Wow, that was in rough shape! I was actually replacing mine prior to sending the machine elsewhere where it may sit powered off for a couple/few months. SO I wanted to be sure it had a fresh battery in it. Now this... I wonder, if when I slide the control out the front, if maybe the "NC POWER" plug-in terminal got tugged a little too much (it was sitting kinda crooked in it's terminal) and caused this alarm? It's a 24VDC terminal according to the voltmeter. I still have the control on right now for fear of having to recommission it. Which I've done before, but I'm strapped for time right now.
If it's the RAM battery, no matter what I'll have to recommission it, since yanking out the RAM board will lose everything. I don't think I had to do much when I recommissioned it last time, just enter in values supplied by Hardinge, and something with the spindle drive settings (drift?), and backlash comps. But while it's on I can look up those bits and write them down prior to puling RAM card.