Remove the battery cover from the slot on the top of the handset.
To remove the battery, lift from the notch on the bottom of the battery.
Clean any debris off the gold contacts on both the battery and the handset.
Note: To clean the contacts it is recommended to use a soft cloth.
To re-insert the battery, place the top of the battery in the compartment, ensuring the gold contacts align with the terminals at the top of the battery compartment, and then press the bottom of the battery into place.
Reattach the battery cover.