If it’s lead, (1) they’re fried from low voltage, most likely, and (2) you’re not going to hurt anything trying to charge them back up and see if they hold anything useful.
(3): You’re aware of DC arc fault hazards, right? A 240VDC pack is firmly an arc fault hazard, do not disconnect under load.
Yes I have a proper fear of DC + high current capable source, I haven’t felt the courage to even open up one of the battery modules yet. I’m hoping maybe its a bunch of smaller modules series connected and it would be easy to break apart into individual lower voltage batteries…
I also don’t have a voltage supply at home that could charge them, I was hoping to get the UPS to power on and charge them itself. My biggest DC supply I have at home is 50v.
Well there you go then. I thought you were talking about a standard Tripp-Lite UPS like you get down at <insert random big box office store>.
I would bet good money it’s about 20 small 12V sealed batteries in series.
I can’t find an amp-hour rating on the expansion modules, but I’d wager it’s in the 7-9Ah range, so around 2kWh. Give or take.
If the whole pack is at 150V, it’s discharged enough that there’s not enough energy to do much. I mean, don’t short across terminals 15 batteries apart, but it’s fully discharged.
Winner! ALthough these ones are only 5 AH, its the smaller pack, I wonder if the 2 other bigger packs are made out of slightly higher capacity 12volt packs.
is there any way to resuscitate or test these things. maybe make them into a mega parallel 12v pack somehow?
The larger packs are probably the same thing with 7Ah or 9Ah batteries.
Pull a few and look at the voltage on them, but I’d bet they’re low, uneven, and mostly toast. At least they’re not swollen, that’s always fun (trying to remove swollen batteries from a UPS when they no longer fit through the opening on the side).
In general, if they’ve been drained <12V for a long period, they’ll be scrap, though, since you’ve got 'em, no harm in dorking about and maybe finding a desulfator program for some charger or another. I wouldn’t hope for much, though.
Also, those tend to be designed for standby use at float charge - they wear out quickly with daily cycling. So not really good for much beyond UPS duty.
Could I wire them all in parallel and make a mega-UPS with 10x the capacity?
I could almost make a desulphator with parts from the dead UPS. Will it really work magic beyond what charging them at a constant voltage would do?
I should probably not waste time on this, but there’s so many batteries.
edit:
hmmm, this guy also got his batteries from a dead UPS
http://everist.org/NobLog/20180430_lead_acid_ruin.htm
Are we talking about wiring the batteries to power the smaller consumer 12/24 volt UPS’s? I don’t think those inverters are typically rated for 100% duty cycles with battery capacities far beyond what they were designed with with.
I could be wrong but I suspect it would be more reliable and more efficient (electrically speaking) to get even a cheap modified-sine-wave inverter and run that with a charger. It’s just forgoing the auto-switching from grid to battery part of the UPS.
Yeah, I jumped to the small UPS idea because I have one with a dead 12 volt battery. BTW the 2 batteries I charged are still over 12 volts after sitting overnight. No need for a desulphator zapper thingy yet.
I just charged them with ~14v, they were drawing about 0.25 - 0.5 amps.
there has to be SOMETHING cool to do with a massive pile of batteries 
You could, but would ruin the batteries in very, very short order. Lead acid just doesn’t like being paralleled, and doesn’t tolerate it very well at all. You end up with one string (and a single battery is a string of cells, so counts) taking a hair more current, getting warmer, and positive feedback loop overcharging while another string, colder, doesn’t take the current and undercharges. With really good condition batteries and careful wiring, you can usually get away with two strings in parallel, three is iffy, and beyond that, you’ve just built a battery murdering device.
A desulfator probably won’t work, but if you have one around, may try it. The problem, as so well noted in your link, is that they do nothing about the various physical destruction mechanisms of battery degradation. You can perhaps drive off some of the hard sulfation crystals with one, but it doesn’t help with positive plate corrosion (which I believe is the dominant failure method in sealed/AGM type batteries), active material shedding (more of an issue in flooded), etc. And no amount of magic powders or patented zapping patterns will solve the problem of “Your active material is no longer connected to the grids.”
Careful there… a bad idea, scaled up, does not magically become a good idea.
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Test a couple of them if you must (beyond just holding voltage, you should load test them and see how many amp-hours they actually retain, and I bet it’s very few). But they’re float service batteries, worn out, and so even if they do hold a charge, they won’t for very long in regular cycling. That’s not what they’re built for.
