iPhone 7 not charging after Tristar replacement

I did a Tristar replacement on iPhone 7 that came in completly dead, drawing 0.00A on charger, no boot, battery dead with 0.02V, the phone had all the symptoms of faulty Tristar IC, before replacing the IC, I checked the battery socket with charger connected in it and it was showing something like 0.14~0.4V, now it's showing 0.40V when charging then I put iPhone 7+ battery inside and the phone booted normaly but it won't charge, so my question is did I do something wrong, should it be charging iPhone 7+ battery or should I order new iPhone 7G battery and then try