Replacement MacBook Pro Battery Dies at ~70% Battery
I have a 2017 Macbook Pro with the touchbar. My original battery wasn't keeping a charge and it was recommended to replace the battery. I replaced it with an IFixIt battery about 4 months ago. I followed the battery conditioning guide at the end of the instructions and the battery was performing wonderfully until recently.
I decided to finally do the OS Ventura update last week and after doing so the laptop would just shut off without warning with plenty of battery life remaining. Initially it was around 50-60% remaining and now it does it consistently at 70-71% battery remaining indicated in coconutBattery. When I plug the adapter back in, the battery has been fully draining and is charging from 0% indicated by Mac and CoconutBattery.
I've tried the SMC reset a few times without a difference.
It seems highly likely this is was software related issue from the immediate change in battery behavior after upgrading to Ventura after months of proper function, but I tried to remedy that by reformatting and downgrading to Mojave. However, the issue still persists on Mojave with the battery level at ~70% when the shutdown happens.
I cracked open the laptop to check if the battery connections were loose/broken or any abnormality with the battery, but everything looked fine to me. However, now even after a SMC reset coconut battery can't recognize the battery. Maybe the battery is recalibrating since I did disconnect and reconnect the ZIF cable
How likely is it that this is coincidental versus an actual battery issue? I couldn't find anything explaining this behavior anywhere. The closest I got was Ventura was causing excessive battery drainage, but nothing like what I'm experiencing.
Should I try getting a warranty replacement battery from ifixit or does anyone know if this is a software issue that has a fix?
Since last night the laptop doesn't even stay on without the charger plugged in. I've attached a screenshot from coconut. The battery indicator doesn't show on the toolbar anymore either.