Definition: Given an Amazon customer review, write a title for the review. The preferred titles are under fifteen words.
Input: I use this for my Thinkpad W530. I didn't realize how much I needed a replacement 9-cell battery until I started using it. It's something about being able to use it for 8 hours at a time and not having to worry about charging that makes me excited.

Solid 7-9 hours of power