How to build your own UPS

Whether your end improvement is a functioning office, or a longer game of Unreal, uninterruptible power supplies are an essential part of keeping your kit up and running. In case you were wondering what goes on inside the little -- or, as the case may be, big -- boxes that sit next to power outlets, icrontic has a how-to for constructing your own UPS. If you're not up to the task of constructing your own, then there's also advice about which type of off-the-shelf UPS is for you. Now all you've got to worry about are other, human based, interruptions.

[AJ @ Oct 14th 2007 3:07AM]

ZAP!!

Never mind...I'm too sleepy to comment anything useful. Good night, everyone!

[Chris @ Oct 14th 2007 3:14AM]

Step 1: Buy thousands of brown trucks
Step 2: ?
Step 3: Profit

[coffeepot64 @ Oct 14th 2007 4:51AM]

Damn! I also missed step 2...Did anyone get step 2?

[Jeff P. @ Oct 14th 2007 1:33PM]

Step 2: Dress in ugly brown shorts, socks, shoes and shirt
Step 2.5: Deliver billions of packages

[ed @ Oct 15th 2007 12:15AM]

LOL

coffepot - I am not sure if you are being sarcastic or not... but it's a reference to South Park. The little elves with the pants.

[Othello @ Oct 14th 2007 3:21AM]

Somehow I don't think I'd want to trust my computers to a UPS I built myself.

[yoshi @ Oct 14th 2007 12:57PM]

Considering that all of the off-the-shelf UPS systems I have ever used were piles of overpriced junk, I'm personally looking forward to trying this! Throw in a couple deep-cycle Optima batteries and it should be fine.

[hn333 @ Oct 14th 2007 4:34AM]

I guess Engadget wants to kill us all now. No thanks, im not going to build your death trap, I mean UPS.

[nemi @ Oct 14th 2007 6:13AM]

I did something similar recently. I needed more up time for my server and related peripherals in my basement. So I took an old UPS, removed the gel pack and wired the UPS to an old (but working) spare car battery.

The UPS has a low charge current so it takes several days to fully charge the battery but my power cuts are far less frequent so it works well. The run time is now over a hour vs. 10 minutes before.

For safety I only used a sealed battery. It is located in my non habit ed basement with reasonable air flow. I placed the battery inside a "battery box" (~$10 from a car / marine parts store).

For extra versatility I have a 12V car power socket mounted in the battery box and the ups connects to it with a 12 male plug. That way I have a convenient, always charged battery to take with me camping (to use with my portable inverter that plugs into a 12v car power socket). Aside: I put the gel pack back in place for these trips.

Also having a fully charged portable car battery available at all times has also been very handy in the last few months to jump-start both a car and a lawnmower. :-)

[Eric @ Oct 14th 2007 10:26AM]

Car batteries (Starting, Lights, Accessory type) are the worst possible solution you can use. At least get yourself a deep cycle marine if you want to go low end. A better solution (and much, much longer runtime) would be to get 2 6VDC golf car batteries, if you have the space. They do need to be vented, but so does your car battery. If you cannot vent, look for batteries labeled as safe for airplane use. They have caps that capture the H2 that is generated when charging, instead of venting it into the atmosphere.

I use 3 96Ahr gell cells (removed from service at work) on my solar array to provide 12V lighting, and to run my radio shack. Car batteries really discharge quickly and the plates are too thin for deep cycling. From what I've found, most UPS inverters expect to see a higher voltage than can be provided from a lead acid battery. A better solution would be something like this:

http://www.xantrex.com/web/id/41/p/1/pt/24/product.asp

Of course that is an expensive way to get AC. However, the unit is designed to keep the batteries in good shape, and it is a true sine wave, unlike just about any UPS made. Also, the inverters in a typical UPS aren't made for long runtimes and generate a lot of waste heat (not that these are all that efficient). The electronics in this type of unit are made to run continuously.

Another solution is to use laptops and DC/DC converters. Greatly increases the run time on a battery.

[Matias Korhonen @ Oct 14th 2007 7:02AM]

I'm sure that's real safe...

[Unbangyourmom @ Oct 14th 2007 9:25AM]

My 1000VA Conexant UPS died a year ago. I'm thinking of hooking up an extra car battery to it. Think it will work?

[michael @ Oct 14th 2007 9:34AM]

What's wrong with FedEx? I love FedEx!

Just joking.

[teasphere @ Oct 14th 2007 10:03AM]

OK, just since no one else has mentioned it...

"I have a fully kitted-out office at home with a workstation that runs two PCs, a 4-in-1 digital scanner/printer, an inkjet printer, a DSL broadband router, a wireless network router, and two sets of speakers. There are also a fax machine, and a mobile handset that is useless when its base goes dead."

