battery life has become a lot worse after years of good service

I have a Video Doorbell 2. recently the battery life has dropped to less than two weeks.I have two different batteries so i know its not a faulty battery. The wifi is good, there is on average less than 10 events per day and nothing has changed environmentally for ages.What could be the cause of this? I have turned off everything that is supposed to drain the battery ( HDR, light motion frequency)I have run out of ideas!