I have an old portable CD player, still works. Runs on 2 AA batteries.
The other day, a CD was skipping, on the third track. I tolerated it for a minute, then forwarded. Other tracks also damaged.
The battery charge indicator read zero. Dead battery or smushy disc? I pop in another CD, works fine. Try the bad CD again, same symptoms repeated.
How does a dodgy disc muck the battery charge sensing circuit?
Sherlock Holmes, paging Detective Holmes, please report to sci.elect.design -