MacBook Air(2015) running macOS Monterey randomly keep shutting off

Run the third party app EtreCheck and post the complete report here so we can examine it for clues.

You can also try running the Apple Diagnostics to see if any hardware issues are detected.

Knightal wrote:

Thanks for the information. I could not run EtreCheck as after a lot of spammy type websites the Apple store said thie app is not available in your location.

EtreCheck is no longer available in the App Store because the app cannot work properly without violating the App Store rules. However, the EtreCheck developer is still part of the Apple developer program so the EtreCheck app is signed & authorized to work on macOS without needing to modify or bypass any macOS security settings.

The Apple Diagnostics gave me the following:-

PPT004

The battery requires a service. The battery is not functioning normally but you may not notice a change in its behaviour or the amount of charge it holds. You can continue to use your battery before it’s checked without harming your computer.

Thats interesting as it was replaced with a new one from Ifixit about 18 months to 2 years ago.

Cycle Count = 131

Condition = Normal

Unless you also ran the Apple Diagnostics immediately after installing the third party battery, then you have no way of knowing whether the diagnostics were ever successful with this battery. Sometimes a third party part will pass the diagnostics, and others will show a failure. I'm not really concerned about the battery if the system failure occurs while using the power adapter.

Without seeing an EtreCheck report there is not anything I can do to assist so you should take your laptop to a repair shop to be examined.