Not many people complained Nokia 5800 battery performance, because it already has great battery life! However you can still do some tips to make the battery life longer. Tzer2 wrote a great tutorial to maximize Nokia 5800 battery life at AAS site. Here some to do list that you can do:

- Fully charge the phone’s battery
- Do NOT switch the phone off!
- Shut down unnecessary applications
- Turn down the 5800’s screen brightness to the lowest acceptable level
- Switch off your 5800’s screen when not in use
- Use headphones instead of speakers
- Avoid using the camera flash unnecessarily
- Use 2G instead of 3G
- Try to get a good signal
- Use Offline Mode (aka Flight Mode)
- Switch off Bluetooth and/or Wi-Fi

Some of the tips might be an obvious point, but it’s a very important. And if you think “Do NOT switch the phone off!” tips is sounds crazy!