Forum: Solar and Generators and Alternate Power for Dummies Part 4

Wow! This is Part 4, continued from Part 3. Here!

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I need some input concerning reghargeable NiMH batteries. I have a decent supply of these stashed away as well as a couple of chargers (AC and solar). Neither of my chargers indicate when the batteries are fully charged. Am I not correct in stating that charging these batteries to less than their intended storage level can compromise the amount they can be charged in the future? Can you use a battery tester to determine when they are fully charged? Does taking them out of the charger and testing them cause a problem if they are not fully charged? How are those of you who are using the solar outdoor lights as chargers know when the batteries are topped up? This is not a major point I know, but if I really need these batteries I want them to last as long as possible.

HBB- Kind of runing between things, so this will be a little brief…

NiMH batteries are alot more forgiving of partial charge/discharge than were their NiCd cousins. but in the case of both of these battery technologies, the way the little solar chargers get away with the lack of control over charging time is to operate such that they charge the battery at a rate of C/10 or less. (C is the capacity in maH). Thus, if you had a 550 maH battery, and you charged it at 50 ma, it could tolerate a fair amount of overcharge without damage. In this case, the amount of charge current you need to apply is about 140% of the capacity (i.e., 55 ma for 14 hours would just fill it).

At higher charge rates, a sophisticated charger looks at certain variations in the terminal voltage of the battery to know it is full, and to stop forcing power into it before it explodes (Yes, they actually can explode if overcharged quickly). Also, the battery will rise in temperature sharply once it has achieved full charge, and some chargers look at the battery temp to determine when enough is enough.

Unfortunately, a NiMH battery does not change in terminal voltage very much until almost fully discharged, so you can’t really read it with a voltmeter as you can with a lead acid and divine some idea of state of charge.

To keep them happiest, longest, slight overcharging at C/10 or less is the best way to go.

Eccles to the rescue again!

1000 watt turbine, DIY, instructables

We could do the same for simple masks.

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A note to those who are planning some type of alternative energy source during SIP, you should test it out beforehand. Make sure you have all the connections, fuses, and replacement parts you might need.

I recently received my inverter and purchased some deep-cycle batteries and a charger. I have been trying it out to see how long I can run certain appliances before the battery reaches a level at which it should be recharged. The good news is everything works fine, the bad news is that power goes out of the batteries a LOT faster than it goes back in. You need to make sure now that you have all you need to power what you plan to use.

The best analogy is that batteries are energy buckets that you empty with a garden hose, but refill with a soda straw.

To Eccles our electronics guru, or any other experienced battery expert: I have read that once these deep cycle batteries are charged they should be recharged to top them off. I have found that if they are fully charged to a reading of 1275 with a few days they drop down to average charge 1225 or so, not exactly sure on this, but not a full charge. They are 115 amp hour deep cycle only batteries. Not starting combo.

Question, how do we maintain these so when the time comes we can top them off and keep them fully charged. Shoule we use them and draw them down to 10.5 v or just top them off?

NJ Jeeper- I’m not sure I fully understand the question. To have a battery that is ready to go at all times, one should trickle charge them, per manufacturers instructions. Usually that means leaving a charge voltage of 13.4–13.6 volts on them, which, ideally should maintain a charge current of .001C (where C is the amp-hour capacity of the battery).

Thus, for a 115 AH battery, once it is topped off and the charger finishes its cycle, they can be maintained at a current of about 110 millamps, which will keep them in the best possible shape, and ready to go when needed.

Hillbilly Bill – at 08:34

“The good news is everything works fine, the bad news is that power goes out of the batteries a LOT faster than it goes back in.”

I have similar experience but not sure how to measure what’s left in the batteries. I am supposed to check what’s left in the battery 15 minutes after the draw of power. While in use, the battery level indicator reads much lower than after stabilizing. Since I am not supposed to run the battery down too much, I have to be conservative. It would mean only sporadic use of battery power, and many hours of solar charging to get an hour of battery power. Yes, the ratio is skewed.

Reminds me of eating off a fruit tree.

