The plastic would relax due to heat in the computer and spill the batteries out onto the mother board.
I always used the best available batteries because battery problems were EXTREMELY DANGEROUS in tho days before effective hard disk autodetect.
When people called with no hard disk I'd tell them, "It'll be an easy fix but I need to open up the computer and find the make and model of your hard disk so you have to bring it in, but whatever you do DON'T LET ANYONE RUN NORTON DISK DOCTOR ON IT or your data is history".
Every freak'n time their friend the "computer expert" would tell them I was full of it and just wanted to charge them the big bucks and ran Norton Disk Doctor. Total data loss - every time - the single most destructive utility of all time.
I had guys near tears at losing their life's work. They'd ask about data recovery and I'd tell them, "With the FAT tables creamed, probably about $10,000" (disks were small back then).
Best I could do for them was format the disk and run an Unformat program on it. That recovered some stuff in the early days but didn't work on later machines.
Backups? you're kidding, right? All they had was floppies and you can't expect someone who is completely mystified by what a subdirectory might be (still probably 80%+ of users) to back up effectively to floppies. I do not know why most users simply cannot comprehend a hard disk filing structure but they can't and it's no use getting upset about it. They just can't.