Samsung S6 Edge battery drains quickly even with a new battery

Hi guys, I have a Samsung S6 Edge here, the old battery drains power quickly, got it replaced by a new , still the same, already tried a few different batteries, not much difference. I feel it‘s likely the motherboard issue. In iPhones, it’s usually the Tristar or Tigris IC has problem. In Samsung phones, I am not very sure. I want to ask, on Samsung phones, when dealing with issues like battery draining quickly, it’s usually the big power management ic chip or charging ic that has problem?