Check what is draining the battery the most

Go to Settings > Battery to see a breakdown of what's consuming your phone's battery

Applications and features will display in a descending list of battery consumption

If you see an application or feature you barely or never use, you'll can uninstall the app or turn off the feature

Reduce email, Facebook etc refresh frequency

Set your various messaging apps to "manual" for the refresh frequency

This will instantly extend your device's battery life by a significant amount

Once you see what a difference that makes, try re-enabling just the most important ones, and possibly reducing their refresh frequency in the process

For Email

• Tap Email
• Tap Menu
• Tap Account settings  
• Tap Email check frequency
• Change this to an hour, or never

For Facebook

• Open the Facebook App
• Tap Menu
• Tap Settings
• Tap Refresh Interval
• Tap the interval you wish to change it to

Turn certain functions off when not in use

Today's phones now have an impressive array of functionality 

• LTE (4G mobile communications standard)
• NFC (Near-field communication)
• GPS
• Wi-Fi
• Bluetooth
• Mobile Data

But do you really need all six activated 24 hours per day?

On your device, swipe down to bring up the notification bar, and then tap the white box icon on the top right corner, select the above functions and turn them off when not in use

Use the power saving mode

Some devices now have Ultra Power Saving and Extreme Power Saving modes, using these modes can squeeze extra hours or even a day of standby time out a small amount remaining battery life

Trim apps running in the background

From Settings > Apps, swipe to the left you'll see a list of apps that are currently running

Tap on each one to see what they're for

You can stop any apps that you don't need running in the background constantly

Remove unnecessary home screen widgets and live wallpaper

Just because they're sitting on the home screen, seemingly inactive, doesn't mean they're not consuming power

You don't need to remove everything as they are part of what makes Android great, just remove the ones you don't use

Turn down the brightness and turn off Automatic Brightness

Screen brightness is a big consumer of battery life, this tip alone will vastly improve battery life

Update your apps

Applications often get updated to use less battery power, so you should make sure your apps are up to date

Even if you configured the phone for automatic updates, some apps still require that you manually install updates

Check for app updates in Google Play by hitting the menu key and going to My Apps

Keep an eye on signal strength

If you're in an area with poor cellular coverage, the phone will work harder to latch onto a strong-enough signal

This has an adverse effect on battery life

There's not much you can do about this one, but keep in mind that this could be the culprit behind a seemingly weak battery

It's worth switching the phone into Airplane mode if you don't need data or voice calls

Buy a battery case or larger extended battery

Battery cases combine a hardware enclosure, which protects your phone, with an extended battery that can double your phone's battery capacity

You can find models compatible with popular Android phones from a variety of manufacturers

Does your battery need replacing?

Over time your battery will begin to gradually lose its effectiveness as it ages. The only option is to replace your battery.