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12v solar or battery powered PSU. Can it be done?

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September 14, 2010 6:55:32 PM

I think I saw a 300 watt 12v on ebay a few years back with a positive and negative input from battery banks. I Imagine one would need a smooth steady flow of 12v and not 13v or fluctuation. Have you guys and gals ever heard of such a PSU being sold or made? It would only need to put out 12v and 5v. I do know what an inverter is and that it might be a power drain to run one all day and night as well. Any thoughts on this would be splendid. :o 
a b ) Power supply
September 14, 2010 7:58:10 PM

google picopsu
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September 14, 2010 8:18:22 PM

shovenose said:
google picopsu

With all those K's in there.. I gotta wonder. :pt1cable: 
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a b ) Power supply
September 14, 2010 8:53:51 PM

Surely it could be done. I have not looked into it deeply, so I can't point to existing products.

BUT here are the challenges.
You need minimum 300W for a small desktop, and perhaps 600W for a mid-range machine. Assume 75% efficiency, so you are looking for 400W to 800W power consumption at max. Now, machines run lower than their PSU's max, so derate that and suppose the average long-term consumption is still only 300 to 600W. From a 12 VDC battery that requires 25 to 50 Amps continuous draw. That is comparable to having your car parked and turned off, but with the headlights left on High-Beams. Ever done that by mistake? How long before your car battery was dead and it would not start? And how long did it take the garage to re-charge your dead battery for you? Oh, how were you planning to recharge your battery system?

Actually, one common type of unit that does this are the Uninterpretable Power Supply (UPS) systems that keep themselves charged in preparation for emergencies, and supply power when needed to keep your computer running. They are more complicated than OP asks because they take the time to invert their battery's power back to 120 VAC so you can just plug in, but they do much of what OP asks. A quick look shows units for $130 that can supply 630W for 2 minutes, or maybe only 350W for 10 minutes. For $1100 you can get one that lasts 18 minutes at 800W output and MIGHT get you an hour for a small computer. I know, UPS's are much more complex and hence more expensive than OP asked, but you get the idea - this is neither simple nor cheap to do.

As for solar power, I guarantee that, if you go to a store that specializes in solar cell power systems for off-grid locations and ask for a 500W system you will NOT like the price! Oh, and I hope you have a spare handy roof to mount it on, because it's gonna be a big unit!
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a b ) Power supply
September 15, 2010 5:38:36 AM

Solar panels are not cheap here's an example of one that can produce up to 216w of power for $872.50.

http://www.amazon.com/Sharp-ND-216U1F-216-Watt-Module-p...

However, you simply cannot connect it directly to a laptop or PC and expect it to power up. Power production varies during the course of the day depending on cloud cover and angle of the sun compared to the position of the solar panels. It assume it's best to be able to tilt the panels towards the sun as it moves across the sky. That another expensive piece of hardware.

Solar panels should be connected to a large bank of car batteries to store electricity. I suppose you'll need a converter between the solar panels and the battery bank. Additionally, you'll need another converter between the battery bank and your laptop / PC to provide electricity at 115v -120v and 60hz.

Overall, let's just say you will need several thousand of $$$ to make this possible. Great if you have the money to spare / are extremely environmentally conscious / space for the entire setup.

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a b ) Power supply
September 15, 2010 7:04:07 AM

You could try wind power instead. It worked well for Holland in the 16th century.
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a b ) Power supply
September 15, 2010 9:08:46 AM

2 easy ways ways to do it:
1. You could do it using a standard pc PSU and using an inverter to bump the 12v back up to 240/120 or...
2. You could probably rig up a UPS with solar panels to charge the battery in it and run the PC off that.
Rigging anything up to go directly into the PSU, bypassing the primary stage or using a custom PSU would be a bit risky and potentially dangerous, and I certainly wouldnt trust one off ebay. It would only be worth getting if it were through a reputable company that meets the electrical safety standards for your country.