Umm, maybe this is why South Africa is having so many power issues and unable to keep up with demand? Just a thought. May I be the first to introduce you to this great technology called a "laptop." Then get yourself *one* printer/scanner/copier/fax, a wireless DSL router, a hard wired phone, and a single set of speakers.

Maybe try to work within the constraints rather than just building a massive UPS. Idiots.

[Ohng @ Oct 14th 2007 10:13AM]

Perhaps his requirements are a little different than yours. I wonder if it's safe to say that not everything can be done on a laptop.

I've got one computer at home for working on, with three monitors attached. Another couple are servers. One is strictly for the kids, so that their use is isolated. Funny enough I've also got some of the smaller bits of electronics that he mentioned, including a phone.

I'd have a hard time compressing that all into a single laptop. I must be an idiot too.

[Shawn Garringer @ Oct 14th 2007 10:18AM]

Yeah! Who said they could have the same standard of living as those of us in the 1st world anyway?? And no more color TVs either, B&W only, color uses too much electricity!

[brokenkeyboard @ Oct 14th 2007 10:42AM]

so, he could replace everything in his office to draw less power, and still have brownouts (at best, they would be less often)

OR, he could build a good UPS. (which considering what he says about his power utility, he would need some sort of UPS anyway.)

I think that the choice here is pretty obvious. Its real obvious which would cost less.
Idiot.

[teasphere @ Oct 14th 2007 10:43AM]

Well, to each, their own. If you honestly think all of that kit is necessary when knowingly in a power crisis then yes it is idiotic. That's like watering your lawn when in a 5 year drought and people don't have enough water to drink or live off of. Sure, go ahead... I'm a geek who loves his toys just as much as the next, but reality has to set in at some point. Maybe he needs two PC's, fine, but make sure you have two of the most power efficient components possible for the tasks they are needed to do. I'd also be hard pressed to find a task/game that couldn't be done with a laptop.

This attitude towards technology isn't sustainable in the least. If you honestly think he couldn't consolidate some of that gear down then you are crazy. He then even goes on to say he runs Folding@Home which pegs his CPU's 100% for prolonged times for no real reason (yes, it is helpful but in a power crisis it is a bit excessive) I knew my addition of the word "idiots" would be slightly inflammatory, but it is the truth... to willingly be wasteful even if not in the midst of a problem is idiotic.

[JeffDM @ Oct 14th 2007 11:10AM]

I think you have some misplaced assumptions. While there is some merit in what you say, I seriously doubt that electronic equipment is taxing the grid so much. Most of that equipment there, even when combined, is fairly power miserly as a whole. There are bigger fish to fry here. If you're actually concerned about the grid, the money spent on a "laptop" would be far better spent on replacing a less efficient appliance with a more efficient one, and replacing incandescent lights with something else. In most cases, lighting and appliances are still far more power hungry than the electronics in the same house, so spending the money where it makes the biggest impact is the thing to do. If you're running a business, you'd probably still want a UPS, even if only to run the printer and router.

[insertAlias @ Oct 14th 2007 11:59AM]

First of all, since the guy's wife "runs a busy bookkeeping business," and the workspace is set up for two, I might guess that she has an employee that works on the other computer. How do you suggest that they both work off of the single laptop that you wanted them to buy?

I can see some of your points, but you are seeing things only from your point of view. ("I'd also be hard pressed to find a task/game that couldn't be done with a laptop.") What if your machine is a server? Should you buy a laptop for that and then run back and forth every three hours to plug it in and then unplug it?

Just because you would be pressed to find something you couldn't do with an expensive laptop, not everyone has the same luxury. The others are right...there are way more energy-wasteful appliances in the house that your ire should be directed at.

[teasphere @ Oct 14th 2007 7:39PM]

I still think you are all missing the bigger picture here. My suggestion of laptops was to replace the PC's. They draw more like 40-65W instead of 250-300W each (and another 50-150W for the monitors), and have their own built in batteries which rival the capability of his UPS. A number of his devices were redundant and that also is slightly wasteful.

Again, appliances, lightbulbs, etc. are also great areas to tackle. The point I was making is that in times of trouble you need to give up some comforts to better the situation. Imagine if every S. African household had two PC's two printers, two routers, etc. all running daily... now try cutting that in half (or to even one laptop and one PC) and you have a substantial decrease. But it is easy to have the self-absorbed "bah! let someone else worry about it and change and make sacrifices *I'm* too important and *special* to have to do without." B.S.

