Swollen battery

My original battery is swollen up and unusable. The biggest symptom was not being able to type anything properly with the cursor jumping around all over the place and deleting everything I'd written. Took the battery out and everything is fine.

The question is is there some way of maintaining these things so this won't happen again, or are these just defective batteries? I'm getting a little miffed at the inferiority of our Mac's hardware. I just had to replace the hard drive in my wife's iMac for over $400 and now this. Never had hardware problems like this before with any PC that cost a fraction of what I've spent on my Mac's

I've also read where Snow Leopard may have contributed to this problem. Any truth, or possibility, to that? I bought a 5 copy version of Snow Leopard and was so unimpressed with it that I haven't installed it on the iMac. This is sort of 3 strikes and you're out if Mac doesn't step up and take responsibility for this battery problem.

Not trying to be a troll here, for the most part I love the software, but these hardware problems and Apple's failure to address some of the bugs in Snow Leopard have truly shaken my confidence in the company.