I replaced the battery on my MacBook Pro (Retina, 15-inch, Mid 2014), after over 2200 cycles, with a new one I bought off aliexpress. I made sure to buy the most expensive version, in order to avoid issues, I paid 75$ for a "NOHON" battery with good reviews.

While I was inside I extradited a ton of dust bunnies, with the result of the macbook now being very quite and seemingly faster. It now probably uses less electricity than before.

I checked coconut battery and it says that the battery is in good condition.

However, it seems to me, that the battery is losing a lot of charge very fast. Only minutes after unplugging with 100% the battery is already at 97%. About two hours cost me almost half the battery.

When I bought this notebook, it would basically go almost the whole day without recharge.

Since I know, that there frequently are issues with these replacement batteries, how can I check if the battery has any? Is there anything more I can do apart from checking the health, which only says "good"?

I didn't bother calibrating the battery, because from what I read, unibody batteries don't need that. I did however charge it fully and leave it plugged in for hours after it was charged.

The data I have access to now:

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1 Answer 1


I would run the battery through 3 full cycles and then revisit your data collection. The fact that it works and the firmware on the Mac has accepted the battery and not thrown a “service battery” or fault is a great first step.

Only time will tell if they voltage curve and performance of this battery of cells performs for you.

I would quibble that calibration is needed for all batteries, but that for unibody Macs, that calibration happens as you use the battery over time, not that you have to force it by disconnecting the charger and doing the steps manually. I think it’s still valuable to repeat that old process with any suspect hardware. You won’t know how a system performs in all conditions without exposing it to all conditions. A snapshot of the health when topped off is just a snapshot whether the battery came from Apple’s supply chain and was tested before assembly or DIY like you did quite well from what you report. Great job learning how this all works and asking an excellently documented question.

  • Thanks, Ill give it some more cycles. Now I noticed that it dropped from 40% suddenly to 7%. And max charge displayed in coconut dropped from 8700 to 8500. Strange. Commented May 27, 2021 at 14:58
  • No, that’s what happens when you have second cut cells. The voltage drops more quickly than you expect. It’s not a safety hazard, but Apple gets only the best cells so the less good ones go to aftermarket. It would be strange if yours didn’t have some drop off IMO. You are 100% doing excellent with your scientific approach here, @user1721135
    – bmike
    Commented May 27, 2021 at 17:44
  • As you run it down and up 3 times, those “calculated” and “observed” values will converge in my experience and you will have a stable and repeatable situation.
    – bmike
    Commented May 27, 2021 at 17:45
  • oh, so if it had a ton of bad cells, it would be way down? So the "full capacity charge" being at 8500 instead of 8600 (design capacity) is a good sign? Commented May 27, 2021 at 20:51

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