Thanks for sharing those details — the behavior you’re seeing with the 1st gen Apple Pencil isn’t unusual for a battery of its age. These pencils use tiny lithium-ion cells, and after a few years they start showing sudden percentage drops, slow charging, or inconsistent readings like jumping from 9% back to 6%. Unfortunately, once that begins, it usually means the battery is wearing out internally.
Before considering a replacement, try the following things to confirm the issue:
- Leave the Pencil charging continuously for 2–3 hours to see if it stabilizes.
- Make sure it’s seated firmly on the USB-C to Lightning adapter when charging with the 10th-gen iPad.
- Check that the Pencil shows up normally under Settings → Apple Pencil.
If the percentage still fluctuates or charging remains unusually slow, it’s very likely the battery is degraded. Apple doesn’t replace Apple Pencil batteries, so the standard solution is replacing the Pencil itself.