I read in nokia forum a tip to save your Nokia 5300 Mobile Phone battery.
What you need to do is so simple just follow step below.
1- Press "LOCK" after you slide back your Nokia 5300 mobile phone after use.
2-Press and hold your mobile phone red button (end call key) for about 3 sec.
3-Your mobile phone screen will darken and go off very soon, instead of staying on for another 15 sec.
4-Mobile phone screen consume lots of battery juice, and with a gorgeous screen like that, especially one that stays lit for 15 sec after each use, no wonder the mobile phone battery drains so quickly.
Here some comment from user how have try this nokia 5300 mobile phone tip
"Started doing that yesterday, while maintaining my usual amount of calls and messages. I don't use it to listen to music, as i have a great mp4 player for that. (onda vx979, great video playback). Anyway, since yesterday my mobile phone battery shows to be full, second day full. Before it would descend to 2/3 already."
Try it on your mobile phone and tell me if it works for you mobile phone.