I "fixed" the PRAM battery a couple years back when I couldn't find the correct battery with the pigtails. So, I originally ended up soldering replacement leads to a similar rechargeable, but the solder was really way too thick because the solder didn't want to stick to the battery - not even with lots of flux. Even though I filed as much of the excess solder off as I could, it was way too thick and kept the SuperDrive from functioning properly. It was like that a couple years.
The correct battery is a snap. Two quick joints and it works perfectly again... and the SuperDrive came back to life as well as the system settings.
Use this battery - it's well worth the price. Don't be afraid to tear down your (old) laptop. It took an hour or so for the new rechargeable to get up to full power.
The iFixit guides are terrific.