If you unplug when fully charged and not use the laptop while the battery is charging, you could get 4-5 hours of use from a full battery. It depends how often you're using the laptop.  Is there a particular reason you want to make it last longer?
assitant
Do you want to extend the charge time?  What else can you do to help?
assistant
I'm trying to make my laptop battery last longer. What can I do?
user
What are your present battery management practices?
assistant
I unplug when fully charged and don't charge the battery until it is below 10 percent.
user
What's the charge time of the battery?
assistant
1 hour
user