Battery Life

You can leave your computer plugged in when convenient to do so. Leaving it plugged in will not damage your battery or computer. Leaving it plugged in will reduce the rate of accumulation of battery cycles.

There are many articles for iOS/iPod/iPadOS devices in Apple Support database.

[I've few bookmarked in Mac; for iPhone SE-1 & iOS 13.7.x. +Works best w/ old Macs.]

• About Optimized Battery Charging on your iPhone - Apple Support

https://support.apple.com/en-us/HT210512

"When Optimized Battery Charging is active, a notification on the Lock

screen says when your iPhone will be fully charged. IF you need to have

your iPhone fully charged sooner, 'touch and hold' the notification and

then tap Charge Now."

• Show the battery percentage on your iPhone.

• iPhone Battery and Performance - Apple Support

https://support.apple.com/en-us/HT208387

• If your iPhone or iPad touch won't charge - Apple Support

https://support.apple.com/en-us/HT201569

Don't know. Maybe ask in the iPhone Help Community