I've done similar, even with AGM's, when they got real old and were showing "end of life" signs, and I felt I'd gotten enough life out of them to feel ok to swap it out (got my bang for the buck). For what its worth, that AMG brand (AGM) I took out of the 1200 Ducati was still getting the job done, but was cranking slower each start over the course of the summer, then in the cold wx i had the almost-no-start, so i changed it. point is it was a Li-ion, and that one seemed to show similar signs as a lead-acid to being worn out. Not sure what kind of data point that is, but perhaps of interest.