Here's an anecdote that's semi-relevant to your question, although the time frames are a bit longer.
I have a c.1995 Compaq Armada laptop that I still use for a very specific piece of software to communicate with a specific piece of hardware(also designed in 1994/1995) that requires an RS-232 port. Due to the nature of the installation, a laptop works best, and the software is also happiest running under Windows 95 or 98.
In any case, this particular beast of a sub-compact laptop actually has the capability of holding three batteries. Several years back-when they were still semi-current-I bought three new Compaq Li-Ion batteries for it. I put two in use immediately, and put the third back.
About a year ago, I tried to carry it around a little while to play some old games, and found that with all three batteries fully charged I was getting less than an hour(about 15-20 minutes per battery). So, I decided to break out the new battery I still had. After 12 years or so of that OEM battery sitting on a shelf, it's completely dead-it won't charge or really do anything.
As I said, that's just an anecdote, but I'd be leary of any older OEM battery.