Eccles, thanks. I am not using a trickle charger. Don’t have one yet, but alsot the charger I have says don’t charge without adequate ventilation. They are in and enclosed attached garage that is shut all the time. I was just going to charge them every 3 months. Should I trickle charge or do the 3 month thing. I have a fear of degrading the life of the batteries doing the 3 month refresh thing without drawing them down to 10.5 v with the draw of and electric heater. The memory thing about deep cycles. Do you know what I am trying to say?

ANON-YYZ – at 09:11: My inverter has guages on the front that measure battery voltage and also amps being used. With a little experimentation, I have found what battery voltage level corresponds to the battery being depleted to a 50% capacity. Of course this is not the most accurate measurement, but seeems to work well enough.

NJ Jeeper – at 09:38 I don’t think deep cycle batteries have the “memory” problem you are referring to. From what I have read and learned, they are happiest when kept constantly topped up. I would not use them just so you can recharge them. You only get so many discharge cycles out of each battery.

Thanks HBB. I will wave at you on Friday on our way to Htgn.

NJ Jeeper: Enjoy your time in the Mountain State. There are WV jokes on the humor thread.

Just to demonstrate the reality of Eccles “soda straw and garden hose” illustration, last night I used a deep-cycle battery and my inverter to power our main TV and DVR. DW and I watched TV for about an hour and a half and the inverter idled for about another hour. When I disconnected the battery and measured the battery capacity it was just below 50%. I put the charger on it and selected the middle setting of 12 amps, (If I use the 25 amp setting it boils the electrolyte). I checked the charging progress every hour and after 2 1/2 hours the battery was only back up to 77%. I went to bed at that point as the charger is automatic and goes down to maintain mode once the capacity is reached. I would think that it took another 1 1/2 hours to finish charging the battery. This is a real wake up call if you aren’t used to how all this stuff works.

HBB How many amp hours does your deep cycle battery have and any idea of the watts on your tv. I assume you were not using the DVR, so should not have had much drain.

The rating of the battery is 160 reserve amp hours. The TV, DVR and DVD player use a total of 225 watts. The inverter also draws 40 watts at idle. I was using the DVR because it also functions as the cable box. I know the inverter is actually to big to be powering just the TV, but I am still in the experimental stage with this equipment.

Guess I will use the 60 watt LED (17 draw) bulbs and the little black and white 5″ tv occasionally and the battery operated radio to maximize the deep cycle batteries. No big appliances at all just lights and maybe laptop once in a while.

NJ Jeeper: In times of extended power outages I will definitely be paring down what I will use also. The laptops use a lot less than the “main” computer and a smaller TV would be a savings. No matter how you figure it, the grid being down will be no picnic.

NJ Jeeper: 60 watt bulbs are still too much load (are you sure they’re LED?). A CFL bulb equal to a 60 watt draws about 15 watts. LED lights are great for task lighting (shining down on a table or workspace, or as a reading lamp).

Will, they are equivalent to 60w light output. But drwa about 15watt ±. Not sure of the exact numbers, since they are home. But anyway the drain will be much less with the flourescent low energy bulbs. Got them at home depot etc.

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Calling Dr. Eccles:

OK, pardon me for being so obtuse about this, but I am having trouble locating appropriate fuses and fuse blocks for connecing multiple batteries. In earlier postings, you (and others) stressed the importance of having a fuse in the positive leads between batteries, and also between the last positive terminal and the inverter.

My batteries are rated at 115 amps/160 reserve amps. If I remember correctly, the fuse size should be 1 1/2 times the capacity of the battery so I need a 240 amp, 12v fuse and a fuse block. Since I have been unable to find such an animal by myself either in person or online, I have resorted to asking at hardware and electric supply stores. Everybody looks at me like I am from Mars! Is this such a specialty item? I haven’t even found any information on any of the commercial solar sites I have visited. Any help will be greatly appreciated.

Sign me “Shuffling Battteries in WV”.

HB, I think that Kansas Windpower has what you need. On page 28 of their 2006 catalog they have listed Class T Fuse & Holder 200 amp, part #D028, for $45.00, and a Fuse Only 200 amp, part #D029, for $17.00. They also have fuses with holders, or fuses only, in 400 amp, 300 amp, and 110 amp. Find them on the net at www.kansaswindpower.net or contact at 13569 214th Rd, Holton, KS 66436–8138 USA or phone 785–364–4407. No interest in this company except as a satisfied customer.

