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UPS Hacking in Hurricane Season?
kengreenebaum asks: "Perhaps not the most exciting of topic; however it is storm season and I have a couple of UPS's that need new batteries. What is the best source for high quality, long lived replacement batteries for these devices? I assume it takes a special chemistry to survive continuous trickle charging and an occasional deep cycle. Has anybody tried connecting larger capacity batteries external to the UPS enclosure to attempt longer run times? (Obviously the load capacity is based on the inverter itself and can't easily be modified) Also what software do you use for monitoring and automatic shutdown on Linux? I have collected quite a few APC and Belkin UPS's 700VA or smaller as they go on rebate/sale."
Just FYI, if you have a UPS with replacable batteries (not the crap throw-away Energizer or whatever brand ones) it's very likely that the battery inside is a gel-type sealed lead acid battery. Just take the battery out and look at the markings on them. Odds are good that you'll be able to find a replacement either on eBay or any of the cheap battery suppliers online.
Myself and a number of friends of mine have acquired SmartUPS' (typically >1400) for free, simply because they are 'broken', and a battery replacement costing around US$50 or so makes them like new. Oh, and a good SmartUPS is really, really nice compared to a standard passive device.
For the batteries, if it is maintaining the voltage at a "float voltage" the batteries can be held nearly indefintly without a discharge or worry of overcharging. Lead acids have a float voltage of about 2.35 volts/cel (based on some quick googling). They will still die after some time.
But I don't know what technology, size, or how the UPSes actually using the batteries.
If I was DIY a UPS, I would have about 10 12Volt batteries (no transformers...), drive them off a full-wave rectifier, filter the power from the rectifier a bit, and then invert the power to make it back to AC and use my equipment off that. Advantage, I am always off the batteries, disadvantage, I have no monitoring ability and if I was to set the incoming voltage to the float voltage, it will probably take a while to charge.
If your using an APC ups, apcupsd is by far the best one to use. www2.apcupsd.com/
They wont last near as long as a nice big marine deep cycle battery. (if your UPS runs on 24 volts, 2 will do nicely) Since obviously these batteries are designed for deep cycles.
APC has a nice trade in program, take ANY UPS, send it in, and get a nice discount on a new one. Check their website out for details. (I'm sure their comptition has something too)
Now I'm sure you are still paying more than just batteries. However you get a system that is designed to work, with electronics that are not used and have no seen some unknown number of surges. You don't take a chance that the charger is broken (which may or may not break the batteries)
If you really must go cheap, inverters are getting really cheap, connect a few batteries to an inverter with a standard battery charger. You don't get monitoring, but you know when the lights go out, plus you have a lot more runtime. For extra points you can make your charger a solar system and run your computers off the grid. (Note, to get a system that doesn't waste a lot of energy you must to some research, but this theory will work)
Actually, if the UPs is worth a dam the backups aren't on a trickle charge; it should be periodically testing and charging as necessary.
Deep cycling is bad for any battery, but excercising them extends their life. I recently came across an interesting resource when doing
my own research on batteries
http://www.buchmann.ca/default.asp
Were that I say, pancakes?
I like http://www.apcupsd.org to handle my APC UPS on Linux. It works very well, and also supports some Belkin UPSes.
1. Small UPSs typically use sealed immobilized-electrolyte lead acid batteries, more commonly referred to as gel-cells. They aren't special at all, they are quite common.
2. I usually buy gel-cells cheaply at hamfests. They last quite a long time, and used ones are often a good buy. They're heavy, and while you can buy them mailorder, shipping will add up. Better to find a local supplier if you can. Lots of places sell them online though, just google (or froogle) for "gel-cells".
3. Most small UPSs have a CPU that is programmed with the approximate capacity of it's battery. Using grossly different sized batteries will likely cause the UPS to freak out, or at least not use the batteries' full capacity. Don't connect deep cycle marine batteries to your UPS's guts, it won't work right. Heck, I once had a UPS go south just because I let it sit with no battery for 6 months and the CPU lost its memory.
