Sudden Battery Failure While in Sleep Mode
10 - 45 minuten
Slept the MBPro, got up in the morning and the sleep light was off. Pushing the battery charge button on the left side produced a rapid and very odd fast couple of flashes I'ld never seen before from 2 of the LEDs on the left side battery indicator. I knew the battery with 450 cycles was dead.
Once I got the iFixit battery, changing the battery out was easy & routine. But, you NEED the tri-lobe screwdriver, which I didn't see listed on the iFixit site as I was probably in a rush.
The question was what would happen on boot up? Battery indicator lights initially on the new battery showed charging was not accepted from the charger brick which was odd, but understandable after the MBPro shut itself off with the original battery failure in sleep mode.
The question was what would happen on boot up? Battery indicator lights indicated 70%; plugged in charger and hit the power key.
An odd sequence then occurred as if the MacBook Pro went into a deep hibernation, but didn't power off when the original battery suddenly 'went off.' It also was apparently not upset during the battery replacement apparently. I wasn't prepared to document exactly what happened, but hitting the Power On key did not cause the MBPro to go through the cold boot routine, but just resumed as if coming out of hibernation.
Once up and running & then restarting once and, everything was back to normal.
Given the MBPro is 5 years old and used every day, I think it is time to buy a used MBPro as a backup as I don't want to upgrade until the Skylake MBPros hit with Thunderbolt 3.
I really can't say how to handle a MacBook Pro properly when the battery instantly fails while in sleep mode and then won't come out of sleep with the charger plugged in, no doubt as a safety procedure.
This type of battery failure seems to have triggered a safety mode within the MBpro and it would not wake even with charger power so it could be properly shut down prior to the battery replacement.
I don't know if there is potential for corruption in this mode, but would like to know. Apple must have some notes on this to help other people.