If your really into solar power, just get some proper solar panels to put on the roof of your house. Depending where you live, when your not using all the power, it goes back into the grid and you can get money back from the power companies, effectively selling the power they are generating. It would pay for itself after about 5 years or so....I dont think it would be worth the money and effort for such a small single purpose use such as running 1 computer.
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a b ) Power supply
September 15, 2010 10:46:05 AM

I guess , the easiest way to do it would be to buy an inverter listed here
http://www.amazon.com/Cobra-CPI-1575-Power-Inverter/dp/...

Hook the input onto your 12 Car battery, connected your solar panels to charge it up.
And on the output side have a UPS about 1000KV and then connected to you rig.

The inverter and the battery will give you a backup of about six hrs depending on the number of batteries you connect to it, and the UPS should give you the stability required just in case of a slight fluctuation which usually does happens every now and then.
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a b ) Power supply
September 15, 2010 11:09:06 AM

Do you happen to have a pet or treadmill? If so, here is what you do. You crack that sucker open, speaking of the treadmill of course, and you set up a pull system so that when it spins, you spin something to make a battery charge. If you have a dog, just tie some desirable item to the front, and let him have at it. :lol: 

On a more serious note, this IS possible, but is no where near practical. From my experiences, the only way to go with solar panels is all out or not at all. If you want solar energy, you need to shell out 40K+ to mount them on your entire roof, something that would take likely more than the living lifespan of the house to get back. Buying smaller little kits is even worse, as you would likely need to spend $1000-2000 to power a computer. Not terribly practical.
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September 15, 2010 4:25:57 PM

Yeah, I have powered 400 watt home stereo's with 4 15" woofers on a sunny day with just panels and a small garden tractor battery.. Just to show people (that are still ignorant) that solar energy does work. I guess they work for 20 years before need being replaced with no 16th century mentality of bartering for the king's power grid supply. Black outs do not effect use and I have been using a laptop and modem on some battery banks and small 400 watt array for 3-4 years now. I guess it's like little boys who are critics of, afraid, or just to lazy to try and kiss the pretty girl. Try it yourself or quit whining like the drunk at the party that rudely barges into conversing into topics that were not about baseball to begin with. Build a Faraday cage, read "one second after" and get over this "nothing can go wrong mentality. To those of you who have offered something other than ridicule, Thanks for the input! jaguarskx.. On and on SOH!
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September 15, 2010 4:32:27 PM


That is awesome! Too bad I don't have 500 gazillion rubles to shell out and it might take away from my life's mission.. gaming. besides I need a beer and have to get my daily dose of conditioning on how eating healthfully is good with Mcdonald's commercials while I drink beer.

j/k.. cheers I :love:  Survival Podcasts.. They are free forever.. :bounce:  :ouch:  :pt1cable:  :sol:  :hello: 
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a b ) Power supply
September 15, 2010 5:16:26 PM

Typical "alternative energy" economics . . . a $5,000 *installation* to drive a 61W max PC that operating 24/7 at max would cost $64/year, including maintenance on the grid, to run if plugged into the wall. I didn't do the calcs, so not even sure the solar arrangement is *capable* of running that PC 24/7 at max.

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a b ) Power supply
September 19, 2010 5:04:43 AM

Hey come on guys, we're all computer guys here, and basically comps are logical devices, so, theoretically we ought to be logically better than the comp. right?
My UPS says : Input :220V ~8A Max
Output : 220V~4.5A
As we all know V=I*R (Voltage equals current multiplied by resistance)
There are 60W and 220W solar panels out there delivering awesome amounts of current.
If my Inverter powers three rooms for 6 hours on a single 24 V Battery (Truck)
Wouldn't it be pretty simple to hook it up to the solar panel to get it charged and have the ups run after it straight to the comp.
It ain't going to run into $$$$$ at all.
The Panel is for about 200$ and the battery and the inverter is for about 300$.
Really, this will work.......
And if we think like the rest of the mobo company's which want to go green, I think this would really make a big difference if each one of us was to be able to to do it....
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a b ) Power supply
September 19, 2010 5:18:48 AM

Why don't you start then?

Take one of those 220Ws . . . are those the ones nearly as big as your front door? . . . you know at least one of the formulas . . . spec out the batteries . . . make sure you include enough battery backup to allow for, shall we say, 3 days when the sun don't shine . . . and let us know how easy it is.

