Hi,
The problem is that we don't know when your battery would fail anyway. Deciding would usually be done by watching the capacity and then deciding but the decision point is a variable quantity too. I've elderly batteries down to 25% of their capacity and they still work in some things and so I am loath to discard them. Mostly because they can be charged quickly...
So, in your shoes, I'd stick it in the camera and see what happens.
Regards, David