Test it monthly... at least
Tips from Iridium for keeping your satellite phone in good condition:
· Test your phone monthly.
· Keep the battery charged. For optimal performance, completely discharge before fully charging.
· Ensure SIM card is locked in place. Remove the battery to check if the tray is securely positioned and locked.
· Protect the phone’s antenna. Stow the antenna in the “down position” when not in use.
· Call outside with a clear view. Avoid obstructions to the sky and the horizon such as buildings and trees.