How to fix Macbook Pro shutdown at battery 30% / 40% left

Last Updated on July 20, 2020

Your Macbook’s random shutdowns might be because your battery is having issues or your battery calibration is wrong if the battery still has some juice left. Did you replace your old MacBook battery with a new one and now your MacBook suddenly shuts down at 30% of battery power or at 40% or 45% of battery still remaining. You are not alone. This is mostly an issue with the SMC or the battery.

Sometimes even though your Macbook’s battery condition is Normal in the battery status. It might not be calibrated correctly.

Even if you haven’t replaced the battery this issue might sometimes occur. Keep reading to find out a solution.

What is an SMC ?

SMC is what remembers your battery full charge capacity and also the lowest capacity, so it can go to sleep or shut down the computer before the battery fully dies.

So when you replace a new battery the full charge capacity will be a lot higher than your old battery so the charge level of your new battery will not be accurate.

What to Do When Your Mac Keeps Shutting Down

Have you just replaced your battery to a new one and is your mac shutting down before it’s full capacity is used. Then you are not alone. Follow the below methods to fix the battery shutting down issue once and for all.

How to do an SMC reset on your MacBook to fix battery shutdown problem

Let’s go through the process step by step to fix the macbook pro shut down due to battery issue.

Step 1: First save all your work and close all applications and Shutdown your MacBook pro.

Step 2: Then remove the charging cable from your MacBook.

Step 3: Now before turning on the mac, Press The Shift + Control + Option (alt) key and also the power button at the same time.

Step 4: Hold those button together for at least 10 seconds.

Step 5: After 10 seconds release all the buttons at the same time.

Step 6: Now start your MacBook by pressing on the power button.


Step 7: Now the SMC will be successfully reset.

After resetting the SMC, you have to recalibrate your new battery to make sure the SMC has the correct full charge capacity of your battery. Charge your battery to full and keep the power cable plugged and keep using your MacBook. Then after a few hours of using the MacBook you can remove the charging cable and let the battery drain until it shuts down. Do this several times to calibrate the battery. This will prevent shutdown of MacBook at 20% or higher once the battery recalibration is done.

Re-calibrate your Macbook Battery to fix Macbook Shutdown issue :

Now you have to re-calibrate your MacBook battery. To do that simply follow the below steps

Step 1: Connect the charger and fully charge your MacBook to 100%

Step 2: After that leave the battery at full charge and leave your MacBook connected to your charger for another 4 hours.

Step 3: Disconnect the MacBook charger and use your laptop to completely drain the battery. Your MacBook will either shut down again at 30%, 40%, or 50%. It might also shut down on a way lower percentage like 10% than previous time like before getting to 20%.

Step 4: Don’t give up now. This is an important step. You have to again connect the charger and charge your MacBook to 100% until there is a green light on your charger.

Step 5: Now disconnect your charger and use your MacBook until it runs out of battery and shuts down or goes to sleep.

Step 6: Now mostly your battery will be calibrated to shut down only at 1% or will go to sleep at a lower battery percentage of 1% or 5%.

Frequently Asked Questions :

How do I fix my MacBook Pro randomly shutting down?

You can fix your shutdown problem by finding what is causing the issue. It’s mostly a MacBook battery problem. You need to calibrate your battery properly or replace your battery to fix the random shutdown during a 40% charge or 30% battery charge. For that, you have to reset the SMC.

How do I know if my MacBook battery needs to be replaced?

On your top menu bar click on the battery icon. If its time to replace your MacBook battery It will show your current battery status mentioned as “Replace Soon” “Replace Now” or “Service Battery”. If you find any of these statuses then it’s better to replace your battery.

Why did my MacBook suddenly shut down?

Your MacBook may shut down due to a battery issue or a MacOS software issue or even a heating issue of the processor. To find the problem Check battery status, check the processor temperature, and if any MacOS error occurs to find what’s causing the shutdown problem.

How to stop my Macbook from shutting down automatically?

Make sure you plug in your charger when your battery is close to 2% or if your macbook shuts down automatically before reaching 5% then try re calibrating your battery.

I hope your battery issue is now fixed and you are able to use your MacBook till the least amount of battery is left. Do share our article with others with a similar issue.

Also do comment below if you have any other MacBook battery issues. We will be glad to help you out. Also, don’t forget to share this post if you found it helpful.

3 comments… add one
  • Yuri Bezerra Sousa Jun 14, 2020 @ 4:58

    Thx. I’ll try it, then I’ll tell you here if worked perfectly

    • Gowthamv Jun 16, 2020 @ 15:46

      Sure. It worked for me. I changed to a new battery and used this method to fix it. It will take at least a few full charging for the battery to calibrate.

    • Oscar Jun 18, 2020 @ 15:29

      Hi. My problem is a little bit different
      I bought the laptop on 2018 and until now the battery only has 11 cycles
      I unplugged it last monday and it powered off at 50% battery
      I followed the instructions but after the SMC reset it powered off, again, at 50%
      I guess it will take a few full cycles for the battery to calibrate
      Does anyone have more tips / information?
      Thanks a lot!!!

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