What is battery capacity (mAh)?

Battery capacity (mAh) is the number shown in a phone's specs that tells you how much charge the battery can hold. mAh stands for milliampere-hour, and it works a bit like the size of a car's fuel tank: the bigger the tank, the longer the engine can run. However, capacity alone does not decide how long the phone lasts, because screen size, processor power and app usage also affect how quickly the battery drains.

In daily use, a larger capacity usually means more hours before you need to charge. A 4000 mAh battery may last a full day for a normal user, while 5000 mAh or more suits people who use their phone heavily, play games or take a lot of photos. Still, a phone with a large screen and a powerful processor can drain a 5000 mAh battery faster than a smaller, simpler phone with the same capacity.

When buying, look for a capacity that matches your habits: 4000 to 4500 mAh is fine for average use, and 5000 mAh or more is better for heavy use. But do not focus on the number alone. Also consider screen efficiency, charging speed and fast-charging support, because a phone with a smaller battery and an efficient screen may last longer than one with a bigger battery and higher power consumption.