I've a dozen group 24 AGM batteries pulled from one of my UPSs as "approaching end of life" (easier to pull them while they aren't complaining than to wait until they sh*t the bed at some inappropriate time!)
I'm debating idling that UPS, for a while. So, the logical thing to do is just recycle the old batteries and bank the "core charges" for the day when I need to replace them in the future.
*But*, I can also tinker with them to see if there's any practical way of extending their useful life! [lots of youtube videos and the like but I suspect many of those folks are *just* tinkering and not really expecting any savings from their efforts (no one ever follows up to indicate how long the battery's service was extended nor how its capacity was affected)]Of course, that means finding a place to store them (or, reinstall in UPS) instead of enjoying a bit less clutter! :-/
So, anyone with first-hand experience on these larger units?