I'm in the early planning phases of a mod, and one of the ideas I've been thinking about is building a UPS into the case. I'd be using a V2000 and leaving the middle bulkhead intact, so the parts in the lower compartment would be the UPS, the PSU, a power brick for my Wii (which is going into a CD drive bay), a stand-alone TV tuner to make the Wii output in VGA, the hard drives (in metal boxes), and possibly the pump. The 120 volt parts in the case will be the UPS itself, a pair of power bricks (one for the Wii, one for the TV tuner), the PSU, and power cables. Will this be OK? I'm not planning on having any windows in the lower part of the case, so if I need to, I can build in more EMI shielding.
In simple terms the UPS is a big battery and a switch... We have rack mounted UPS's underneath servers (1/2cm away from components) and everythings fine.
Now that's what I call an all-in-one mod! :O Can't wait to see the actual modding process for this mod dude, hope you can work all this out.
Um... No? There's a lot of stuff inside a UPS. There's a battery (as you said), but there's also an inverter, a transformer (some have a big gransformer, some don't), and a bunch of monitoring electronics. By volume, your common desktop UPS is only half battery.
That is going to be a very very heavy case - hope you aren't planning to take it to any lanparties...... (Keep in mind - ups batteries have to be replaced eventually....)
Actually, I am planning to go to some. They're usually at my house (I own the network hardware we use), so all I'll need to do is move the beast downstairs. And yes, I expect the thing to weigh a ton. I'm considering extra bracing and wheelsets to hold the weight. But did weight stop Franklin and his AlumaxX? Did it stop G-gnome (the great) and WMD? I've got a crazy idea, and I'm not going to let little things like, say, a broken back stop me. (And thanks for the heads up about the UPS battery. I'll have to make it easy to get at.) What I'd really like is a UPS-PSU combo, where the UPS puts out DC to the PSU, so it doesn't have to run through an extra inverter and transformer. Haven't seen any of those, though, and I don't really feel like trying to do it myself.
My UPS (APC XS1000) had to be separated from my old CRT or else it caused interference on the screen. The part I'd expect to see trouble from is the TV tuner (though I'm no electronics expert). At the very least I'd recommend shielding the UPS.
The trouble is, it isn't the simple bits that I'm worried about causing EMI. I'm much more worried about EMI off the inverter than off the DC side. Out of curiosity, are your rackmount UPSes outside your (presumably steel) server cases? A steel case makes at least a decent Faraday cage. I'm wondering if I'm going to need to build similar protection for my stuff.
Just to clarify - a battery on a NEW UPS should be good for about 2 years - give or take..... So, don't spend too much energy making it easy to get to - just make it possible.
Could it be that the UPS included some magnetic resonant power stabilization? Those units have a lot of stray field when they get old. Did you consider a battery with a low voltage ATX supply like http://www.zantech.com.au/synocean/stc048400.html (if link goes dead try http://www.google.com/search?hl=en&q=48V+atx)? You can run it from two truck batteries, which you can charge from a wall wart, a solar panel, a windmill, your exercise bike or whatever makes >55VDC. That solution is more expensive, but absolutely free of transfer glitches when the UPS switches from line to battery.
2 years or 2 ten minute power outages. The dirty little secret of UPSes is that they run the batteries WAY over their rated limits, essentially destroying them in the process of saving your data (they can draw ~100A from a 7 Ah gell-cell). Once they're used once it significantly reduces the batteries capabilities, twice and there isn't much left. The short transient outages aren't much of an issue (the ones that just make the UPS chirp for a second or two). It's the outages where you actually wind up having to shut down your computer on UPS power and wait for the power to come back on.
everything should be as simple as possible, and no simpler. Oh, and wolfe, what UPS's have you seen that try and pull 100A from a 7Ah SLA? That just sounds like poor design. Not saying its not true, as it certainly sounds like something a cheap 900+VA ups would try and do.
Pretty much every small desktop UPS. Look at it this way. A computer generally draws ~200-400w A CRT monitor draws ~ 150-300W (depending on size) So, go for the average: That's 550w for the generic computer. Power = Volts * Amps (roughly), so 550/12 = 45a, plus 80% converter efficency = 57a (and that converter efficency is probably overrated) It's not quite 100a (which was a number off the top of my head), but it'll still totally trash the gell-cell. Incidentally, it's also of note that the UPS pays no heed to keeping the battery between proper charge and discharge limits. UPSes are designed to run the battery into the ground to squeeze out every second of computer life. It's not necessarily bad design, it's just a system that isn't designed for longevity. A UPS designed to handle a battery of a size appropriate for repetetive power loss would be enormous and expensive (and heavy!). It's more profitable to sell cute little UPSes, which your average customer can actually lift.
Since I never felt the need to open it up I have no idea what all is inside. It was brand new at the time but moving it one foot farther away fixed the problem.
Both the UPS and the server are in steel cases, but thats just how things come. If your worried just build it in a seperate compartment, its not like UPS's have pretty insides anyway so not worth looking at.
