Some controversy occurred a few years ago when Apple tried to extend the battery life of its phones with something called performance throttling, or performance management. To conserve battery life and keep your iPhone running, performance management throttles your phone's performance. If you turn it off manually, your iPhone's battery will run out very quickly because it will be operating very close to its limits.

Apple recommends these simple steps for extending your phone's battery life:

Every major iOS upgrade comes with new battery-saving features.

On average, keep your phone between 16 and 22 degrees celsius. Anything above or below that might damage your lithium battery.

You should avoid excessive heat when charging your phone. Some cases or surfaces can cause your phone to heat up, which can damage the battery. Make sure your phone remains cool while it is charging.

The drain from a fully charged battery could also damage your phone, so keep it half-charged. Don't completely drain your battery because it could fall into deep discharge, which will cause significant damage.

The brightest screen settings tend to drain your battery quickly, forcing you to go through charge cycles quickly and losing battery life.

You can check your background activity in Settings > General > Background Refresh. Too many apps running in the background can drain your battery.