4. You need to be careful, because the term UPS can refer to a pussy office UPS thats basicly a bloated power strip, or it can refer to a building full of batteries capable of running a large factory for an hour. UPS components come in all shapes and sizes. A UPS is four things, and inverter, a battery charger, a battery, and an automatic switch. You can build and or buy some or all of those components separately if you wish. Look at places that sell solar power and alternative energy systems for people off the grid. All kinds of beafy power equipment.
Happy hacking!
-73, de n1ywb
www.n1ywb.com
I've used Batteries Plus to replace the batteries in my UPSs. They have the correct batteries for different types of UPSs and have been pretty reasonable on prices. They're a franchise so they're all over the US.
Slashdot: Failed Car Analogies. Amateur Lawyering. Anecdote Battles.
http://www.dansdata.com/diyups.htm
For those familiar with Dan, you know that it's bound to be interesting. What he does is somewhat of the solution described in some comments.... battery charger, batteries, inverter. He also talks about the merits and pitfalls of different batteries in UPS systems.
On average a battery will last around 2-3 years, tops.
The primary cause to battery failure is sulfitization (sp?) where sulfer crystals form on the battery plates and block the normal battery chemical reactions. This occurs MUCH faster when the battery is not 100% charged. The best thing you can do for any battery is keep it on a trickle charger, which most if not all UPS's do.
If you rarely loose power, normal batteries might be a cheaper choice for similar results. Deep cycle batteries have thicker plates for more durability, and are less likely to have the plates damaged when heavily drained. They sacrafice capacity and avalable amprage for this extra durability. Standard automotive batteries are designed to pretty much never get drawn below 70% capacity.
Unless your into some serious hardware hacking though, I'd stick with something nearly the same as the UPS is speced for.
Buy an Optima Blue Top. It's a gel cell, and they are indestructable. The Blue Top is a Marine Battery, and optima recommends them over the Deep Cycle Yellow top for UPS usage.
http://www.optimabatteries.com
I had a Red Top in my 83 GTI that was 12 years old (the battery, car was older). It started my car (which sat outside all night) on a -45 degree morning (actual -45, without wind chill). Any battery that can go 12 years and still do that is amazing. The military puts them in everything from Hummers to helicopters.
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Lead-acid batteries make hydrogen as they charge. In normal environments this is not a problem, but in the places that UPSs are likely to hide (closets, racks, mechanical rooms, under the raised floor...), there may be enough of an air restriction to cause a buildup.
It's kind of ugly when catches fire...
*whup* "Get along, little electrons. Heeyah!"
I've taken a rather pragmatic approach to the whole UPS situation. The power in my house and at my company is usually pretty stable, except for an occasional flicker once in a while, usually during a thunderstorm. My philosophy is to use the UPSs only long enough to handle a flicker or to keep the systems up long enough to do a shutdown. The power only goes out for more than 30 seconds no more than once a year or so. I don't really feel the need to spend much (any) money to handle something that only happens once or twice a year.
I can get broken UPS for free, just for hauling them away. Unless it's taken a lightning hit or something, 90% of the time the electronics are fine and the battery has gone bad.lectronics are fine and it's the battery that's toast.
how many deep cycle batteries he could chain off an APC BackUPS
Only slightly above the "toy" UPSes, APC has models that let you chain external battery units (no need to hack the hardware, which probably makes assumptions about the supported battery technology and configuration, thus limiting your options on battery choice). The last one I used had to be told through its software on the server how many external batteries it had, but then handled everything thereafter. Perhaps the original poster's units are among these? Also, APC claims to have mgt software for several Linux distros (PowerChute Business Edition Basic).
I'm really amused at how the decrease in power quality in Californa and the East is causing more ordinary people to add load (the UPS) to deal with it. My prefered defense is to start with a laptop, which has lower power requirements and smarter management to begin with plus its own battery, and then I can reduce or eliminate the UPS.
- Flooded. This is the standard lead-plates-in-sulfuric-acid design used in car batteries. These must be kept upright. Car starting batteries use a spongy electrode design for large surface area (and thus high current capacity), but deep discharging collapses the spongy structure. Deep-cycle batteries use more solid plates that can stand more cycles of surface recrystalization.