HBB- In my own usage, I don’t size the fuse for the battery capacity, but rather to the maximum current I expect to draw, plus a margin factor. Thus, even though I may have a zillion amp-hour battery sitting on the floor, if I only expect to use it at the 10 amp level, and don’t allow the charging current to exceed 10 amps (as an example) then I would personally use a 15 amp fuse rather than a zillion amp fuse.

In my own usage, I have always found the sizes and ratings I needed at a full line supplier such as MCM (whose catalog lists an in-line holder for 4–8 AWG wire and up to a 160 amp fuse). There are certainly much larger fuses manufactured, such as shown Here in a manufacturers web site.

Perhaps one of our avid Large Solar systems guys can help out with the names of some of their favoriate suppliers of fuse equipment?

Just remember that the fuse must be rated for enough amps to allow for high initial charging currents, and also MOST IMPORTANT, be rated to be able to interrupt the current you are drawing at the voltage your are using. A good fuse spec sheet will show both the voltage rating and the current interrupting rating. If you use an inappropriate fuse, even with what appears to be a correct AMPS rating, it could well be unable to interrupt the power flowing through it, even though technically blown.

Ah! It looks like Kim dove in while I was still typing. I type slowly so people can follow what I am saying.

Sorry, Eccles, didn’t mean to steal your thunder:-) We bought our Vari-Cyclone 12vdc ceiling fan and fan controller for our cabin from Kansas Windpower, and found their customer service great and shipping fast (though sometimes a little hard to get through to on the phone, they must be busy folks!). They have a catalog ($4, or free with order) that has all KINDS of dc parts and gadgets that’s well worth the cost, and their website is packed with info as well.

Kim- No thunder required. Since you actually have a good source, then everyone benefits. Now if someone would just sell a small wind turbine for $49.95 I would be happy.

Eccles, ham radio question on the news thread, posted by analyst4markets

HillyBilly and others: I’m curious to know what type of system you have. I recently purchased a Xantrex 1500 watt inverter with a 40-watt solar panel. Have to pick it up today or tomorrow. I plan to use it to run smallish things like a laptop, a light or two, maybe a fan if it’s stifling. It is supposedly capable of running larger things in short bursts, but a solar guy I spoke to kind of discouraged me by saying that the 40 watt panel is going to be useless in a New England winter.

I plan to link several marine batteries to store as much as possible and to ration the use of the energy. I also plan to keep the solar panel connected to trickle charge while I’m drawing.

Any thoughts on this plan?

Edna,

Which New England landmark/city are you closest to? How long do you plan to run your laptop daily? What wattage bulb will you be using and for how long each day? This should be the starting point of the discussion.

Kim and Eccles: Thanks for the info! I’m sure I will be able to find what I need.

Edna Mode – at 10:06 Since you have already purchased a Xantrex inverter there is no purpose in describing what I have bought. My batteries are EverStart deep-cycle marine from Wally World.

My prepn advnture: Trying out the system in low desert 150 miles from home. The system: 1–50-watt Kyocera panel, 1 Costco/kirkland 85AH battery, 1 1500 watt Trace inverter, 1 $7 charge controller from Electronic Goldmine, sans instructions, 1 Boston Mountain charge controller with 3 pagees of single-spaced instructions. Simple hand tools, a voltmeter, wire nuts, roll of romex. The goal: run the chest freezer as a fridge for 3 days. Drag battery from back of car, attach inverter, plug in freezer, turn on and unpack the rest of car. About 4 hours later, the inverter low battery alarm goes off. Check battery: 11.3 volts. YAAAA. Unpack solar panel. Peer at connector uncertainly. No instructions? Strip romex with tin snips (long story), realize that the thing really needs lug terminals but I don’t have any, so wind the bare wire over the 2 terminals that I guess will make it a 12-volt panel in parallel rather than a 24-volt panel in series. Cross fingers. Get ladder, poke romex through hole in eaves and into house. Get out cheap controller. Dang, the worthless directions don’t say how to hook up the pot sos you can control the voltage. Oh well. Oops, will have to solder the romex to the terminals cause they don’t have binding posts. Have soldering iron but no electricity. Oops. Load stuff in car, drive over to Dad’s cabin and plug soldering iron into his outdoor outlet, locate his solder, and solder short lengths of romex to panel +, panel -, and control leads, hoping that the pot is +, -, and the center goes to thing marked ‘control’. Who needs instructions? Return to my cabin. In hooking it to the battery, I break off the - lead. Either go back to other cabin, or fix it here. Aha! the plumbing torch. Using spoon as heat shield, use butane torch to solder the romex back. Now that’s **some** kind of heat source. Hook to battery with wire nuts. Rig some strain relief. The green ‘charging’ light comes on, but the voltage isn’t as high as I thought it would be, only 12.3 volts. Run refrigerator 10 minutes on, 50 minutes off all day. It’s clear that 110 degrees is hard on the inverter, the refrigerator, and me. I cover the freezer with a wet beach towel, which brings the internal temperature down another 10 degrees. After most of the day, I decide to try the Boston Mountain controller. I rejigger the connectors, and hook it up. Despite pages of instructions, which binding posts go which way is not completely clear. Hey! the gen input is for the solar panel, lookie, the batt charging light is on. The out must be for the inverter…Yes. Much better charge controller, the batt voltage goes up. I run it all day, noting that as it gets hotter, the whole thing gets a bit ‘wobbly’, so I cut down the run time and lengthen the charge time. Did I mention going out and repositing the solar panel every 2 hours? And I couldn’t make the laptop work, the sinewave inverter whined about droopy power and the laptop sniffed with its little prima donna nose in the air about the heat.

