Home |
Search |
Today's Posts |
#12
|
|||
|
|||
In article ,
Eric F. Richards wrote: m II wrote: Anyone hooked up any photovoltaic panels for battery charging? I've been offered two 75 watt panels and it might be fun to power some small loads through a battery storage setup. Major pitfalls? Clouds? (off to do some research...) .... I'd tell you how to do it if you weren't such a hateful ****head. In other words, you're on your own. So anyone with a concern for truth and justice, (and a bit of a flippant attitude) is hateful? Solar cells have a voltage vs. current curve that's roughly square. |___ Open Circuit voltage | ====____. maximum power point V| \ \ | \ \ "Constant" Current | \ \ | \ \ |--------------- I ^ available current depends on incident light The no load voltage is determined by quantum physics and is roughly constant. The current available is determined by the cell area and the incident sunlight. In practical terms, if you don't put the cells in a situation where they're outputting enough current to damage their internal wiring, you can hook them up and they'll provide a roughly constant current for charging a battery. You wouldn't want to use too high a voltage array, as you could damage the battery. And if the sunlight goes away, as it does every day, leakage back through the cell can discharge the battery. So the simple "chargers" I've seen where switches to disconnect the battery when its voltage got too high, or there wasn't enough sunlight. If you want to be cost effective, you get a fancy charger that transforms the load on the solar array to the maximum power point to get the most bang for the buck. Mark Zenier Washington State resident |
#13
|
|||
|
|||
(Mark Zenier) wrote:
So anyone with a concern for truth and justice, (and a bit of a flippant attitude) is hateful? If his concern was about "truth and justice" AND he'd redirect his postings to ANY politics group instead of flooding us with them here, it would be a different story. In my OPINION (note that I know when to use that word), his worldview is colored by an unfortunate anti-US bias that a small but vocal minority in Canada have. Were you here 'round 9/11/01? Remember psycho-Jim, who was mad on 9/11 for two reasons? 1) not enough Americans were killed and 2) he couldn't get any music on his radio that day? As for his point of view, I might share some of his views. But I would never, ever consider him an objective observer. Solar cells have a voltage vs. current curve that's roughly square. |___ Open Circuit voltage | ====____. maximum power point V| \ \ | \ \ "Constant" Current | \ \ | \ \ |--------------- I ^ available current depends on incident light The no load voltage is determined by quantum physics and is roughly constant. The current available is determined by the cell area and the incident sunlight. In practical terms, if you don't put the cells in a situation where they're outputting enough current to damage their internal wiring, you can hook them up and they'll provide a roughly constant current for charging a battery. You wouldn't want to use too high a voltage array, as you could damage the battery. Bzzzzzt. You were doing fine up to there. Unless you are addressing alkaline (Ni-Cd) batteries instead of Lead-acid batteries And if the sunlight goes away, as it does every day, leakage back through the cell can discharge the battery. Bzzzzt. Minor problem, not a concern unless you have massively parallel arrays. So the simple "chargers" I've seen where switches to disconnect the battery when its voltage got too high, or there wasn't enough sunlight. Bzzzt. All chargers are solid-state, PWM based. If you want to be cost effective, you get a fancy charger that transforms the load on the solar array to the maximum power point to get the most bang for the buck. Back on track again. Mark Zenier Washington State resident Obontopic: 14.325 USB hopping, a report of a tornado tearing through Panama City -- Back Beach Road. -- Eric F. Richards, "Don't destroy the Earth! That's where I keep all of my stuff!" - Squidd on www.fark.com |
#14
|
|||
|
|||
On Wed, 15 Sep 2004 01:38:02 GMT, m II
wrote: Eric F. Richards wrote: I'd tell you how to do it if you weren't such a hateful ****head. In other words, you're on your own. I'm hurt. I hate seeing a country on the other side of the globe invaded and destroyed for political and monetary gain by a bunch of corrupt, immoral monsters. There is NO evidence to support being there. I'm sorry we disagree on that and I hope you can sleep with your conscience. I must memorize this paralyzingly clear logic you use in refutation to the prior posting. |
#15
|
|||
|
|||
Mark Zenier wrote:
