If you're looking to fix My Iphone Won't Charge (https://techzeel.net/iphone-wont-charge/) issue then below are the steps to Disable Optimized Battery Charging:-
1. Launch Settings on your iPhone.
2. Scroll down, and tap on Battery.
3. Next, tap Battery Health & Charging.
4. Find and turn off (or toggle off) Optimized Battery Charging.
5. Lastly, confirm your action by tapping Turn Off on the pop-up dialog.