KEY BATTERY HOGS

01 SCREENS

LCD screens have to be powered themselves, but need a backlight too. The result is that they draw a lot of power, especially at brighter settings. OLED screens (used on iPhone X and Apple Watch) don’t require a backlight, so are kinder on batteries.

02 MOBILE INTERNET

Streaming data at high speeds between your phone and the nearest tower requires a lot of energy. More modern versions are more efficient, but are still major battery killers.

03 INTENSIVE APPLICATIONS

Processors are a bit like car engines, in that they use more fuel the harder you push them. Any task that requires a lot of processing power over a long time — such as converting a video, or the way a game is constantly using a graphics chip — will use a lot of battery power.

04 WI-FI

There’s some debate over whether mobile internet is more of a battery drain than Wi-Fi. Either way, sending data over the air from your device to your router (and back) will have an impact on battery life.

05 HARD DRIVES

Spinning a magnetic disk at thousands of revolutions per minute uses more power than flash storage.

06 GPS

Communicating with satellites in low Earth orbit turns out to be pretty taxing — constant location searching will quickly drain a device’s battery.