Then show us a photo of where you put the panel . . . and the batteries . . . and don't forget to put the panel somewhere you can sweep the snow off it.
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a b ) Power supply
September 20, 2010 7:41:26 AM

Twoboxer said:
Why don't you start then?

Take one of those 220Ws . . . are those the ones nearly as big as your front door? . . . you know at least one of the formulas . . . spec out the batteries . . . make sure you include enough battery backup to allow for, shall we say, 3 days when the sun don't shine . . . and let us know how easy it is.

Then show us a photo of where you put the panel . . . and the batteries . . . and don't forget to put the panel somewhere you can sweep the snow off it.


I really must say, luckily for me, I live in India :D  so we don't have to go thru all the snow anymore, since I lived in it for 8 years of my life.

Downside of this place is, Solar panels ain't as easily available here as in the States or Europe. So it is going to take me a bit of time, and sure as hell, I will post the pics and the config here.

So basically, I need just about 12 Hrs of Backup, with 12 Hrs of Daylight....
Lets hope it works...... but I sure will give it a try, just waiting to get the panels here without being damaged , since sending them back is going to cost me just as much as the panels do.
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September 20, 2010 12:57:30 PM

Twoboxer said:
You could try wind power instead. It worked well for Holland in the 16th century.


Yeah but back then computers didn't need that much electricity :D 
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a b ) Power supply
September 20, 2010 10:01:28 PM

You won't be back. The project is doomed to be an impractical, economic failure.

The sole benefit will be to prove this to one person.
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January 29, 2011 9:50:35 PM

YES!
http://www.tomshardware.com/reviews/25w-performance-pc,...

This project was an i5 cpu, not a laptop or Atom chip.
The new sandy bridge chips may do this even better.


Not only can it be done, it IS being done!
http://islandtimepc.com/marinepc.html

A 12 volt power supply is a good start:
http://www.mini-box.com/s.nl/sc.8/category.13/.f


I checked today on parts:
About $600 not including the monitor for a 12 volt PC.
Core i5 Sandy Bridge 65 watt, with 60 GB SSD, and 120 watt power supply.

PC may run 80 watts, and 22 inch LED monitor 28 watts.
2- 120 watt solar panels should keep it running as long as the sun shines.
Double that with batteries and run 24/7
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February 6, 2011 2:18:02 AM

Twoboxer said:
You won't be back. The project is doomed to be an impractical, economic failure.

The sole benefit will be to prove this to one person.


I love it when people prove stuff to me. Back 2 years ago I had 9 of those cheap harbor freight 45 watt panels (in the summer of course) on a scaffold at a flea market charging a car battery that was hooked to a 2k watt inverter and a 400 watt home stereo BlAsTiNg out of 2 15" old jensen movie speakers all day long. Needless to say it died out at night and storage is never close to input. If we ever come up with super conductors that would be amazing. That car battery served as a voltage regulator more than a storage device for that though.
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February 6, 2011 2:36:21 AM

dwebb5 said:
YES!
http://www.tomshardware.com/reviews/25w-performance-pc,...

This project was an i5 cpu, not a laptop or Atom chip.
The new sandy bridge chips may do this even better.


Not only can it be done, it IS being done!
http://islandtimepc.com/marinepc.html

A 12 volt power supply is a good start:
http://www.mini-box.com/s.nl/sc.8/category.13/.f


I checked today on parts:
About $600 not including the monitor for a 12 volt PC.
Core i5 Sandy Bridge 65 watt, with 60 GB SSD, and 120 watt power supply.

PC may run 80 watts, and 22 inch LED monitor 28 watts.
2- 120 watt solar panels should keep it running as long as the sun shines.
Double that with batteries and run 24/7


Thank you so much, your answer was worth the wait. Feel free to go nuts and post similar links if you see any. Great start. Is that the biggest monitor a 22? I would like 3 of those with a triple head 2go splitter or three head low memory graphics card. Any thoughts there with all the microatx stuff?

Cheers
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