Batter backup

Hello,
sir, i want to know that how to extend the battery backup of Nokia 5130, its give to less stand by, and at the talk time its backup is near about 3 hrs only. and sir the main problem is created at the time of listening music because at that time its give on backup of 4 hrs and then switch off. and some it was automaticaaly switched off.
so pls gives solution for all this.