If the battery conditioning didn't work, you'll want to try a replacement battery. You have the MacBook Pro (15-inch Glossy) machine. You'll need the battery below:
MacBook Pro 15" Replacement Battery
For the slowness, you'll want to try a couple typical diagnostics. I like to use a utility called SMART utility to find out my hard drive health. If it says "Good" then you'll need to move onto the next steps. If it says "failing," you'll want to make sure you have a good backup of your drive and think about replacing the hard drive in the machine.
If your hard drive says "good," then we'd need to figure out what else could be the issue. I noticed that you're running 1.5 GB of RAM. I typically like to install RAM in even pairs: 1GB by 1GB. I'm doubtful that running unpaired memory could be causing your issue, but it wouldn't hurt to do a memory upgrade in that machine either way.
PC2-5300 1 GB RAM Chip
If you buy two of those, you know you're dealing with good RAM. There is software available that can run more thorough diagnostics of your RAM and your machine in general... Tech Tool Pro comes to mind. But your mileage may vary.
Let us know what you find out so we can be a little more helpful.