How long does laptop battery last?

if I have a laptop computer how long can be on without plug in

Depends on the laptop... mine lasts 2 hours

it depends on the laptop, or the type of battery.
my computer lasts up to 2 hours, but the battery that holds the charge only lasts 30 minutes.

Yeah mine lasts approx. 2hrs

Depends 6 cell batteries usually last from 1 hour to 2. 12 cells batteries last from 2 to 4 hours.
Depends also on what you doing with your computer and if your computer has good energy management programs.
12 cells batteries are a little more bulkier and more expensive.
I've also seen macbooks have excellent battery life. They go around 3 hours or more.

Depends 6 cell batteries usually last from 1 hour to 2. 12 cells batteries last from 2 to 4 hours.
Depends also on what you doing with your computer and if your computer has good energy management programs.
12 cells batteries are a little more bulkier and more expensive.
I've also seen macbooks have excellent battery life. They go around 3 hours or more.