Listen to Eccles, and check it all out in your driveway before driving 150 miles to see what you forgot.

wetDirt – at 16:11

Thanks for a laugh at the end of a boring work day! I could envision every step of your process. I have to applaud your ingenuity, but agree whole heartedly about checking your preps out before hand. Not only that, but buy extras of critical components. Just last night as I was falling asleep I thought about how all of my planning and expenditures would be dead in the water if my one and only battery charger failed.

Well, I nominate wetDirt for both the Try it in Advance of SIP poster boy, and the Red Green Silver Duct tape award.

I was actually cringing and writhing in my seat as I read this.

This also vindicates my obsessive/compulsive habit of ordering all of the Sale cables that MCM always buts into it Sale flyers. just this week I was setting up a DVD recorder and needed a particular cable which I had several of in stock. When I bought them, I didn’t have a clue when I would use them.

But you got the reefer running via solar power. A little shakey around the edges, but you passed the test. You’ll survive!

And for today’s Gold Star pinning:

Wet Dirt

For courage, persistence, and ‘git er done’ attitude.

So how much battery AH did you have left at the end of the day? How much more power would you project would be required to run the reefer at night? Would that require another solar panel in parallel?

I assumed that there was not enough power left for the night. Next time, I will take the Kill A Watt and measure it, and get better numbers. And I have a second battery, as well as a second panel, but didn’t want to hook them up after the ruckus with the first one. I ran the lights and everything else off the other battery. I’m not sure how to put the batteries in parallel, particularly if they have different levels of charge. I thought I might do that when both batteries were either empty or full. And I didn’t want to get out the second solar panel until I bought some conduit and put together a junction box. So the challenge was for one battery. Based on what I found, no sweat for spring, winter, and fall, but with excellent battery management, barely doable in the summer. And it’s not yet as hot as it gets, so I mighta spoke too soon.

Try to keep the battery cool in the desert, and keep the voltage from dropping below 12.3 volts or so.

Keeping the solar panels as cool as possible improves output, one reason to keep the panel on a pole where the breezes blow.

Will, that’s the impressivenest gold star I’ve ever seen. I’m nearly dumbstruck, lucky enough, my fingers can keep typing. Thanks. And thanks, Eccles, for the Red’n Green’n Silver Duct tape award, I will add them to my resume.

• pats self on back, relieved self still has all 10 fingers*

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wetDirt – at 23:29

I’m fairly certain that you could also qualify for the Redneck Shade Tree Mechanic certificate. To be a member, one must be able to swap an engine using only a metal tripod and “come-a-longs” as the lifting tools. The swap must be completed in the normal time it takes to consume a twelve pack of beer. If all of the leftover parts will fit in a 3lb coffee can you are inducted into the esteemed society.

I hope when you guys are all done what’s left is manageable by the other members of your family. No point in doing all this work, getting sick, and having it all go to waste.

