BleepingComputer.com: Need new Battery

I need to buy a new battery for my laptop and after browsing tons of websites I'm still kind of unsure what kind I need, I've never had to buy any new hardware before. I have a Compaq 6735s. Is there one specific type of battery that goes with this laptop? If some one could just help me figure out what battery I need to get and point me to a good site to buy from I'd really appreciate it.

Also, and I realize this question probably should be posted on a different forum and I can do that if need be, but I thought I'd just try to kill two birds with oen stone. This laptop I'm using isn't even a year old. I got it as a gift in January and now I can't leave it unplugged more than a few minutes without it shutting down. I know a laptop battery isn't supposed to die that quick. Is there anything I can do to make sure this doesn't happen again with my new battery?

Here is what one looks like.

http://cgi.ebay.com/Battery-For-HP-COMPAQ-...=item45ee87f6ed

You should have the part number on your existing battery.

DR