Macintosh Pram Battery -

While modern computers have straightforward BIOS batteries, the PRAM battery in vintage Macs was often hidden deep in the analog board or soldered, encouraging a "no user-serviceable parts" ethos. However, the community has kept these machines alive by finding modern replacements, like this Keystone Electronics 108 1/2AA Battery Holder. 4. Exceptions to the Rule

A leaking battery can leak hazardous electrolyte onto the motherboard, potentially destroying the computer. MACINTOSH PRAM BATTERY

Without a working PRAM battery, a vintage Macintosh (like the Plus, SE, or early Power Macs) "forgets" its settings every time it is unplugged. This means losing time, date, and sometimes custom SCSI settings, which can hinder the boot process. a vintage Macintosh (like the Plus

Getting Started With Your Vintage Macintosh – Garrett Fuller and sometimes custom SCSI settings