I would say it was from a PMG's Dept/Telecom Aust installation.
Oh I know where they were from, I retrieved them myself. A very soon to be demolished installation.
It was coms-related. And I think I do have pics of the installation, just haven't found them yet. Was years ago.
Also sadly it seemed that all service docs had been removed/destroyed already.
... you might want to consider getting some phosphoric acid for your old cells and give them some love like outlined here:
https://www.instructables.com/id/Lead-Acid-Battery-Care-and-How-to-Restore-Them/
I have doubts about the worth of that article. Zero mention of sulfation as a factor in Lead-acid battery demise (and the major cause of plate swelling.) Also his talk of adding phosphoric acid... hmm, if that was such a great idea for battery improvement, why isn't it done by battery manufacturers as standard?
Also his spelling and grammar sucks, which isn't inspiring either.
That he specifies phosphoric acid additions in ml, rather than moles for some other concentration-adaptive units, suggests he's a bit naive.
Plus, if he's such an expert on lead acid cells, how does he not mention other common types of cell-death, such as plate disintegration, fracturing of cell interconnects, etc? See
http://everist.org/NobLog/20180430_lead_acid_ruin.htmHas anyone else actually tried the phosphoric acid treatment, and what were the effects?
I'm NOT going to do something like that to 15 seemingly good 300AH cells, just on advice of one dodgy article.
It's something to research some more.