Solar cells have a voltage vs. current curve that's roughly square. |___ Open Circuit voltage | ====____. maximum power point V| \ \ | \ \ "Constant" Current | \ \ | \ \ |--------------- I ^ available current depends on incident light The no load voltage is determined by quantum physics and is roughly constant. The current available is determined by the cell area and the incident sunlight. I laid out the panels on the lawn today. It was overcast and I had about a forty five degree from the panel to the sun. I measured the short circuit current at **1** amp. That's disgusting. The rated current in specified light is roughly 4.5 amps per panel. I've paralleled them and put the bypass diodes in. I also added a blocking diode in each one, as I want to parallel a small toyish windmill laster on. Open circuit voltage was a bit over 20 volts. That 1 amp is troubling. I'll try again at noon tomorrow and pray it improves. In practical terms, if you don't put the cells in a situation where they're outputting enough current to damage their internal wiring, you can hook them up and they'll provide a roughly constant current for charging a battery. You wouldn't want to use too high a voltage array, as you could damage the battery. And if the sunlight goes away, as it does every day, leakage back through the cell can discharge the battery. So the simple "chargers" I've seen where switches to disconnect the battery when its voltage got too high, or there wasn't enough sunlight. Hopefully the blocking diode is of use. If you want to be cost effective, you get a fancy charger that transforms the load on the solar array to the maximum power point to get the most bang for the buck. I did a search for that when I saw your post. This one looks straightforward. I'm wondering if the paralleled setup will work ok, or if one of these is needed per panel.. http://www.solorb.com/elect/solarcirc/scc2/ This thing is getting interesting. I think I might have found a few 12 volt (six individual cells) fork lift batteries. If they're any good, I'll be in photovoltaic paradise... Mark Zenier Washington State resident Thank you kindly mike |
#16
|
|||
|
|||
Eric F. Richards wrote in message . ..
(Mark Zenier) wrote: So anyone with a concern for truth and justice, (and a bit of a flippant attitude) is hateful? If his concern was about "truth and justice" AND he'd redirect his postings to ANY politics group instead of flooding us with them here, it would be a different story. In my OPINION (note that I know when to use that word), his worldview is colored by an unfortunate anti-US bias that a small but vocal minority in Canada have. Were you here 'round 9/11/01? Remember psycho-Jim, who was mad on 9/11 for two reasons? 1) not enough Americans were killed and 2) he couldn't get any music on his radio that day? As for his point of view, I might share some of his views. But I would never, ever consider him an objective observer. Solar cells have a voltage vs. current curve that's roughly square. |___ Open Circuit voltage | ====____. maximum power point V| \ \ | \ \ "Constant" Current | \ \ | \ \ |--------------- I ^ available current depends on incident light The no load voltage is determined by quantum physics and is roughly constant. The current available is determined by the cell area and the incident sunlight. In practical terms, if you don't put the cells in a situation where they're outputting enough current to damage their internal wiring, you can hook them up and they'll provide a roughly constant current for charging a battery. You wouldn't want to use too high a voltage array, as you could damage the battery. Bzzzzzt. You were doing fine up to there. Unless you are addressing alkaline (Ni-Cd) batteries instead of Lead-acid batteries And if the sunlight goes away, as it does every day, leakage back through the cell can discharge the battery. Bzzzzt. Minor problem, not a concern unless you have massively parallel arrays. So the simple "chargers" I've seen where switches to disconnect the battery when its voltage got too high, or there wasn't enough sunlight. Bzzzt. All chargers are solid-state, PWM based. If you want to be cost effective, you get a fancy charger that transforms the load on the solar array to the maximum power point to get the most bang for the buck. Back on track again. Mark Zenier Washington State resident Can I put the solar cells in my basement? Mike Terry. Obontopic: 14.325 USB hopping, a report of a tornado tearing through Panama City -- Back Beach Road. |
#17
|
|||
|
|||
= = = ospam (Michael Bryant) wrote in message
= = = ... From: Eric F. Richards You have a fine country -- why don't you be proud of it on its merits rather than puff yourself up by belittling others, in one broad sweep, as if 300,000,000 people can be summed up by one venom-laced sentence? We have a fine country, here in the US, but there are plenty of posters in this newsgroup that belittle about 150,000,000 citizens of this country everyday with their demeaning generalizations. No rebuke of them, eh? Why can you only see things in one direction ? Ideology blinding your logic ? MWB - Maybe 'EFR' is simply using your "Telescope" ) ~ RHF [ Speaking of someone having a case of "Tunnel Vision". ] .. .. Michael Bryant, WA4009SWL Louisville, KY R75, S800, RX320, SW77, ICF2010K, DX398, 7600G, 6800W, RF2200, 7600A, Degen 1102, Degen 1103, GE SRll, Pro-2006, Pro-2010, Pro-76 (remove "nospam" to reply) .. |
