Here’s Apple’s explanation of what you can expect if you enable the setting:
When you choose 80% Limit, your iPhone will charge up to about 80 percent and then stop charging. If the battery charge level gets down to 75 percent, charging will resume until your battery charge level reaches about 80 percent again.
As we’ve been testing the setting on our review devices, we noticed that our phones have been charging past 80 percent anyway. That’s apparently something you can expect to see…
