Save power on the cell phone

My HTC S730 is using a lot of power, and has little standby time. Recently it stopped working, so I played with the settings, and by setting the Band Select (“Båndvalg” in Norwegian, and number 3 on the Settings menu) to a fixed value in stead of using the “Auto” option, my phone now uses a lot less power. I selected the “GSM” network type and the “Euro band” band type. My standby time used to be like one to two days, but now its about twice that.