What if the batteries are worn-out?

"@landanm , @scottdeutsch , Scott D. Deutsch, Some devices do not power on when charging, I am not sure if that is the case for this shaver or not, to answer @landanm inquiry. If you have a Philips Norelco 5801XL find below a guide to battery replacement. This will also give you a chance to look at other components/wires that could be loose/damaged/burnt. I suggest you first try another compatible charger or have charger tested and also if able clean the charge port of any dust/lint carefully with tooth pick or blow out with canned compressed air. Good luck. I hope this helped you out, if so let me know by pressing the helpful button.

Philips Norelco 5801XL Battery Replacement"