iPhone 7 pmic oveheating after battery replacement

i have an iphone 7 that i replaced its battery off of shoppee and an damaged lcd too. but when i added the battery my lcd was not yet ordered so i left it like that with no lcd with the battery on the the iphone 7. a week later my lcd came but my battery that is left out does not charge anymore and stuck on the charging loop. turns out the battery was dead. now i changed my battery finally with the lcd, but now it kept overheating. also i removed each component to see what makes the pmic overheat. after removing the lcd the pmic didnt overheat. but when i used the dead battery on it along with the lcd my pmic wont overheat. is this a battery issue?