As a Static RAM card, the 1 MB card requires a battery to maintain the contents when it is not installed in Newton. Storage cards that use batteries should have their battery life closely monitored and should have their batteries replaced approximately once a year. The Newton hardware warns you if the battery needs replacement. Apple 2MB Flash Storage Card and 4MB Flash Storage Cards use Flash memory technology, which does not need batteries to preserve memory.
Apple originally shipped the 1 MB card with a 3-volt Duracell DL 2325 lithium disk battery. This battery is no longer made by Duracell. The equivlant battery is Panasonic and Rayovac BR-2325.
If possible, leave the 1 MB card inside your Newton to maintain contents when replacing the battery. If you replace the backup battery with outside the Newton, replace the battery in 10 minutes or you may cause data loss.
To replace your storage card's battery, follow these steps:
1) Slide the switch on the top edge of the card into the unlocked position.
2) On the top edge of the card, you'll find a small slot.Using acoin or a fingernail for leverage in the slot, pull the battery carriage out of the card.
3) Place the battery in the carriage slot, making sure the plus (+) side is facing up. Wipe your fingerprints from the surface of the battery.
4) Gently push the carriage back into the slot until you hear a small click.