- Gel cells. The electrolyte is gelled to keep it in place even if the cell is inverted. The gelling increases the internal resistance of the cell, making it worse for high-discharge-rate applications.
- Absorbed glass mat (AGM) cells. These use a fiberglass-like mat to hold the electrolyte in place. Generally considered a step up from gel cells.
The latter two (and some maintenence-free designs of the first) are known as "valve-regulated lead-acid" (VRLA) cells. Rather than vent gasses generated by the charging process, they try to keep it trapped and have it recombine internally. If you charge them too fast, overpressure valves will open and you'll lose water irreplacably.If you can be bothered to do the maintenance (top up with distilled water every 6 months), flooded-electrolyte cells are better value for he money, but sealed (VRLA) cells are more convenient.
All three have slightly different optimal charging voltages. There's usually a trim pot inside most UPSes that you can adjust to dial it in for a different battery type.
In general, you can replace the batteries in a UPS by any other lead-acid batteries. I routinely substitute larger external batteries to get more run time. This is doubly good in that batteries that can be discharged in 15 minutes (like most UPS's normal cells) are specialty items. But a couple of big external honkers and you can get 3+ hours of run time (at work, I aborted a run-time test on the main server after 200 minutes), and you don't need to shop as carefully. Most batteries will give good service at a 1 hour discharge rate or lower, although a 10 hour discharge rate is usually used for capacity quotes. Google on "Peukert's equation" for details,
A big battery will take forever to charge, but that's usually not a problem for a UPS application. A super-cheap charger could in theory overheat, bit I've never seen a problem.
The main type of UPS that you do have to be careful about is the really cheap $99 fanless UPS. They get hot if they run near full load, and rely on the battery giving out before they overheat! You might be able to use them if you derate them a lot, but I haven't tried. If your UPS has a cooling fan that looks like more than an afterthought, it should be able to run some honkers just fine. Just wire enough in series to give the same voltage.
Remember to use thick short wires. When converting 12V to 120V, the 12V wires carry 10 times the current of the 120V wires, plus efficiency losses, and losing 1V is much worse. For the same proportional power loss, you need wires of 100 times less resistance than your AC cords. If they're 1/4 the length, that means they need 25 times the area (5 times the diameter). If you add longer wires to connect external batteries, make them thicker than the UPS's internal wires to compensate.
If your UPS runs on a higher voltage (the good big ones do), you're in better shape, but still really watch the low-voltage resistance. Thick wire, clean terminals, bolted down tight. A good crimped connection is actually lower resistance than a soldered connection, but I crimp it on and then flood the connector with solder. (A cheap 15W soldering iron will not be able to do that. A carefully used plumber's blowtorch will work better.)
If you're connecting multiple batteries in parallel, watch the wiring carefully to equalize resistance. Home solar web sites give examples. The big one is, if batteries A, B and C are connected in parallel, to connect the UPS to the negative terminal of battery A and the positive terminal of battery C. That way no battery is closer" to the UPS than any other. Also, when running big banks in series/parallel, you do want your series chains cross-connected at each "rung", although you don't need quite as thick wire.
This should not be modded down. It's entirely on topic. Another solution is to pay one of your sensible midwestern relatives to host your computer for you on a cable connection, and they get free internet out of it too.
Can be a chore to setup, but works with a variety of equipment and some good info there as well.
Anything is possible given time and money.
I have replaced several batteries in a range of APC UPSs. Since batteries tend to be heavy, it's usually cheapest to go to the local electronic supply store. (we aren't talking Radio Shack)
One caveat, newer consumer APCs have been using a special connector. With those you may have no choice but to get them from APC.
If you want to make your batteries last longer, both in runtime and lifetime, don't put more than 1/2 the rated load on them. It can make the difference whether you get one year or three years out of them. But regardless, UPS batteries are consumable.
It is amazing what you can accomplish if you do not care who gets the credit. -- Harry Truman
http://www.homepower.com/ Covers various forms of renewable energy, mainly for the home with a few businesses. The current issue is always freely downloadable in PDF format, if you register(free). http://www.homepower.com/files/midnight.pdf Is an article on a home sized UPS you can build yourself.