MacBook and battery discharge

Last month, my MacBook (Retina, 12-inch, Early 2015, MacBook8,1) started discharging its battery overnight, even though it was plugged in. (It would recharge after I coaxed it to awaken.)

I reset the System Management Controller and that fixed the problem—for one night. After resetting the SMC, the MacBook behaved normally for the rest of the day and the next day, but the following day (today), it was back to its problematic behavior. I don’t know if it’s significant, but the history did not show the “ramped” discharge that I had seen before. On the other hand, I only have one instance of discharge since resetting the SMC.

(Another peculiarity is that the first of the two above screenshots has the battery at 100% in System Preferences > Battery but the menu bar icon seems to indicate a complete discharge, while the second, taken 2.25 hours later, shows the battery at 1% in System Preferences > Battery and 100% in the menu bar.)

What should I try next? What more detail would be significant? Is it time to retire the MacBook? Thanks.

Option-click the battery icon and see if it says “needs service”. For a 2015 MacBook, I’d be surprised it lasted this long. I had to replace the battery in my 2015 MBA a couple of years ago when it also had a hard time holding a charge and the option click revealed the “needs service”.

A few years ago I had an authorised service agent (in Mosman, NSW) replace the battery% in my 2015 Retina Macbook for about AU$400. It was well worth it.

Although I now have a MBA M2 as my main office computer (with a 32" LG display - replacing a dying 27" iMac) I find the Retina Macbook is still brilliant for travel.

% My understanding is that the Retina Macbook battery is in several pieces distributed through the guts of the laptop. It was a way to keep the exterior dimensions as small as possible.

Update: must have jinxed myself. I just checked my partner’s 2016 Retina Macbook and its battery is only 70%. I am investigating getting it repaired.

I used an App Store app called Battery Monitor to determine the 70% value. The Apple System Preferences/Battery function just told me it needed repair. But it did take me to a relevant Apple web page for organising a repair.

It’s several LiPo pouches glued to the upper case. But replacement is difficult. In order to avoid adhesive solvent from damaging other parts, iFixit recommends removing the motherboard and speakers as a part of the process, which is tricky and time consuming:

I’d definitely consider Apple’s price worthwhile, given the amount of labor involved. Especially when an aftermarket battery by itself costs $110 (167 AUD).

The authorised repairer has just advised “Thank you for supplying the serial number but unfortunately, we can no longer get the batteries for that model MacBook”.

I might investigate aftermarket batteries!

Did you check with Apple directly?


Thank you for the interest and responses.

I assume you mean the battery icon in the menu bar. Clicking or option-clicking has the same effect, and the message is Service Recommended. I first noticed that message years ago, but I use the MacBook almost exclusively with the power adapter. When I do use it on battery, it is almost always for five minutes or less, and that has been fine. Even now, once I get the MacBook aroused from slumber and charged to 100%, it can go five minutes and the battery charge indicator still shows 98% or 99%.

It doesn’t seem to be a battery problem; it seems to be a charging (or discharging) problem. It’s as if the MacBook forgets that it’s connected to the power adapter. Somewhat over half the time, after I open lid, it is disconnecting and reconnecting the power adapter that causes the computer to wake up. (I did swap both the power adapter and the charging cable before resetting the SMC. It made no difference.)

That’s why I bought it, and it worked well for many years. But I am hesitant to invest much time or money on a computer that is stuck at Big Sur.

I agree, if it’s worth replacing the battery, But as I said, the problem does not seem to be with the battery. The battery goes dead (1%) while connected to power and not in use, but charges just fine while connected to power and in use. Does that seem like a new battery would fix the problem?

Yes - the Apple Support website indicates that a 2016 Retina Macbook is repairable but the 2015 model is not (maybe because it exceeds the nominal 7 year limit on replacement parts so it is “obsolete” not “vintage”).

I have booked a repair appointment at the local Apple store tomorrow and am hoping for good news. The estimated price is AU$409.

So my advice is if you have a 12" Retina Macbook that you wish to keep using and have not replaced the battery then consider doing it while replacement batteries are (maybe) still available.

BTW - The iFixit article is for a Macbook Pro not the 12" Retina Macbook but the process is similar, if not more tedious.

Wow - I had my 2015 done just two years ago by Apple. Didn’t realize there was a point where they stopped doing it.


Wow. That’s even more obnoxious than the 15" Pro. And then I ran across this wonderful gotcha:

Definitely not a job I would want to do myself if there was any other possible option.

OP here, with a follow-up. In case it wasn’t clear from the start, the behavior (discharge of the battery while connected to a power adapter) began abruptly about a month ago. After another reset of the SMC, the MacBook behaved normally for a day, then again began discharging the battery overnight, even while connected to the power adapter. About three days later, with no conscious change on my part, the MacBook spontaneously stopped discharging the battery overnight and it has behaved (what I consider to be) normally since. I hope I haven’t jinxed it.

In summary, I don’t know why the problem started and I don’t know why the problem stopped.