The backup battery protects your data if the main batteries die, and when you change main batteries. However, you have to put it in the right way! The backup battery is located on the right side of your 95LX, behind a removable cover.
There is a top/bottom +/- side to the 3-volt CR2032 coin cell backup battery (available at Radio Shack or other electronics stores). You need to place the battery plus (+) side down in the plastic tray. The HP 95LX User's Guide, page A-4, also says to turn the unit off before replacing the backup battery.
Fred Kaufman
CompuServe ID: [72560,36]