89% Battery capacity 113 cycles since May 20

That computer is battery-CAPABLE device. It is not optimized as a battery-operated device.

Your computer performs best when connected to AC power. It can use the full output of the Power Adapter AND when doing especially challenging work will also freely "borrow" power from the battery. In some cases, the charged state may even decline during stressful work.

When used only on battery, your computer has no extra cushion of power, and will perform more slowly. However, for ordinary non-stressful tasks this may not be objectionable (possibly not even noticeable.)

In general, you should ALWAYS connect AC power when it is possible to do so, and only run on batteries (which will be somewhat slower) when no AC sources are at hand. There are three micro-controllers cooperating on battery and charging issues, and your Mac will NEVER over-charge.

An external power supply that provides "USB Power Delivery" (like certain displays) can not 'force itself' on your Mac. The Voltage and Current are delivered only after your Mac requests and the charger agrees to supply power under certain controlled conditions. The computer is in control of the entire process.

A charge cycle is ever-so-slightly destructive to batter longevity. When operating as designed (and not using Battery Health Management) battery charge level is allowed to decline to about 92 percent level before initiating a recharge cycle to top up to about 99 percent.

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Catalina software 10.15.5 for MacBook Pro with T2 chip (2016 models and later) includes a new feature called Battery Health Management. Based on your usage patterns, this widens the hysteresis to initiate a charge cycle at a lower level, and stop before 99 percent.

About battery health management in Mac notebooks - Apple Support

https://support.apple.com/en-us/HT211094

This relaxes the set points around re-charging (based on your usage patterns) and can improve long term battery lifetimes. When active, recharging may stop short of 100 percent charged.

That's normal. The decline is not linear, the battery generally drops to ~90% health over the first 100-200 cycles then stays there for a long time. My 2017 15" MBP has over 300 cycles and is at 91% health. My 2010 17" MBP has close to 800 cycles and is at 88% health.

SeriesX5 wrote:

The decline is expected? I genuinely feel something is wrong with mine. Another full charge the max capacity dropped from 4559 to 4545

If you think you have an issue:

You can always Try resetting the SMC https://support.apple.com/en-us/HT201295

Apple Support on line https://getsupport.apple.com/

Call Customer Support (800) MY–APPLE (800–692–7753)

or call AppleCare Support at 1-800-APLCARE (800-275-2273)

the new normal—

macOS Catalina 10.15.5 introduces battery health management, a feature designed to improve the lifespan of your Mac notebook's battery.

The Battery Health button appears in >SystemPreferences>Energy Saver —this feature is limited to Mac laptops with Thunderbolt 3 ports. That equates to all MacBook Pro models released since late 2016 and the Retina-capable MacBook Air models released since 2018.

About battery health management in Mac notebooks https://support.apple.com/en-us/HT211094

If you were to disable the new feature, it would go back to the old way of what you are expecting to see.

It’s normal. You can call Apple, they’ll tell you anything >80% is healthy. I recommend just plugging in when you can, running on battery when you need to, and not obsessing over it.