Battery show wrong percentage
My battery percentage show inaccurate. It show 1% but I still can use another 4 hours no problem and It still show 1%. I charge my phone to 100% than it drop so fast down to 80 60 40 20 than 1 percent but if I turn my phon off than I turn back on it show 90% or more than is drop again. What can I do at this point
iPhone 11, iOS 14