Apple Pencil 1 battery drop to 6 % in 2025 on charging

Apple pencil 1 battery drop to 6% from 37% .is it normal ? and its taking above 1 hour to charge from 6 to 88 percent. And also after reaching 6 percent i unplugged it and on plugging it again showing 9 percent and battery drop to 6 % again please somebody help me ios version 26