Battery Health

Your micromanagement of the battery charging process is unnecessary and may even be responsible for the accelerated loss of capacity. After 6 months it would be expected to be at 94% or higher, unless you charge more than once a day (which implies very heavy usage of your phone).

The absolute best way to get maximum use on a charge, as well as slow the decline of battery capacity long term is to enable Optimized Battery Charging (Settings/Battery/Battery Health) and charge the device overnight, every night. The battery will fast charge to 80%, then pause. During the nighttime pause the phone will use mains power instead of battery power, allowing the battery to “rest”, and thus reducing the need to charge the battery quite as often. The phone will resume charging to reach 100% when you are ready to use your phone; it will “learn” your usage pattern. If you enable iCloud Backup (Settings/[your name]/iCloud - iCloud Backup) the phone will back up overnight also, assuring that you can never lose more than the current day’s updates. Here's more information→About Optimized Battery Charging on your iPhone - Apple Support

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The short answer is no. Generally speaking, Apple has a number of hardware and software optimizations in place to ensure the battery lasts as long as possible.

If you’re still concerned, you can read more about it here.

Batteries - Maximizing Performance - Apple