I have the same problem. About battery draining.

I have the same problem to. I used iphone X and my wife also use iphone X my battery health was 84 percent my wife's battery health was 82 percent. we had changed our iphone batteries to new one. after we installed it , and update the software. we got the same problem every day our iphone X, drained to 10 percent by the software displayed. after we restart it, the battery become the real data, for ex: around 80%. after we leave it for several hours with standby, the iphone suddently error and need more restart. It happends 3 times a day. i have to keep restart my iphone 3 times a day. and sometimes, when i use the iphone, the mobile suddently shutdown by it selfs. so sad about this ios 14.2. hopely new 14.3 get better. because i'm an apple fans. APPLE, Please help me. best regard.