Is this a dead clock battery? I opened the VMU to see what it took, but I'm worried the little cylinder below where the speaker cables attach to the PCB is what I'd need to replace. I have NO idea what to even look for, as replacements go. Does anyone have any experience with this issue?

What I've Tried:
-New batteries
-Wiping down battery contacts
-Tightening screws
I'd appreciate any help!