Those UPS devices you buy for your computer usually have a gel-cell battery that lasts for a few years. Less if your power goes out a lot. When you replace them, you pay a bundle, even if it's a standard cell. This short Instructable will demonstrate how to rework an older UPS for more capacity with cheaper battery power.
The picture shows some sample UPSs and an example of the gel cell from one of them. The UPSs come in various capacities and, although you can boost the capacity, the output power is fixed. When you start out, make sure that the UPS you're going to modify will provide the volt-amps and power that you need. Also note that the volt-amp rating is higher than the power rating. The difference is because AC powered devices have a power factor. Check online for more info about this. Another, similar Instructable, also warns against trying to max out the capacity of your UPS because some use transformers that will run continuously at the rated output. It really depends upon the quality of the UPS, but plan to run at not more than about 75% of rated output capacity.
Another thing to consider is whether or not your scrap UPS has AVR or Automatic Voltage Regulation. You'll want this if you can find it.
The picture shows some sample UPSs and an example of the gel cell from one of them. The UPSs come in various capacities and, although you can boost the capacity, the output power is fixed. When you start out, make sure that the UPS you're going to modify will provide the volt-amps and power that you need. Also note that the volt-amp rating is higher than the power rating. The difference is because AC powered devices have a power factor. Check online for more info about this. Another, similar Instructable, also warns against trying to max out the capacity of your UPS because some use transformers that will run continuously at the rated output. It really depends upon the quality of the UPS, but plan to run at not more than about 75% of rated output capacity.
Another thing to consider is whether or not your scrap UPS has AVR or Automatic Voltage Regulation. You'll want this if you can find it.
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Signing UpStep 1: The Guts
First, for safety's sake, unplug the UPS. This pretty much goes without saying. Also realize that the battery inside the UPS may be charged, so do not short circuit any metal parts inside the box.
When you open the UPS box, you'll usually find either one or two gel cell lead-acid batteries. You're going to replace it / them.
What you'll need:
1 scrap UPS - but it needs to be a WORKING UPS!
4 feet of #10 copper wire (2 feet of red and 2 feet of black if you can)
You may need to adjust this length, but keep it as short as you can tolerate.
4 spade lugs (two mating pair
2 ring lugs for single battery or 4 if you have two in the UPS
1 or 2 marine, deep-discharge batteries (85 - 120 AH capacity)
Tools:
A drill with bit set
Crimper for the lugs
Wire stripper
Sandpaper or a small file to smooth out holes in plastic
Some notes on the parts: look at the pricing of the batteries and get the capacity that gives you lowest cost per amp-hour. Sometimes the 110-140 AH batteries are only a little more than the 70-90 AH ones. Check warehouse clubs for good pricing. Sometimes you can reclaim the core charge with an old motorcycle or car battery you have lying around. Make sure that what you get is a deep-discharge type battery. Some batteries are labeled as marine, but not deep-discharge.
Make sure that your battery has adapter studs that clamp to the lead posts. Then, get ring lugs from your hardware store, electronics store, or online store that will fit over the threaded studs and also accept #10 wire.
You can either get two pair of mating spade lug connectors, or get one set that are the mating connectors to the ones that come from the UPS. In the picture, these are the black and red wires that connect to the batteries.
Note the blue wire. The batteries are in series in this UPS, so it requires 24 volts (black terminal connected to red terminal). Do not try to power it with one battery if it comes with two! Get two more ring lugs if you need two batteries.
When you open the UPS box, you'll usually find either one or two gel cell lead-acid batteries. You're going to replace it / them.
What you'll need:
1 scrap UPS - but it needs to be a WORKING UPS!
4 feet of #10 copper wire (2 feet of red and 2 feet of black if you can)
You may need to adjust this length, but keep it as short as you can tolerate.
4 spade lugs (two mating pair
2 ring lugs for single battery or 4 if you have two in the UPS
1 or 2 marine, deep-discharge batteries (85 - 120 AH capacity)
Tools:
A drill with bit set
Crimper for the lugs
Wire stripper
Sandpaper or a small file to smooth out holes in plastic
Some notes on the parts: look at the pricing of the batteries and get the capacity that gives you lowest cost per amp-hour. Sometimes the 110-140 AH batteries are only a little more than the 70-90 AH ones. Check warehouse clubs for good pricing. Sometimes you can reclaim the core charge with an old motorcycle or car battery you have lying around. Make sure that what you get is a deep-discharge type battery. Some batteries are labeled as marine, but not deep-discharge.
Make sure that your battery has adapter studs that clamp to the lead posts. Then, get ring lugs from your hardware store, electronics store, or online store that will fit over the threaded studs and also accept #10 wire.
You can either get two pair of mating spade lug connectors, or get one set that are the mating connectors to the ones that come from the UPS. In the picture, these are the black and red wires that connect to the batteries.
