MBP 2015 battery drops from 50% to 0%?

[peanutismint]

I recently bought a 2015 MBP from a private seller. The battery says it only has 4 cycles which leads me to believe they put a new battery in before selling it (I vaguely remember them saying something about this):

It's been running fine (mostly in clamshell mode/plugged into power) but today while using it portable the battery suddenly dropped from around 50% to 0% and the system shut down, right in the middle of copying a large file from an external USB HDD I might add:

Does anyone know what might have caused this? Is it a known fault? Did the previous seller put a bad battery in? Or is it something to do with me connecting the USB HDD?? It shouldn't happen like this....

 

[Miltz]

There's a high probability that a aftermarket battery was installed that is now failing. There is no other way a battery with 12 cycles that was just put in recently will act this way. Bring it to Apple and have them put a REAL battery in it. Cost is $200.

 

[TechRunner]

My 2015 MBA did the same thing when the battery was bad. Agree with @Miltz here. Time for a new battery.

 

[DMG35]

I believe that is a third party battery installed in your MacBook Pro, and it sounds like its a bad battery. I would take it to an Apple store and ask them if they will put in an OEM battery. Its going to cost you around $200 as said above.

 

[Fishrrman]

Miltz provides "the solution" in reply #2 above...

 

[NewbiePPC]

Should you calibrate your battery?

Should batteries be calibrated? And if so, how is it done? Finally, will this only work for Macs or for iOS devices as well? Let's find out!

thehouseofmoth.com

 

[avz]

Considering that your battery's full charge capacity shows an "overblown" value of almost 10000 mAh, trying to calibrate the battery might be a good idea. When the full charge capacity of your battery will get to a more realistic 7000-8000 mAh, it is possible that it will behave more normal. So in general use your relatively new battery more unplugged and it will naturally "dial in" in a capacity that will produce better operation.

 

[Christopher Kim]

Agree with @avz that I would try to re-calibrate and hope that it's a calibration error. That being said, as others have mentioned, it does sound like it could be a poor aftermarket battery that was installed.

In which case, if you go directly to an Apple store, they'll replace the battery for $199 - and with your model 2015 MBP, it comes with a new topcase, which will include a new keyboard and trackpad. I just did this for my wife's mid-2014 15" MBP which was still on the original battery with 1300+ cycles. Very reasonably priced to get it direct from Apple and breathe new life into the machine.