Chosen Solution
This might be a strange question but here goes. When I use my Mac, it sometimes just cuts power when the battery is at high percentages like 90 percent. I’ve been able to solve this by calibrating the battery but now I have a new issue. When I get the battery to zero and plug in the charger, my Mac doesn’t wake up like my other Macs where the moment I plug in the charger and log in, all my apps are still open and I can pick up right where I left off. However, this is no longer the case as when I plug in the charger, I am brought to an apple logo screen with a progress bar, indicating that it has restarted instead of resuming like it is supposed to. And all my apps have to reopen themselves compared to other Macs where I am able to resume where I left off. Does anybody know how to fix this. I have a suspicion that it is the battery as dismantling it shows that it is aftermarket and coconut battery reports no serial number. This is a Mac that I have had serviced recently.
New battery with same issue as well
Ouch! This is a bad battery! Basically, the micro controller within the batteries firmware is messed up. This is likely a rebuilt battery taking good cells from one battery and adding in the others from a different battery. Then going into the firmware deleting the information it had which was the S/N, date of manufacture and cycle number (which just restarts counting on its own, now at 4) This is a very cheap battery and won’t work reliably as the cells are already used so its a lifespan will be quite short. Time to get you money back if you can and get a new battery from a good source MacBook Pro 15" Retina (Mid 2015) Battery and do it your self MacBook Pro 15" Retina Display Mid 2015 Battery Replacement
