1 Why does my MacBook air power off when battery under 10%
Device MacBook Air (13-inch, Early 2014)
System 10.14.6 (18G87)
A year ago, MacBook Air began to report in the battery bar that the original battery need to repair. The final situation was that the computer was powered off when the battery was low (less than 20%) and the screen cannot been light up. Looks like when the voltage is insufficient, the motherboard will be powered off. Then click the power button again the sign (the red battery warning logo after low battery shutdown) will not show up.
After replacing the third-party battery and resetting the SMC, the battery life has improved, but the low-power instantaneous shutdown threshold has also been reduced to less than 10%, but it has not been resolved. So that I have not seen the notice of less than 5% of battery for several months.
Is this a problem with the power management chip?
Update (09/01/2019)
Most time when I press the power button after MacBook has shutdown automatically, it will restart and shutdown again while the white apple progress bar half.
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Lets get a snapshot of CoconutBattery so we can see what your battery and charging looks like. Take one with the MagSafe connected and a second running on battery. Post them both here so we can see Adding images to an existing question
by Dan