To help get the maximum battery runtime from your device, manufacturers have provided some helpful tips:

• Use battery saver whenever possible
• Reduce your screen brightness
• Close any applications or programs that are not in use

Most devices include a 'battery saver' setting to enable far greater battery run times, at a cost of some device performance. 
Depending on the task you are performing, the extra performance may not even be needed or noticeable with battery saver on.

Click the titles or images below to be taken to the manufacturers help sites.

Windows

Apple

Android