I make sure I have efficient appliances, CFLs, computers/laptops, and habits and it is not to save money or because of shortages... it is because it is wasteful not to. Everyone *can* do it, but it's easier to make a hundred excuses why you shouldn't have to or won't.

[Nex @ Oct 14th 2007 9:36PM]

ya and because there is a shortage of gas... so your garbage truck will start requiring you to hand carry your trash to collection points.. and your mail will no longer be delivered to help reserve gas.... you see how asinine that is.. i understand the need to conserve.. but, who's to say the man doesn't already have alternate power sources.. many people where i live have solar cells on their roofs.. im sure you do something that is wasteful, like throwing away food that those poor kids in Africa would kill to eat.. don't be so quick to judge.. as the bible says, he who has no sin may cast the first stone.. nobody's perfect.. everyone has their own wasteful practices..

[teasphere @ Oct 15th 2007 10:05AM]

So do nothing then. Because "the man" is holding out, because neither you nor I can be 100% perfect in our attempts, because, because, because... how about doing what you can? That's all I ever said, and is all I am saying. Again, small changes done by everyone do add up even if you continue to be wasteful in other areas. But doing nothing is the most wasteful position.

[cokebottle tuque @ Oct 15th 2007 11:02PM]

Don't let them get to you. One of my teachers has a similar attitude about his ancestral home and how he has kited it out, an ac in every window and the health of the grid and every one else be damned, oh and does he ever bitch about the quality of the power service. There can be an argent streak amongst African geeks, and clearly every one that points this out is a racist. To the rest of you note I never said anything about us Americans and that may erk you, ya we can be morons to but thats not the subject.

"As a result, I have collected all manner of uninterruptible power supplies which are linked to all the computers scattered around my house" Yes clearly he is concerned with his personal power consumption, yes running folding at home is normally waste full.(When faced with the choice of using an 1KW electric heater or 4 old desk tops running folding@home to heat my apartment I chose the old desktops)

The guy obviously has cash to spend and if he replaced his desktops with new laptops he would probably see an over all performance gain at 1/3 the power consumption, even replacing the CRTS with LCDs would be an improvement(which evidently he has since done.). Chances are if he is running folding@home he never turns his computerS off, so don't tell me he would be better off getting a new fridge.

[LukeA @ Oct 14th 2007 11:38AM]

Most people who will try to build their own UPS will end up with a VIPS.

(Very Interruptible Power Supply)

[huh @ Oct 14th 2007 12:09PM]

OK, this has little to do with the article, but maybe someone can help.

I put my projector (a Sanyo Z3) on an APC Back-UPS® ES UPS to theoretically save the bulb in case of a power outage. There hasn't been an outage, but once while watching a movie, for no predictable reason (there was no power outage) the UPS beeped and went offline, taking the projector down (fortunately the bulb didn't blow). I'm guessing this is because the projector's wattage requirements can exceed the UPS', but can anyone let me know if there is a good solution?

[Kurtis @ Oct 14th 2007 5:12PM]

no

[huh @ Oct 14th 2007 5:15PM]

OK.. wanna buy a UPS?

[Shane @ Oct 14th 2007 6:39PM]

You CAN run a projector on a UPS, just make sure that the UPS is sized appropriately. If the load is more than the UPS can handle it would do exactly what you describe when a power glitch occurs.

I am guessing you would need a minimum of 1500 VA. In addition, make sure you get a GOOD UPS. The APC UPS units come in various quality levels. I prefer the SmartUPS units. They are a good compromise between price and performance though APC does make better ones as well.

[huh @ Oct 14th 2007 7:43PM]

Thanks Shane, that's what I'd think, hopefully there are no other issues.

[johnzilla @ Oct 14th 2007 4:03PM]

Meh. a decent UPS is about $99 or less from Costco. I don't see the advantage to building one yourself...I have two in my office (one on each circuit) and I have one on my home theater rig. I can't run for hours but I can certainly run long enough to save my work and disconnect. I had my house's electric service cable replaced recently, and ran on UPS when they shut the power off. No problems whatsoever and had battery to spare when they connected the new cable about 15 minutes later.

[Shane @ Oct 14th 2007 7:13PM]

Technically in this article the guy isn't really "building" a UPS...He is connecting an off-the-shelf inverter to a bank of batteries. I did something similar to this with mixed results. The results definitely vary depending on the quality of the inverter you use. I used inverters from a company called "Dimensions Unlimited". As these setups failed I just replaced them with UPS units from APC. I still get about 30 minutes to an hour of runtime from the APC units. The inverter and battery setups were just way too bulky for the limited space I had available.