I have a Macbook Air Early-2015 model since 2017.

Like 4 or 5 months ago, I updated from High Sierra to Mojave. Initially there was no problem. But after a few weeks my Macbook started to shutdown suddenly at about %15 (in changes time to time, sometimes it can be 5%). And when it is closed, I couldn't open it without connecting charge cable.

Because of the quarantine I stuck at home and using it while charger is connected, even it has 100% charge, but not for too long like 1 month or so. But I don't think that's the reason.

Anyway. I controlled battery health with coconutBattery and it was about 80-85%, I can't remember clearly, maybe even more, but I'm sure it was not less. Then I did a research and found SMC & NVRAM reset. I did those resets and calibrate the battery by charging to 100% and draining until it shuts down itself.

The sudden shutdown problem seemed to be solved, but after a few days the Service Recommended warning started to appear. And when I checked with coconutBattery, it said 55% battery health. Still same value with small changes. I mean, how this can be possible? The cycle count is not even close to its limit, it just have 350 cycle. I have friends who has same computer for more than 5 years and more than 800 cycle without changing the battery and their batteries' health are much better than mine.

It seemed like a software problem to me. Before try formatting or downgrading to High Sierra I just wanted to ask you. Thus I won't waste my time by backing up and formatting if it won't make a difference.

Now I have to charge it like every 4-5 hours. And I realized that sometimes the battery percentage is going up. Like, I am looking the percentage and it shows 65% and I am going back to my work, write something in Word etc. 5 minutes later when I check that again, it shows 66%. That's odd.

I don't want to buy a new battery, I can't spend that much money right now.

I apologize for the long text, I just wanted to explain everything :)

Thanks in advance.

  • Batteries have an expected life of 3 to 5 years and yours is at the upper end of that range now. Age is actually more important than cycles. Can you have batteries that last 7 or even 10 years with more than 1000 cycles? Sure, but batteries can also die in 3 years and have only a couple hundred cycles. Theres no "minimum" cycle count that you're guaranteed. Unfortunately, it has to be replaced.
    – Allan
    Nov 23, 2020 at 1:31
  • "I won't waste my time by backing up..." Backing up is never a waste of time. This should be something you do on a regular basis.
    – Allan
    Nov 23, 2020 at 1:42
  • Thanks Allan! I know they have an expected life span but as I mentioned earlier, I have some friends who bought same model before me and still have better health. And maybe you just missed that point: the health was about 80-85% than in about 2 or 3 days it decreased to 55%. No matter how old the battery is, I do not think that such a drop will occur in such a short time. And I backup my important files regularly. However there are files that is not so important but needs to be copied before formatting.
    – Efe
    Nov 23, 2020 at 2:16
  • I linked several answers so that each of your points would be covered. Going from 80-ish to 50-ish percent sounds like a failing cell and there's no way to really test it unless you take it into a proper lab where it can be analyzed - and yes...what you're experiencing can happen without warning. These are chemical reactions (not mechanical) and the SEI layer between the "plates" (anode, cathode, separator, etc. ) and/or cells can build up too quickly due to a defect or failure causing a sudden drop in capacity. How your friends battery performs has no relation to how yours will perform.
    – Allan
    Nov 23, 2020 at 3:29
  • OK, thank you so much for your help. Seems like I'd better start saving money for battery.
    – Efe
    Nov 23, 2020 at 13:54

1 Answer 1


Have you contacted Apple to get a quote on the battery? They can run diagnostics remotely and send a box. It’s worth the time in case they want to service the battery due to a service program at no cost to you. Once they ask for service, it could be a short time till it stops working entirely. Or you could run on wall power at slower speeds until you want to replace or repair it.

  • Yes I got in touch with them and all they said was "We have nothing to do. Batteries' performances can decrease in time even they don't complete their cycles." Yes I know that but it's not an old Macbook, it's just 3 years old. But they did not run any diagnostics. Maybe I should call them again and want a remote diagnostics. Thanks for your answer.
    – Efe
    Nov 23, 2020 at 1:10
  • Yes. Ask them to diagnose the battery and quote a repair. You don’t have to pay once they estimate it.
    – bmike
    Nov 23, 2020 at 1:12

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