Can my airpods kill the charge case?

I have secondhand airpods and case (not wireless). One day the case suddenly wouldn’t charge anymore, if I plugged it in it might blink red several times but then go blank. If I put the airpods in the case, it wouldn’t blink at all. I have left it to charge overnight, ensured it was clean, no luck. Attempting to do a hard reset did nothing. Went and got another secondhand case today, at first it was working and I could connect to my airpods. Next thing I know, the case is starting to blink red and won’t connect anymore. Now it’s just as dead as my first case. I have tried connecting them to my tablet to reset the FireWall as someone else suggested, no dice. It has had no water damage.

1) Did my airpods kill the cases? I doubt it’s coincidence that both would just happen to die on their own.

2) Is there anyway to restore the cases, even if the airpods themselves are done for?