charging based on your habits. For example, your iPhone may charge to 80%, then pause charging until shortly before your alarm goes off in the morning, giving itself just enough time to reach 100% ahead of your usual wake-up time.
Apple and Google both recommend, though, that you don’t always charge your phone to 100%.
Why is 80% the recommended charging maximum?
It has to do with your phone battery’s chemical age, according to Apple. While several factors can impact its chemical age — like its temperature and charging pattern — the batteries will become less effective the more chemically-older they become. Heat, which occurs while charging, and full charge cycles add to that aging, James Herman, founder of MobileTech Addicts, told tech outlet Lifewire.
The aforementioned features can help you improve your battery’s lifespan as they aim to reduce the wear on it.
Newer iPhones (all 15 and 16 models) and Pixels (6a and later) allow users to cap charging at 80%, a level both manufacturers say should be enough to last the phone all day. (Apple and Google note, however, that your device may occasionally charge to 100% “to ensure accurate battery capacity readings.”)
Battery health is subsequently tracked based on a charge cycle — which is how many times you use 100% of the battery’s capacity. So if you use 50% today, charge your phone completely tonight, and use 50% of your battery tomorrow, that would count as an entire cycle. More cycles can, at times, add more wear to your battery.
An iPhone 15 Pro Max user reported on a MacRumors forum that, after one year of using the 80% charging limit, their battery's maximum capacity, or its capacity compared to when it was new, had dropped to 94% over 299 charging cycles. They compared that with two other iPhone 15 Pro Max users, who were at 87% and 329 cycles and 90% at 271 cycles.
While the differences were minor, it suggests that charging to 80% and not any further may prove beneficial for the phone’s battery in the long run.
How can you extend your phone’s battery health?
If you have an iPhone, you can find the charging optimization features under Settings, then Battery, then Charging. On the Pixel, you can find the Adaptive Battery option under Settings, then Battery, then Battery Saver.
Your device likely also offers features like lower power mode — while it is likely set to turn on once your battery drops to a certain level, it can be manually activated at any time. Screen sleep time and brightness can be reduced; location services can be turned off for certain apps; and other features can be adjusted to reduce battery usage as well.
If you prefer to charge your phone to 100%, don’t sweat it — most devices have charging optimization features that will automatically kick in to help extend your battery’s lifespan.