Your phone's battery, honestly explained

Phone batteries come with a lot of folklore. Some people drain theirs to zero every night. Others unplug the moment it reaches 100%. Most of these habits come from older battery types and no longer apply.

Modern phones use lithium-ion batteries, and they wear out in predictable ways. Here is what matters and what does not.

What wears a battery out

• Heat, especially charging while the phone is hot, for example in a car or under a pillow.

• Spending long periods at 100% or near 0%.

• Fast charging when the phone is already warm.

• Simply getting older, which happens whatever you do.

Heat ages a battery faster than any charging habit.

What does not matter much

Charging overnight is fine on most recent phones, which learn your routine and hold the charge at around 80% until shortly before you wake. Using a different brand of charger is fine if it is a reputable one. Letting the battery drain to zero on purpose does not help and slightly harms it.

How long should it last?

After about two to three years of daily use, most batteries hold roughly 80% of their original charge. If yours is much worse, the phone’s battery health setting will tell you, and a replacement is usually cheaper than a new phone.

The simplest advice: keep it cool, turn on optimised charging, and stop worrying about the rest.

A quick checklist

• Turn on optimised or adaptive charging in your settings.

• Avoid charging in direct sun or on a hot car dashboard.

• Remove thick cases if the phone gets warm while charging.

• Replace the battery, not the phone, when health drops below about 80%.

Battery replacements have become easier and cheaper in many countries, and some manufacturers now publish repair guides and sell parts directly. A new battery can make an older phone feel new again, and it is far better for the environment than buying a replacement handset.

As for the habit of closing all your apps to save power, most modern phones manage background apps well by themselves. Reopening an app from scratch can actually use more energy than resuming it.