This is a question, that is hard to answer, because it depends on a lot of different factors such as CPU, Display, GPU. Usually a 15.6" notebook consumes about 20W when using the battery. A 17" unit can also use a bit more.
With these 20W a 60Wh battery would last for 3 hours. t = W/P = 60Wh/20W
The energy stored in the battery can be calculated as follows:
W = U * i* t for a 6-cell battery with 4400 mAh this would be 11.1V * 4.4Ah = 48,4 Wh
With the 20W of power consumption this battery would last about 2.5 hours.
If you wish to conserve battery life, the following tips might help you:
- Use the energy saving function in Windows found in the system controls und the power options
- Reduce the brightness of your screen since it consumes most of the power in a laptop.
- Turn off Wi-Fi or Bluetooth when it is not needed.
- Disconnect external devices like hard drives when not in use.
- Deactivated unnecessary tools or programs, that are running in the background.