I've a shitload of UPSs -- most in the office.
>
> Power *tends* to be pretty reliable, here, so they aren't
> used for their "backup" capability. However, we do tend to
> see "switching transients", predictably, at certain times
> of the day. So, having a "second" of carryover is often
> helpful (on the smaller machines; the larger ones have big
> enough power supplies that they can bridge these momentary
> outages)
>
> Instead, they tend to be "outlet multipliers" in much the
> same way as outlet strips might be (though a better form
> factor, given the layout of my kit). They let me connect
> all of the devices for a host to the UPS associated with that
> host. Then, power them all on/off at the same time.
>
> But, most importantly, it lets me get a feel for how much
> of a load I have on the mains -- so I don't carelessly
> add some new load that blows a breaker!
>
> Replacing batteries is a costly -- and time consuming -- exercise.
> A single "shared" battery would be the preferred solution. But,
> not possible with COTS UPSs (nor the associated IR drops).
>
> OTOH, I *could* plug more than one UPS into a single (or few)
> "master" UPS that effectively takes on the role of the mains
> connection. Then, I just have to keep that/those UPS running
> ("properly") to gain the benefits of bridging those brief glitches. >
> Any downsides to this? If I remove the batteries from the
> "slave" UPSs (i.e., don't replace them when they fail), then
> I can avoid that maintenance issue but still retain the other
> advantages of the UPS-per-workstation.
>
> Or, maybe put some trivial "power source" in their place that
> is just enough to satisfy the UPSs' expectations of a "battery"? >
> [I'd still have to put up with the "connect battery" messages
> but maybe I'll hack the firmware to "fix" that issue -- and,
> stop the silly scrolling of "screens" so I can just see the
> data of interest, constantly.]
>
> [[UPS manufacturers seem to have s***ty/buggy/unfriendly software]] >
Some UPS designs cannot be turned on[*] without a battery in them, even when supplied with mains power, because they cannot energise the relay that enables the mains connection.
Sylvia.
[*] They can stay on, just not be turned on.