In general, with lead acid (as with other battery types), you can trade off between weight/size, power (peak kW), energy storage (kWh), cycle life, etc - and you can’t have everything.
Deep cycle batteries, like the ones in my office (Trojan T105REs) tend big, heavy, with thick plates and extra acid capacity. They can handle deep discharges as long as they don’t freeze, they have a quite long cycle life (I’m hoping to get 10 years out of my bank in daily cycling use), are quite heavy, and won’t source that many amps before sagging (especially in the cold). Mine are flooded, so I can beat the hell out of them on the charging side and as long as I water them a couple times a year, they’re fine with it. I charge at 2.47V/cell, temperature compensated, which means in the dead of winter I’m up around 2.55-2.58V/cell. Yuuuup.
SLI (Starting, Lighting, Ignition) batteries in a car or truck are the opposite - they’re fairly light, have a ton of very, very thin plates, provide a rather impressive amount of power for cranking an engine, and don’t tolerate deep discharges at all. My experience is that about two deep discharges ruins a car battery. They’re designed to sit fully charged, provide a boatload of amps for a very short period of time, discharging a few percent in the process, and then be recharged back to full.
Standby batteries (like your UPS has, emergency lighting systems have, etc) are designed to be fairly light, to be stable at a float charge voltage for basically their entire life, to be fairly long lived, and are designed for a handful of deep discharges in their life. They don’t tolerate daily cycling, and typically won’t be terribly happy with a high charging voltage (they’ll gas and vent). Toss nearly 2.6V/cell into them (say, 15.5V) when cold, and you’ll almost certainly hear some nice hissing as they vent - and vent hard.
I’m not saying they’re for sure useless, but if they weren’t, nobody would have gotten rid of them. And even if they were fine when decommissioned, getting deeply discharged like they are will ruin them nicely.
Play with them if you want, but I would be surprised if any of them were in usable condition and above about 50% of rated capacity.
Reliable, yes. Efficient, maybe. Tricky, yes. I’ve done this before - you have to find a “dumb” charger, because the smart battery chargers that are all the rage these days look at a battery that never stops drawing current as shorted/failed/etc, and will refuse to keep charging into it. That puts you back into the dumb, transformer based buzzing chargers (12V/6A sort of auto chargers) that are far from efficient or good for batteries in the long term, but… it will work.
Put a load on 'em and see what their capacity in amp-hours is, or if they can even hold a 1-2A load without sagging down to 10V.
Core charge returns for buying good batteries?
Counterweight for a small trebuchet?
Ammunition for a small trebuchet? Probably not a great idea, picking up shattered lead battery bits doesn’t sound like fun…
Thermal mass for a shed? Stack them with space between them and run a fan through them to store and release heat.
You don’t have a massive pile of batteries. You have a massive pile of dead or mostly dead batteries that someone else gave away. 
Actually lead acid batteries (of nearly all types) are almost 100% recyclable. It’s impressive how efficiently they can be re-used. Batteries are limited-lifespan wear items that need periodic recycling/refreshing. This is by far the best (in a whole-system view) thing to do with so many of them in such a degraded condition. I know it’s not as fun to just “give them away” in that sense, but yes, if you get core charged, it’s a good idea to use these as counterbalance. Think of them as empty beer bottles - while sure, you can come up with a lot of (mostly useless) things to do with them, unless you’re building a cob house and need the insulative properties (the bottles, that is), it’s just better for the whole system to return them to circulation.
alright, at this point i’m cutting my losses on this stupid UPS 
Maybe keep a few of the components that I pulled off, and a few good battery packs for benchtop voltage supplies. They put out a couple of amps no problem running a 12v bulb and motor i had laying aroaund, at least for the few minutes I cared to test.
Well, thanks for not letting me get too far down this pointless rabbit hole .
No problem! Been there, done that, recognized the signs…
“I got X for free! I must make it work! It’ll only cost $Y to get it working again!”
“… yeah, but for, like, less than half of $Y, you could get a thing that does what you want without having to hack on it.”
“BUT FREE THING MUST MAKE WORK!”
Well thats something interesting I learned reading the OzInverter book that I guess people in Europe or Australia are doing with them. I’m not sure what sort of “smart” charger they’re using but they call it DC coupling. Rather than do what the Magnum/Outback setups do with a big automatic transfer switch that transfers your load between grid and your battery+inverter, they combine the power at the battery bus and are able to “blend” grid power and solar power, and always run their loads through their inverter - either from solar panels, grid, or batteries.
