I have spent $70 on a 400VA 700W apc UPS, I would like to seek out another alternative that maybe better. I wouldn't mine making something that would that would cost a little more then what I paid already that would say better quality and will last longer. How long do UPS batteries last do they need to be changed every couple of years? I would like for all my computers to last 2-3 days if needed... How much are marine batteries and how do you charge them? How you know how much juice it currently has? Do you charge them periodically? And is all this in an enclosure that could pass safety regulations?
Thanks,
jonathan
On Wed, 15 Dec 2004 10:29:03 -0600 (CST), Duane Attaway dattawaykclug@dattaway.org wrote:
On Tue, 14 Dec 2004, djgoku wrote:
Reading on some solar panels that are out there I found these since my computer is using around 300 watts with monitor. I'm kinda confused on what Approx. Watt-Hrs / Day = 1200 - 1500. I know you just can't run your computer off these panels but you would need a battery of some sort for the panels to charge. But does that mean that it charges 1200 -1500 watts/ a day so you would need a couple 700 watt batties or? Most car batteries are like 300-700 watts no? not crank just the storage part if that is what it is called.
Since this stuff isn't at Walmart yet, the possibilities are only limited by imagination...
My marine battery will power my computer and the stuff on my desk for about five hours, perhaps longer. If I were going to rely on solar power, I'd want at least two days of not having to worry. I could be pendantic about math calculations and measurements and push things to their physical limits, but its never exact in the real world. So, let's make that 10 125Ah marine batteries and call it two days.
Now, we could attatch the solar cells directly to the batteries. There's only one problem though. When the batteries reach full charge, the cells will gas the water right out of them. Then the batteries are no good, except for boat anchors. We need a charge regulator that combines the output of the solar cells and maintains the batteries. The charge regulator can have its own inverter and switchgear so it can interface directly with the AC mains. Its all up to you what to get.
What do I use? I use a cheap APC power supply that toasted its batteries in the usual 2 years. When I get solar panels, I'm going to install a DC to DC converter to isolate the panels from the batteries and maintain the charge. That's because UPS supplies usually have the battery tied hot to the AC mains and extending the circuit out to the roof. We don't want corrosion of the panels or a fire hazard, so isolation is a good thing.
How many solar panels? I'd go many as possible and see about getting a peaking inverter that will take excess power and put it directly into your AC mains. That circuit will require monitoring of the utility mains in case there is a blackout and linemen are working in your back yard. We wouldn't want to energize the pole in your backyard when the guy is crimping on new connectors.
Oh, I can push an average of 200 watts of power from my exercise bike. A hamster can put out enough power to light a LED. Must not forget all sources of power that can run our computers!
http://www.otherpower.com/hamster.html http://www.otherpower.com/otherpower_experiments.html
-=Duane http://dattaway.org