3.6V (half AA type) Lithium PRAM/Clock Battery for Mac

Mainland UK only: Sorry for the inconvenience. Due to shipping issues, we do not accept orders for batteries from addresses outside mainland UK.

This small battery is known as the PRAM (Parameter RAM) battery or clock battery. It is used to maintain the state of a small amount of memory which contains certain system settings including the system clock.

The standard symptom of a failed PRAM battery is that your machine's date and time will be incorrect when you boot your Mac - it will generally correct itself shortly after boot when your Mac checks an internet time server. In some Macs you will also see power management related issues if you have a failed PRAM battery.

NB: It is important to install the clock battery the correct way round - make sure you match up the positive and negative markings on the logic board with the battery.