@user63597 How old is the doorbell and how old is the battery? The battery pack wont last forever, especially outside in the extremes of heat and cold. If its old, maybe 3 or 4 years it might be worth either upgrading or replacing the battery.
My two batteries are approx 1 year old and are rotated , I have the doorbell on what I believe are minimum sttings including no motion detection and on the last 3 change , the latest being today the dueations are 31 days , 26 days and 30 days . I cant believe that these are as intended but could be mistaken.