There are no apps running in the background (I recently factory reset it, no third party apps have been installed except one or two; and I am sure they are not the ones draining battery) and I have tried replacing the battery too; but the drain is 5℅ per hour when the phone is idle. The network signal is strong all time. And the phone has Windows 10 Mobile installed since August 2017, and I never faced such issues earlier. The phone is around 2 years old and the new battery is 3 days old. What could be the reason?