I do have a few basic rules I follow on this subject based on many years of experience with PRAM batteries.
Baret's Battery Rules
1. A current PRAM battery should be installed in every machine pressed into everyday use. These batteries should be replaced every six years unless the battery dies before then.
2. No matter the condition, a battery should be removed from any computer in storage, as the duration of storage is often unknown when the computer is put away.
3. If computers are being stored in a basement, they should not be kept within four feet of a furnace. Fluctuations in temperatures caused by furnaces may cause batteries, regardless of age, to leak.
4. Any new acquisition of a used computer over the age of five should have its battery replaced upon receipt unless the battery is guaranteed new.
5. Always have at least one spare battery per three Macs on hand. This is more about being prepared in case of a sudden, non-damaging leak (sometimes discovered when working on computers).
6. If you are able to, solder a battery holder on a logic board which does not have one already (such as a pre-1989 SE or big-box II-series machine).
7. When buying a Color Classic, ask the seller if it has the 4.5V or 3.6V battery. Color Classics were made with two different logic boards, one of which accepts the more common PRAM battery.
I've only had one battery leak, and it was in a computer stored close to a furnace. I wound up scrapping the machine (a Classic) since I had caught the leak too late.
Baret's Battery Rules
1. A current PRAM battery should be installed in every machine pressed into everyday use. These batteries should be replaced every six years unless the battery dies before then.
2. No matter the condition, a battery should be removed from any computer in storage, as the duration of storage is often unknown when the computer is put away.
3. If computers are being stored in a basement, they should not be kept within four feet of a furnace. Fluctuations in temperatures caused by furnaces may cause batteries, regardless of age, to leak.
4. Any new acquisition of a used computer over the age of five should have its battery replaced upon receipt unless the battery is guaranteed new.
5. Always have at least one spare battery per three Macs on hand. This is more about being prepared in case of a sudden, non-damaging leak (sometimes discovered when working on computers).
6. If you are able to, solder a battery holder on a logic board which does not have one already (such as a pre-1989 SE or big-box II-series machine).
7. When buying a Color Classic, ask the seller if it has the 4.5V or 3.6V battery. Color Classics were made with two different logic boards, one of which accepts the more common PRAM battery.
I've only had one battery leak, and it was in a computer stored close to a furnace. I wound up scrapping the machine (a Classic) since I had caught the leak too late.