Smart-UPS RT 3000VA 208V 3U Rackmount UPS System

This UPS occupies an unusual spot in the marketplace. It's a 208V/240V (single-phase) rack-mount unit, higher-end than any of APC's extensive line of "oh, we really ought to have some kind of backup power for this server" units, but it has no place in a "real" datacenter where the UPS equipment is the size of a Volvo and nowhere near the rack.As a result, there probably aren't that many places where this can actually be used. I believe there is also a 120V version, which is probably a lot more useful to most people.But you have to love APC... despite the rarity of uses for it, they made this thing anyway.We're using this one to power a "replica rack" in our R&D facility that matches our datacenter, where everything is 208V. The first great thing about it is that it let us put in a simple 220V/240V circuit and it handles stepping that down to squeaky clean 208V single-phase for the equipment (by way of a matching 208V PDU).This unit is designed to be maximally-serviceable in operation. Batteries (included) and the network management card (not included) can be serviced or replaced without taking the unit down. Which, you don't ever want to take a multi-KW unit (and all the equipment it's running) offline. The only thing we're not sure about is whether we can service the batteries (one by one of course) *while* it's on battery power. It seems possible, but somewhat unlikely.If there is a star-subtracting drawback to this, it's the battery runtime. On its own, its primary function is to provide clean power; the fact that it also keeps working for a few minutes during an outage or brownout is more of a bonus. For serious runtime, additional battery packs are required. Which is an option, but it's not a trivial one. Each one is another 225lbs. A full stack of 10 battery packs will provide 8.5 hours of runtime at full load. It will also weigh almost 2400 lbs and take up 33U of rack space. That's not very realistic; not that many floors can even handle live loads pushing 500lbs/sqft. So, more realistically, with either zero or one battery pack, most appropriately-sized loads will have 15 minutes to 2 hours of runtime.APC is a solid company and they offer a two-year warranty on this product. Having used that warranty (the first unit we received was DOA), they definitely stand behind their products.All in all, if you need something like this, this is what to get. We wouldn't dare use anything else.