My 6s also drain battery much faster like 0% health battery. 12.30am there was 68% battery capacity. So i turn on the battery sever an set alam to wake me up 6.30pm. Today morning at 6.30am my mobile battery was 1%. Why is that? I didn’t do anything. 68% to 1% with in 6 hours without doing anything. This experience happens after update my os 13 to 14.3. Please help not i updated it to 14.4 also. I hope apple will fix this issue soon. My battery health 85% i was planning to get apple 11 pro but now I’m afraid to buy that because if apple treat to old devices like this. One day new devices will get the same issues soon.