Ok so I just pulled what I assumed to be an original lithium button cell from a system 3 gottleib board. I wanted to install a holder and replace the cell. I completed the work and wanted to check the voltage for giggles. It tested 3.34 volts yet! 20 yr old cell still good? It looked original, it was soldered in. Still holding memory without a problem, but I hate the unknown. Maybe it had been replaced, but it would’ve had to be done with original replacement parts then. Just blew me away. Wondering if anybody else has had unexpected life results with their batteries.