MacBook shut down at 20% battery with no warning? [duplicate]

Solution 1:

I had the same problem with a MacBook Pro mid-2009. Even changing the battery for a "non-official" battery did not solve the problem; I had to take it to an authorised Apple service centre; after that, no problems and still happy as the writing of this (about two years).

Any workaround that you might find online (resetting SMC and/or PRAM, recalibrating, etc) is just a temporary measure, they won't hurt at all and might give you some peace of mind.

Besides changing the battery for a new one, the Apple tech guys have special "secret" programs that can modify certain system flags and parameters.

About a year ago my MacBook Pro Retina mid-2012 (2.7 Quad i7) started with the same exact problem; the shocking news came with an estimate of $975.00 AUD to replace the battery (as it comes glued firmly to the housing you have to replace the unibody bottom including keyboard and trackpad). Still one year later the battery has not degraded at all and I still get 3-4 hours of battery life with full performance settings, but now the message has changed from "Service Battery" to "Replace soon", after this there is still a "Replace now" message.

In brief:

Service Battery means: There might be something wrong with your battery, or it could be nothing, but keep an eye on it.

Replace soon means: Your battery will last less than expected, but there should be no major issues, stay alert.

Replace now means: If you hate carrying around your charger have your battery (or the entire laptop) replaced.

Hope this helps.

Solution 2:

Once in a while (like 3 months or more) you should recalibrate the batter charge percentage. The reason is each time it charges it uses the previous value as basis (and it is a assumption that one was correct) so the error accumulates.

So once in about 3-6 months, you should let your computer shut down because of a´batter warning. Now you did that it it should be behaving better now.

It is not recommended to do the discharge to often (the battery does not like that.)

Solution 3:

I have the same problem on MacBook Pro Retina, early 2013, OSX 10.10.5 Yosemite. Shutting down without warning around 22%. In the battery menu it says "Service the battery". The reset of the SMC didn't help. Yesterday I asked at Genius Bar about this. The answer was "We need to investigate it and probably you will have to replace the battery." It is not free and they need to keep my computer for few days, not good option for me. After the visit at Apple I tried to drain the battery totally by restarting several times after it shut down. And it was shutting down again and again quite quickly, the charge indication was changing a bit irregularly, sometimes 17% then up to 19% then lower again. I left it for the night, restarted in the morning and it worked normally. The battery went down from around 18% to 2% and went to sleep normally. There was no more message about the Battery Service. Now plugged and charging, around 20% I have the "Service battery" message again. I do not find any fix for it.