Mari – at 08:48

Damned good point and believe me I have thought about that. Some time ago Dr. Eccles talked about writing out an instruction manual for his DW. I think this would be worthwhile for all of us to do. And not just male → female, it is needed both ways for those unfamiliar with the preparation of food and caring for the sick (I’m not stereotyping here, just making generalized comments).

Here’s the nasty part. I’m still getting around to it. It’s a praiseworthy idea, and will be necessary. I guess I’ll have to write fast as the fever ramps up and my vision blurs.

Or else, redefine my priorities and actually do the thing.

(Git ‘er done, as that great philosopher Larry the Cable Guy has observed).

Eccles – at 08:57

It is no small task to be sure, where to start? One idea is to keep those systems we are designing as simple as possible and use color coding or plain markings as to what is what. Sure, you know how to connect everything, but how can you communicate that?

A dear friend of mine had one of those free-standing outside coal and wood furnaces instaled that pumps hot water to heat your house. In the installation he also had a branch line installed to his workshop. To regulate the flow of heat between the two required the turning a valve that either sent more or less hot water to the house. If he wasn’t home, his wife had to either be too cold or too hot until he returned. He spray painted the valve bright red and marked WARMER on the wall on one side of the valve and COOLER on the other side. After showing her the valve and making sure she was able to turn it, the problem was solved.

HBB- The problem with being a “Deep Technoid” is that I have handled everything technical in the house, and DW hasn’t had to, and doesn’t wish to be bothered with those things. Even things like flushing the whole-house silt filter and changing the air handler filter are solely my responsibility. The computer and power systems of the house are my responsibility. The tractor and grounds maintenance (except the foliage near the house) are my responsibility.

Most of these things are now custom tweaked to my understanding and my physcial size. I think things like spray painting the critical valves with International Orange or some such is a very good idea.

Also, the idea of a manula for everything I do is daunting. But a folder for each item, such that the magnitude of the problem is reduced to small chunks. There is still the problem that things like rolling the generator out and plugging it in take physical strength and reach that she just plain don’t got.

Eccles – at 09:18 Good point, I have thought about that as well. My wife is 5′1″ and petite. Some things she can’t move or reach at all.

I kinda worry that if I actually wrote down instructions, they could be used against me, in court, at the sanity hearing. But my daughter has known since she was about 7 how to hook up an LED to a battery on a solderless breadborard. She had LED lights in a school project this year, the only one in the class who did. And she knows how to run the DVD player. So I’m sure she could work the solar charger, if I label things with the duct tape and a sharpie.

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The idea that a person ought to have a plan B charger is a good one. I just happened to notice that the March issue of QST (a HAM radio magazine) was in the bathroom, and it has a simple charger circuit. The April issue is the second part of the article. This charger looks like a good match to my small solar lashup. This is because the input current is limited by the power coming off the solar cells. 50 watts at 12 volts is four amps, for smaller values of 50. The Kirkland battery is 85 amp-hours. Looking at the circuit, I think I have all the parts except the big power transistor, and I might even have that. So with that, I will get off the computer and start building. If you see a column of smoke off to the west, it isn’t me, everyting is completely under control.

wetDirt- I you lack the transistors for the project, I have a couple of 35W4′s and 5U4GT’s that might serve suitably.

Thanks, Eccles, but I think this is gonna be a parts order thing anyway. After rummaging the parts bins, I came up with 6 TIP30s but no TIP42s, no 2N700s, 1 each of 32 flavors of opamps but no comparators, etc. etc. Piles of LEDs though. And no 1M pots, but tons of 50K pots. No zeners bigger than 5.1V. My collection is geared towards microcontroller apps, topping out at 5 volts and 20 mA. This 12V stuff is new territory. I suppose this means I shouldn’t build it into an Altoids can, either.

wetDirt-

Seriously, you can often use an op-amp in place of a comparator, especially if the circuit is not an actual digital construct. Or you can use a bunch of different CD4000 series gate chips as comparators. But if you want to follow the recipe in QST, then you should probably just send an order off to Digi-Key or Mouser and get the right stuff from the git-go.

Maybe I better stick to the script till my wings dry. Already, small parts fear me, and I have seen much magic smoke from them.

Once you have seen the smoke, the magic is gone. It is the magic smoke which contains the essence of chip. When you release the smoke, the essence is gone as well.

