Some iOS users may experience the rapid battery draining problem of an iOS device. The iPhone/iPad batteries are made up of lithium-ion, hence to increase the service of battery & lifespan these steps to be followed to fix the Battery Drain IOS issue.
The process is known as ‘FULL CHARGING CYCLE ‘
Step 1: Discharge your iPhone until it gets power off ( up to 0%)
Step 2: Once it gets power off then plug it into power source & charge up to 100% without removing the power cable.
Step 3: This will remove all charging errors from your iOS device & Heath of the battery gets restored
Note: Turning on Airplane Mode on your device will help it to charge at a much faster rate as it does not use any antennas for the network.
Apple recommends performing full charging cycle once in a month to get better battery lifespan. IF you are still confused in our given steps then refer the app known as battery doctor which is available free in App Store. To know your battery capacity/how much your battery is able to store the charging/Battery wear level. You can use battery pro app which shows you your device’s battery wear rate.
Just so you know, you are not the only one with battery issues. Take a look at the apple support forum:
Personal Note: If your device is new, and your battery is draining at a very fast rate, don’t run to the Apple store. I had an iPad and after a week of charging/discharging cycle, it works great.