Laptop Battery Advice

Calling the electronics nerds...
Looking into buying a battery for a friends laptop, but havent had to buy one before (Usually replace my laptops before the battery shows wear lol)

The battery part number is HSTNN-OB31 for a Presario V3000.

This is the one I am looking at on the bay atm:
http://www.ebay.com.au/itm/170726613...84.m1423.l2649

The only question I have is... is it a good battery? How do I tell? There are so many out there i just don't know which one is good. I think the old one is a 6 cell battery so this one being a 12 cell is sure to be better.

Ive had bad experiences with buying mobile phone batteries in the past so im not sure if laptop batteries are any different?

12 mth warranty, twice the battery life

for that price just buy it lol

but yes, laptop battiers are same as phone batteries, can get good and bad without realising it