You speak truly, for you are certainly wise in the ways of the Chip. Yet, wise as you are, you might see less magic smoke than I, a mere acolyte. It seems passing strange that the wiser one becomes, the less magic smoke one sees.

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I used to like to come up behind people in electronics lab, just as they were about to power on their latest experiment. If I cupped my hands a certain way and gave a vigorous popping clap just as they flipped the power switch, the experimenter and all of the onlookers would normally jump about 3–6 inches, with various sudden movements, hair and glasses frequently akilter. For those experiements where the experimenter was hurried, taking shortcuts, and/or substituting components in a questionable manner, I could often get as much as 12 inches of ground clearance. It became my own form of geek behavioral olympics, though I had to be discrete about my noticeability aforehand and couldn’t do it too frequently (i.e., as in “going to the well once too often”)

Good old 723′s and a couple of 3055′s will make a great easy to build controller/charger with a very lower voltage loss. More fun to build your own switcher/controller and really get the most out of your panels. few ferrite cores and you get some real power going.

Will- For someone who is as skilled in the arts of survival and self preservation as you are, that behavior is remarkably risky. It may have resulted in your untimely demise in some of the venues that I used to inhabit.

Corky52-

For low to moderate power applications, my favorite trick is the old trusty 7812 series regulator. If you put a silicon diode in series with its ground reference lead, you get a 12.6 V source. Two diodes gets you 13.2 and 4 diodes gets you 14.4. A rotary switch gets you selectable charging voltages in 0.6 volts steps from 12.0 up to 14.4.

In a different configuration, you can use a 7805 as a series current controller.

Many thanks to Bob Pease at Nat. Semi., without whom the world would not be as neat a place to live.

Oooo, ooo, Eccles, I saw that trick once on a PIC project. I never woulda thought you could pull that off on serious grown-up stuff. So that was a Pease, then, was it?

Eccles, The 7812 tricks are constant voltage sources with current limits, nice but properly setup 723′s and 3055′s will give you constant current and then switch to constant voltage, bulk charging and then maintainer without having to monitor. Two 3055′s will give you the ability to handle 30 amps if heat sunk right. I’ve also seen 7812′s used as controllers for external devices to get high currents, just never built any.

Corky52, what do you think of this one:

http://www.electronics-lab.com/projects/power/032/index.html

wetDirt- I can’t say for absolute certain that this one is a Pease, but I have learned so many from him over the years that it is lumped into my head with all the rest of them.

Eccles wrote; > It may have resulted in your untimely demise in some of the venues that I used to inhabit.

The aforesaid lab was a school lab. And I really only did it to the ones who were a little nervous about their handiwork, component selection, or both. I normally had a few people clued in from a distance, so the chuckles immediately after were successful in keeping a positive outlook with the ‘jumpers’. One time (the first time, actually) resulted in magic smoke, so all I did was enhance the experience.

Will - The big “joke” at school when I was there was to charge up an electrolytice filter cap to 120V, bend the leads over parallel to the body on opposite sides of the cap, and then call out “Hey Will, Catch!” and flip it to the victim. They caught it, and immediately discharge the cap into their hand which caused a muscle spasm in the arm.

Great fun was had by all as long as the guy you flipped it to wasn’t bigger than you.

WD,

The setup on that kit will cut the supply off if current is exceeded, I’ll try and dig up a similar design that drops the voltage to hold the current under limits, better for charging batteries. Set max voltage and max current, then just leave alone!

wetDirt-

have you looked at This Kit as a possible controller for your project?

Interesting. One thing I wonder about, how available would the ICs be if there are no fab plants running? A couple look pretty standard, but the pMos and the main IC look a little exotic. I normally socket everything, it speeds up error correction, so it wouldn’t be any trouble to fix it if I could get the parts. But how exotic are these parts? THe QST circuit had just about the standardest parts around.

Usually, if I am worried about spares for something that I need, I also use sockets and then just order a tube of the parts from Mouser to fill out an order to meet minimum order requirements.

Most of the IC’s that i use are under a dollar, so half a dozen or a dozen extra are not a bank breaker.

Also, in any project I build which (a) handles power and (b) needs to keep running, I always make sure to have some spare chips on hand. You just never know.