The benefit to this method compared to the setups I’ve seen with transfer switches, is you’re not cycling your batteries as much if you don’t need and it seems like you’re usually able to get more out of your panels.
The question is efficiency, they work hard on the design to get the idle consumption of the inverter down to around 30 watts. I’m not sure what the efficiency of the 220VAC to 48VDC converter is.
Well, interesting and fun to think about, opened my eyes to a new way of doing it rather than either hoping your utility has a good grid tie policy, or just going fully off grid.
That’s certainly a way to go about doing things. Always inverter driven, with solar doing the work it can and at some point grid power stepping in as a generator.
I’m not sure I agree about either it letting the panels do more or being easier on the batteries, because the two are mostly at odds with each other - you can’t export to the grid with that sort of setup.
So, either you’ve got the system running in a “plenty of sun off grid mode,” where the panels do the work, grid tie is rarely used, and you’re cycling the batteries daily, or you’re in a “grid priority” mode where the panels do very little work, and you use them for backup. It doesn’t strike me as a terribly cost effective way to run things all considered, but AU is weird.
The main advantage of that sort of system is that it’s a beautiful UPS - as long as the inverter runs, you have uninterrupted power. But most automatic transfer switches are fast enough that nothing really cares about the blip - almost everything tolerates a dozen or two ms of transition time.
Still better than a DC 12V bus for the house, though! 
honestly i was going to make a thread about that genius idea i had too. It seems like a good idea, leverages equipment from marine/auto/RV industries. 80% (by quantity of things not energy consumed) of the stuff I “turn on” is low power, and has a power brick that converts to DC, or even plugs into a USB. Obviously as a retrofit its an insane amount of labor but is it that crazy to run 12v and 120v service throughout a house side by side?
True I was specifically thinking about specific scenarios and assumptions - that the offgrid setup “wastes” a lot of PV output being in float charge mode in your solar office when it could be outputting at maximum power point, and reducing the grid load from your laundry, fridge, and whatever else. Meh, its probably a problem of premature optimization to worry about this, and the answer instead is to just get more panels whatever setup you have.
Yes, it’s insane. At least if your goal is anything reasonable, like being environmentally friendly, saving money, etc.
I offer some poetry to make my point:
Little Johnny played with mega-amps
Little Jonny ceased to be,
For as we know, Ohm’s Law says,
“Bitches, I squared V!”
If your goal is to spend a lot of money on copper to have an inefficient power system with a ton of losses, sure. 12V is fine. Have a it.
But even minimal amounts of power, transmitted at 12V, either require insane gauges of wire, or you lose a ton of power. If your goal is to save power, run your house at 240V. You get 25% the resistive losses, and most switching power supplies are an awful lot more efficient at 240V compared to 120V.
If I want to run 12W @ 120V, 100’ of 12AWG, my losses are basically zero - 0.1A, 0.026% voltage drop. Run it at 12V, same load, 1A, 2.65%. Hrm. At 120W, though, 12V/10A, we have 26.47% voltage drop (power loss) vs 0.26% at 120V/1A. Hrm. Dang. To get losses at 120W down to a sane level for 12V (sub-1%), we’re at 4/0. That stuff ain’t cheap.
12V wiring requires either stupid wire gauges (insanely expensive), or basically no power transmitted.
And… RV stuff? Have you priced that rubbish lately? You’re usually cheaper with an inverter and a sane bit of equipment than a “12V RV” version of something. They’re priced for retired folk with a few million in the bank and no sense of value.
Certainly. I waste a lot of my office PV output. But it’s a pain in the rear to tie it to the house system to export, so… not going to do so.
Yeah, wire costs and diameters would be bonkers. I’ve got a couple radios that can pull 5-15 amps at 12v on max power. That would likely take 8 or 6AWG wire just to run my power supply from the other side of the room much less the other end of the house.
It seems to me there are three main engineering challenges with such a setup:
*the rules dictated by number 3 may or may not have anything to do with the goals of numbers 1 and 2.
#3 is the challenge… yeah. 
From conversations with local solar installers, The Roadblock (JS):
It’s pretty well nonsense. Sadly. I wish I had a better answer, but in Idaho? You keep him or his minion happy, or, fuck you.