"Charging your iPhone from 90% will not harm your battery either. You simply can't overcharge an iPhone, or any other modern electronic device, for that matter. ... Apple, Samsung and all the top tech companies - almost of whose products use lithium-based batteries - use this best practice.

Is it OK to charge iPhone 11 overnight?

Charge it overnight is fine. You don't have to let the battery drain to 0%. iPhone circuitry and software optimize battery charging. Lithium Ion batteries do not have memory issue.

Does iPhone 11 stop charging at 100?

Question: Q: iPhone does not stop charging at 100%

Answer: A: You can leave it on the charger and it will not charge more than 100%. It will not overcharge.