Is it safe to charge your phone overnight?
The answer is more nuanced than it’s ever been.
When you drift off to sleep, you plug your phone into the charger beside your bed, allowing it to charge for several hours, likely exceeding the necessary duration to reach 100% battery. You might have thought that leaving your phone charging overnight could harm its battery, as the chemistry of lithium-ion batteries degrades over time with repeated charge and discharge cycles.
Traditionally, the advice was to avoid overnight charging and keep the battery between 20% and 80% for longevity. However, recent advancements in battery management systems in modern phones have made the overnight charging debate more complex.
Today, smartphones have sophisticated battery health management and charging controls. For example, Apple introduced Optimised Battery Charging in 2019, which learns a user's charging habits and delays charging further when the phone is expected to be connected for an extended period overnight. Similarly, Samsung and Google Pixel phones offer features like Adaptive Charging and Sleep Time Protection, which charge the battery up to 80% while you sleep and complete the charge shortly before you wake up.
The latest iPhone 17 has even more advanced adaptive power mode, adjusting power usage to maintain battery health throughout the day.
Manufacturers no longer strictly enforce an 80% charging limit. Samsung allows users to set battery protection levels at 80%, 85%, 90%, or 95%, while Apple's recent iPhones offer similar options in 5% increments from 80% to 100%. Pixel 6a and newer models can be set to a maximum charge of 80% if preferred.
Choosing a lower charging limit can extend battery lifespan but means less daily battery capacity, which may be acceptable if you can charge your phone daily. Conversely, allowing the phone to charge to 100% when needed provides more usage time. Regardless of your chosen limit, it's crucial to keep the phone away from excessive heat, which can accelerate battery degradation and can also be managed by modern phones' built-in temperature controls.
While phone batteries still experience wear over time, these smart charging features can help prolong their lifespan by mitigating some of the aging effects. Thus, for most users, charging your phone overnight is generally safe with these modern features in place, but always monitor your phone's temperature to ensure it remains within safe limits.
Written by urgent.news from The Conversation AU's reporting — not their text. Machine-written — may contain errors; check the original before relying on it.
