True Battery Run Time for G series?

[wesley78]

This form has helped me a lot so far in restoring my g40 thinkpad.

I received this laptop nearly free but it also needed some minor repair.

My current issue is the battery,
I'm only getting 45mins best,
From what I've seen online the g series was horrible with runtime. What kind of improvement should a expect with a new 8.8ah extended life battery? I see mixed results online

Let's say in an average surfing/word doc environment?

I just want to make sure the extra time is worth the battery cost ($90-$120)