Simply put, batteries don't last forever. Anything more than 5 years old or so is basically a paperweight when compared to a new battery.

Don't tease some newbie by giving it to them, they may think it's good, and their car will be slow and won't run long, so they will think that's how all electrics are.

Take it to a recycling place for disposal.

Older cells are nowhere near the performance of newer stuff, they are only good for comm lathes.... lol