Hi had this issue the other day when fixing my sons phone, the phone battery worked perfectly fine with the old screen and when I replaced the cracked screen with a non Apple screen the battery drained significantly faster and in some cases went from 100% to 40 % in mins , the problem I believe is the contact points connecting to the digitalizer on the lesser quality screens , this in turn doesn’t agree with the most likely older Apple battery which are known for there poor performance, in my sons iPhone 5s, the battery had swollen from the replacement of the new digitalizer screen, which in turn was pressing against the new screen, causing the short of the battery, lesson I’ve learned is if the phone is older then replacement of the battery is also needed when the screen is broken, phone works brand new now and it had nothing to do with bits of shielding foam like I was reading on the internet not covering vital parts lol, battery and screen hand in hand if you want to fix this issue and save yourself 3 days of trying to figure it out like me haha