Chosen Solution
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.
At this point your battery looks OK, its reacting as I would expect. Given the fact you have replaced the battery a few times I’m thinking you have a logic board issue within the power rails. Did the system get wet or have a liquid spill? You’ll need to find someone with deeper skills and access to the schematics to figure out what rail is failing. The other option is just replace the logic board.
