Hot work on UPS equipment

[Aleman]

It may possibly be considered safe from electric shock hazards, it may still present arc flash hazards.

You are right on that one. But I do think that touch safe panel construction would reduce the possibility of an accidental flash, like getting across
terminals or shorting something out.

 

[Electric-Light]

Interesting fact: Hybrid and EV batteries can have enough fault current to be classified as category IV.

 

[wtucker]

The OP asked about the UPS, and in almost all cases, you can disconnect the batteries from the UPS.

Not to put too fine a point on it, the OP asked about "UPS equipment," which I took to mean the whole thing, batteries and all. A colleague of mine who works for a company that makes and installs UPS systems once told me he worries about guys who work every day on AC, then are called upon to work on DC and aren't qualified.