Apple eMac PRAM Battery Replacement
How to replace the PRAM battery in an Apple eMac computer. It is really a simple project. The most common sign of a dead PRAM battery is when you find that whenever you unplug or lose power to your computer, you need to reset the date and time. The PRAM battery allows the storage of date, time and other settings in your computer. PC computers call their battery a CMOS battery.
I bought the battery off of Amazon for $4.99 and it was 1 day shipping. You'll need a 3.6V 1/2 AA lithium non-rechargeable battery.
This video features an Apple eMac G4/800 computer made in 2003.