Note the blue wire. The batteries are in series in this UPS, so it requires 24 volts (black terminal connected to red terminal). Do not try to power it with one battery if it comes with two! Get two more ring lugs if you need two batteries.
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Here's someone that did it, and it overheated.
http://www.instructables.com/id/SYB2G6JFMZAFYV2/
Here's 2 more builds that mentions overheating
http://www.techspot.com/blog/137/turn-a-small-home-ups-into-a-giant-ups-diy/
http://old.drcheap.com/home/hoh/upsbattery/
There's another build thread that showed a melted UPS after connecting a car battery to it, but I can't find it anymore.
Here's a proper build with a large UPS.
http://www.ocforums.com/showthread.php?t=584475
People just gotta start on a good platform, no point upgrading a crap UPS. The 1250VA unit I'm using now was free. Just check out garage sales, craigslist, and localy on ebay. If you work in a large office, talk to someone in IT, they normally pay companys to dispose of this type of equipment.
As for the suggestions, yeah, all of them sound good. Except.....well, there are no garage sales over here at all (it seems to be pretty much a US custom). Also I can pretty much forget about craigslist and eBay as well (no category for my locale/no eBay in my country). The only place I can think of for research are the junkyards and battery/IT equipment recycling facilities. I'll check out the former, but have no idea where to find the latter (I've been working in a large office, unfortunately they've managed to kick me out rather quickly so it's out of the question for now). Thanks for the advices anyway :P
In the EU we have some laws making recycling of such stuff mandatory. This is why I figured I could find such company. And yes, I could use some foreign e-Bays as well (PayPal doesn't try to make your life miserable anymore when you're trying to use it from Central/Eastern Europe like they used to), but I think the postage would be way more than the price of the thing itself (especially if the seller would include the -possibly defective- battery as well). Basically this is why I prefer a local "supplier". I've ordered quite a few other things from such sites though (books, Arduino etc.), but there's also another problem. You see it's been a custom of sorts for companies in Yankeeland to ship only within the continent (many times they don't ship even to HI, AK or outside territories). They aren't the only ones to do this on eBay though, but the US companies seem to do it with e-shops as well. I could circumvent this limitation per se but it wouldn't be feasible for small amount of goods. So my options are pretty much limited. Still, this issue isn't that pressing for me. Thanks for the tips though.
My understanding from my research so far is that even most sealed batteries are valve regulated thus allowing a little gas to vent. This is only if you over-charge however and I think UPSs should be pretty good at avoiding this. I will make or modify a box for my rig, ventilate it well and I will place it in a big airy part of the house. I found heaps of info from battery university - google it. Also, I think you should avoid calcium infused lead acid batteries because when at 100% they typically sit at a higher voltage than non-calcium which means that the chargers in UPSs may not charge them fully.
Bear in mind there are NO SMOKERS in my house/office - EVER, but truly - using a UPS to process battery power into 120VAC is a great idea as is boosting the run-time of your UPSs.
I add only one warning which has been said here before repeatedly:
DO NOT OVERLOAD YOUR UPS !
The bigger battery is for stand-alone power or added runtime - NOT for supporting a load beyond about 60-70% of the UPS's rated capacity.
If you can find them:
My all time favorites are the really old, metal-cased APC units connected with solid house wire to lawn tractor batteries.
The hydrogen gas released by any lead/acid battery has a very obvious odor and is unlike anything else -and I have never, never, never had any problem doing this indoors.
One important point IMO:
Since there is always the possibility for leakage I recommend ALWAYS placing any such battery or batteries into a plastic tub like a dollar store dishpan to catch any dirt or possible leakage if anything ever needs catching.
Solar enthusiasts:
If you seek out your local PC recycling freak who has connections with places that recycle servers and big UPSs you can use those super-high quality inverters with your batteries and save a bundle instead of branded solar-only inverters.
Last word of my opinion on this matter -> this IS the Instructables site for DIY'ers and if anyone who reads these is too afraid to experiment and learn by doing then this I would recommend ONLY buying ready-made, UL approved devices and leaving the DIY to enthusiastic DIY'ers.
Happy DIY'ing !
If it's in a closet, it's not likely to be plugged in - most closets don't have outlets and said wife, husband, girlfriend, or boyfriend that made you hide it isn't likely to want a thick cord running from a wall outlet into a closet, and then more cords coming out of the closet into a nearby computer, monitor, etc.
Caution yes. OCD no. If people read the article and comments and recognize the limits, they can avoid the pitfalls. That's what this is all about. You can find some hazard in just about everything posted here, but then you wouldn't do anything.
Bryan A. Thompson
bryan@batee.com
http://batee.com/projectsanddesigns/offgrid/upsinverter.htm
if you can find a place that sells this to the public
http://www.theinstallbay.com/product_section.php?pn=1
nothing special but cheap :)