Macbook Air Sudden shutdown on full battery after upgrade to Moneterey 12.2.1 OS

Q - I have an older MacBook Air (2014)

Q - Macbook Air Sudden shutdown on full battery after upgrade to Moneterey 12.2.1 OS

A - Sorry but this computer does not Qualify to run Monterey  Computer Qualify for the Monterey upgrade 

Batteries are considered Consumable Products. Over time it will degrade to a point where it needs to be replaced. The usage is normal as the capacity will go up and down all the time and never stay always at 100%. Apple Batteries are rated for 1000 Full Battery Cycles and / or 80% Capacity before needing Evaluation or replacement.

For additional reading on Battery and Apple Computers this link may help. About battery health management in Mac notebooks and especially for the M1 and Big Sur  & Monterey If battery charging is paused or on hold on your Mac

Depending on the Age of the computer, some aspects from the above links, may or may not apply to your computer.

A feature introduced into Big Sur & Monterey was to preserve the number of Full Battery Cycles - there was an Algorithm coded into the macOS. It is perfectly Normal for Big Sur , Monterey to Pause / Suspend charging the battery beyond 80% and hold it at that level. One can nudge / over-ride this by clicking the Battery Icon on Desktop Top Bar and allow charging beyond 80%. From observations, it will Pause / Suspend again once reading 90%. Same procedure to over-ride and will charge to 100%

Q - User Wrote " I have an older MacBook Air (2014)" and "  after upgrade to Moneterey 12.2.1 OS "

A - Even if the Apple Severs had offered the Monterey macOS 12 as an upgrade in error , which it has from time to time. Yes, it does happen.

The Monterey upGrade would have balked / failed or offered an Error Message to the effect - " this version of macOS can not be installed on this computer"

That is, even if it would have allowed the download to occur.

I can only conclude that the MacBook Air is mis-quoted by the OP or the Software upgrade was Not Monterey but possible Big Sur macOS 11 which this computer Does Qualify to run.

Thank you for clearing the Actual and Real Age of this computer .

That said - MBA 2015 to 2022 = 7 year old battery.

Battery does not hold a full charge forever and do degrade over time

Apple Batteries are rated for 1000 Full Battery Cycles and / or 80% Capacity before needing Evaluation or replacement.

That said - MBA 2015 to 2022 = 7 year old battery.

Then the assertions made are without foundation at best.

7 year old battery - have the machine Evaluated at an Apple Authorized Service Provider or a Genius at an Apple Store

The user appears to insist the computer is a MBA from 2014.

In-order to define the actual age of this computer it is suggest to take a Screen Shot as per below ( without the Serial Number Appearing.

This is performed The Age of this computer will Govern what newer version of macOS it will Qualify to install. Use About this Mac from the Apple Icon on Desktop - the required Information will be there.

The image should appear as per below