I have my laptop ( Dell Inspiron 14R) on dual boot with Ubuntu 12.04 and Windows 7. While using Windows 7, I used to get about 2.5-3 hours on battery fully charged (with my cellphone connected for 3g Internet). The battery is almost 2 years old. But in Ubuntu 12.04, I'm getting only about 1-1.5 hrs on battery.

I tried installing jupiter, also tried some tweaks that were mentioned in the forums, like editing the grub file. But nothing seems to work. I am not sure if any app is draining the battery. The one application that I use always is firefox. It's always open.

Is there any way I could get at least 2.5 hrs of battery time?