got U2 ic changed the phone works fine but heating and batterydraining

Hi,

Few months back my iphone 5s died(no power up or charging or sync) through google I found out that it might have been because of 3rd party charger that I used while I was travelling.

I got it repaired through a local guy who used U2 IC from another icloud locked phone and got my phone running.

But since then my mobile battery drains in just 8 to 9 hours and my phone also heats up a bit. I tried every way available on the internet to minimize battery drain but nothing works.

I think that my logic board in not supporting that new U2 IC that he used from another phone. Can anyone let me know what might be the issue.

Thanks.