Macbook shut down but battery is decreassing

This may issue when your Mac's battery reached all its' life.

Before replacing the battery, enter recovery mode and run the diagnostic test. If it does show that your Mac has an issue with the battery, it may be a good idea to replace the battery of your Mac.

You could also check your battery health (maximum capacity, higher is better) in system presences. To check your maximum capacity, press on the "i" button next to "battery health". If it is below 80%, please replace your battery:

For more information about diagnostic test and its results, refer to these link:

1. Use Apple Diagnostics to test your Mac - Apple Support
2. Apple Diagnostics reference codes - Apple Support

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Hello.

It seems like the "auto power" for new M series Mac actually not might be the issue.

I strongly believe that you are talking about the "auto power" function powers the Mac on when the lid is open. The Mac will power on and show the apple logo only when the lid is just open with the chime.

However, the problem that is shown here is that, even though the lid was closed, the Mac has powered on automatically, which was proved when the Mac's lid was open, the user of the Mac was directed shown to a login screen instead of seeing an apple logo with hearing a chime.

So, I think that the only solution is to reset the SMC, or to back up personal data and erase (reinstall) macOS.

If the problem continues, this may be a hardware issue (maybe hardware that detects if the lid is open or not (?)), so please take your Mac to Apple Support for more solutions.

For more information about Apple Coverage, please visit the website below:

Check Your Service and Support Coverage - Apple Support

Thanks

Some M1 machines are close to 3 years old already. Depending on usage and frequency of cycles, it is entirely possible that you already have reached the end of the useful life of the battery. Batteries - Apple covers how the batteries work with more detail.

If you are under AppleCare you might want to see if they will cover it.

Apple Service Programs - Apple Support

offers programs for people out of AppleCare.

Please check out this community forum: MacBook Air M1 Auto Power-On Issue after … - Apple Community

Your Mac does actually shut down, but it automatically turns on again. That's is what all I know, there seems like no solution is found. Please try the solutions above, or bring your Mac to Apple Support

Thanks

Thanks for the specific information.

It seems like there are no problems with your battery, which makes me assume it is a problem related to your Mac's power manager (manages Mac's sleep, shut down, etc).

Please try to hard shut down your Mac (press on the power button for 10 seconds) instead of using the built in shut down option.

Also, try to SMC reset your Mac, and the method is same as the hard shutdown of your Mac.

Wait for a few hours for the results, and tell me the progress.

Thanks

Thanks everyone here for reminding me of the auto-power on feature.

This feature while it makes Macs more like the iPad, it sounds like it could be better designed. Previous Mac models would keep an image of what was running so you could start them up faster. I would definitely bring it up to a service provider and explain to them you want to be able to ensure no battery is wasted when you shut down the Mac, and it only starts use after a deliberate power on. I would also mention, there is no harm in leaving your Mac plugged in while shut down. It will keep it charged. The only reason I would not do that is due to power outages and storms where a power surge could damage the computer.

It seems very strange, because even though Macs don't shut down they have an excellent efficiency on saving power. Could you try reinstalling your macOS with backing u your data?

Sorry, I mean it might be an auto power issue. But except the first line, everything else seems like there is no problem. Sorry again for the accident.