Shuts down at around 50% after Battery Replacement
Hi, I replaced the Battery of my iPhone 8 Plus 2 days ago but it shuts down at ~50% even after following the instruction to recalibrate it. When plugging it in after it shut down the percentage shows 13% or 20% but shoots up to around 50% within a minute of charging. The battery health settings as well as coconutBattery show 100% Health. Should I keep calibrating the battery or is the battery defect?
Update: After it shut down I let it sit for around 12 hours to make sure the battery gets as "empty" as possible. This caused the phone to start charging from 1% as intended. However, as seen on the image below, it jumped to 100% within a short time after it reached 50%. I had let it charge for another few hours after it reached "100%", and used the phone as usual after unplugging it. It worked fine and the battery lasted long until it reached 49% like before, resulting in the phone shutting down abruptly. I don't know what to do at this point, should I request a replacement from iFixit? Assuming it's maybe a defect. It's an iFixit Battery by the way.
Update 2: March 16th. iFixit has sent me another battery assuming this one has a defect.
Update 3: March 29th. The new battery has the exact same behaviour unfortunately. After several premature shutdowns, iOS has now applied the Performance management (also known as Throttling). I will leave it enabled for now to see if it somehow manages to calibrate the battery now.
Update 4: April 10th. The problem still has not resolved yet. In fact, iOS now shows a "Service" status in the Battery health settings. Telling me that the "battery's health is significantly degraded" even though the Maximum Capacity shows 99%. Pretty weird, pretty interesting.
Update 5: May 10th. Still no improvement. Still hasn't calibrated. Maximum Capacity reports a value of 56% now. Even though the battery is less than 2 months old.
Final update: June 20th. I contacted iFixit Support once again and they sent me a third battery free of charge. Fortunately this time the battery has no defects or some sort of. No sudden shutdowns etc. One thing I’m not very satisfied with is the capacity of the battery. It has the same capacity as an original Apple battery for the 8 Plus but it feels weaker. If I remember correctly when my 8 Plus was new the fresh apple battery inside it held charges for longer than this new iFixit battery. Though the difference is that back then I was on iOS 11. So that might make a difference, I guess. But anyways, this new battery should allow me to use my 8 Plus for a little bit longer until I finally upgrade to a newer iPhone.
Goodbye and stay healthy.