#18
|
|||
|
|||
"Mike Terry" wrote in message om... Can I put the solar cells in my basement? Mike Terry. Sure, right next to your non-existent radios. |
#19
|
|||
|
|||
In article ,
Eric F. Richards wrote: (Mark Zenier) wrote: So anyone with a concern for truth and justice, (and a bit of a flippant attitude) is hateful? If his concern was about "truth and justice" AND he'd redirect his postings to ANY politics group instead of flooding us with them here, it would be a different story. In my OPINION (note that I know when to use that word), his worldview is colored by an unfortunate anti-US bias that a small but vocal minority in Canada have. Were you here 'round 9/11/01? Remember psycho-Jim, who was mad on 9/11 for two reasons? 1) not enough Americans were killed and 2) he couldn't get any music on his radio that day? As for his point of view, I might share some of his views. But I would never, ever consider him an objective observer. Solar cells have a voltage vs. current curve that's roughly square. |___ Open Circuit voltage | ====____. maximum power point V| \ \ | \ \ "Constant" Current | \ \ | \ \ |--------------- I ^ available current depends on incident light The no load voltage is determined by quantum physics and is roughly constant. The current available is determined by the cell area and the incident sunlight. In practical terms, if you don't put the cells in a situation where they're outputting enough current to damage their internal wiring, you can hook them up and they'll provide a roughly constant current for charging a battery. You wouldn't want to use too high a voltage array, as you could damage the battery. Bzzzzzt. You were doing fine up to there. Unless you are addressing alkaline (Ni-Cd) batteries instead of Lead-acid batteries Er, alkaline batteries are primary cells usually, except for those doggy Rayovac rechargeables. And why would anybody use Nicads or NiMH cells on a stationary system? Too small, too expensive. For Mike, at a max of 4.5 amps, a single marine deep discharge lead acid would probably be good enough. And if the sunlight goes away, as it does every day, leakage back through the cell can discharge the battery. Bzzzzt. Minor problem, not a concern unless you have massively parallel arrays. So the simple "chargers" I've seen where switches to disconnect the battery when its voltage got too high, or there wasn't enough sunlight. Bzzzt. All chargers are solid-state, PWM based. Not if you build your own. (Or dig back and look at a few magazine construction projects). If you want to be cost effective, you get a fancy charger that transforms the load on the solar array to the maximum power point to get the most bang for the buck. Back on track again. And if you're just hacking around, you probably won't want to spend the $$$ for one if it only gets you from 50 watts to 80 watts. Mark Zenier Washington State resident |
#20
|
|||
|
|||
(Mark Zenier) wrote:
Bzzzzzt. You were doing fine up to there. Unless you are addressing alkaline (Ni-Cd) batteries instead of Lead-acid batteries Er, alkaline batteries are primary cells usually, except for those doggy Rayovac rechargeables. Ni-Cds are alkaline, too, and I'm not talking about "D" cells, dummy. Wet cell Ni-Cds with sodium hydroxide electrolyte and a layer of mineral oil keeping the electrolyte from being exposed to air are used in a fair number of systems. They're used in locomotives to start them. Ni-Iron (Edison) cells are in those boxes at every crossing. Ni-Cds are dangerous as hell, but handle temperature variation much better than lead acid. Bzzzt. All chargers are solid-state, PWM based. Not if you build your own. (Or dig back and look at a few magazine construction projects). All *modern* ones. And a store-bought PWM charger can be had for $30. And there are designs out there for build your own. And if you're just hacking around, you probably won't want to spend the $$$ for one if it only gets you from 50 watts to 80 watts. If he's using lead-acid and the panel cannot charge faster than C/5, he can do without a controller altogether. Probably don't want to do that with a gell cell unless the rate is C/20 or so. -- Eric F. Richards, "Nature abhors a vacuum tube." -- J. R. Pierce, Bell Labs, c. 1940 |
Reply |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
Amateur Radio Newsline(tm) Report 1420 - October 29, 2004 | Broadcasting | |||
Solar cell modules | Homebrew | |||
Solar cell modules | Homebrew | |||
More power questions | General | |||
Derivation of the Reflection Coefficient? | Antenna |