Finally, If a project that does something like charges batteries needs a chip that costs $27.95, I use a different design. The cost/benefit ratio has to be pretty good before I’ll hack up big bucks for a mundane semi.

I’ve noticed this thread has drifted far into the electronic parts level, vice the component level (and vice the package system level). Would it be better to have separate threads for the detail crowd, versus those who want more general information about components and systems (or questions of sizing and applicability)?

Will- The drift is really due to a very slow time right now on this thread with few requests for explanations of larger questions. I don’t think we need to start a new thread.

If this chatter confuses things, I have set up a chat area on Yahoo groups that we can move some of this to. Especially if it is of little to no value for the general public.

Errm, ahh, Will, I can explain… On my part, it was deliberate, because after my shakedown cruise with Solar, I realized that the charge controller was a black box, and I wondered how to work around it if it failed. I had two, and only one of them seemed to work right. I guess if your plan is to ride out a few months, then not having a maintainable charge controller is no big deal, but if you think things could be bad for a long time, then being able to run the system for a long time becomes an important issue. So my questions over the last day have reflected my focusing down from the system to the parts to the bits and pieces—leading, I think, to a demonstration in the next couple weeks or so of an inexpensive, simple charge controller for a =small= system made of readily-available parts. The commercial controllers out there cost over $100, the kits over $50, the homebrew is looking like $20. So I think it will soon drift back.

Any experience with Yamaha or Coleman generators in the 2kW + range? I am ready to get the 2kW Honda. But thought I would check in with the experts first. This is for back up AC and backup charging of my solar set up that has a 255 ah battery.

MAV - My only extensive experience is with the Honda 5KW unit. I have never had any problems whatsoever with it except for a field mod which needed to be done to its GFI. When it is wired into a building’s electrical system, it is standing on the ground, and because there is a potential difference between the point it is standing and the building ground reference, it can trigger the GFI and shut the genny down. There is a quick field mod which needs to be applied if you are running a whole house with it.

But I am a very happy user of the Honda.

ok, the new Yamaha looks like it has taken sharp aim at the Honda market. Few differences. I think Im gonna go ahead with the Honda reliability. The Honda boasts “sine wave” out but nothing I can find has much detail on this so I am assuming it is some form of modified sine waveform. Not crittical for my app anyway. but I figured the mod SW would be easier on my rechargeable batteries.

wetDirt, I think discussing details like this is completely appropriate for those who understand this level of detail, though when the thread is labelled “for Dummies”, it implies just that.

Will- I think the name constitutes an invitation to visit and ask, and not a restriction on the breadth of the discussion the occurs. Otherwise, the details which Corky52 brought to us on the conversion of a chest freezer into a refrigerator would be equally as excessive, as would the details on solar construction which Solarsentry brought to the thread.

My own feeling is that whomever wishes to ask those of us here for help is welcome to, and if between times the discussion gets a little more technical, that’s OK, because someone who doesn’t know the specific details will still just start by asking for basic assistance with his/her own problem. Then all of us here know how to tailor the level of detail to the needs of the questioner.

Ok, back to the basics. As you know, I am looking for some power source. I have looked into generators (have a Generac 6500). I am looking for something when the gas runs out. I cannot put solar on the roof, as I do not have a southern facing roof. I have looked at other systems that only had a 40w panel and was advised that this system would not really work. I recently saw this set up with a 225w set up. I like the factr it folds up and would fit in the trunk of a car. link Any thoughts on this system? Again, I would like to run some lights, recharge a laptop and some AA, AAA, C and D batteries.

Worried-

This is a nice commercialized version of the kind of solar system we have been talking about for limited backup power. You should realize that this is just a “store-bought” assemblage of the same pieces we have discussed for any application, i.e. panels, batteries, charge controller and inverter.

I suspect that the cost will reflect the fact that they do the buying and assembling. There is still the issue of siting this syetm somewhere that it can get full sun all-day, every-day, without being molested or stolen.

As in any previous discussion, the first place to start is to determine what your power requirements are. Until you have an actual number you are working to, nothing else can be determined to any degree of certainty.

Eccles,

I need a commercialzed version, if I attempted to buy the parts, put it together I would end killing myself. What I am looking for is a system that I can store in an outdoor shed, when the SHTF, roll it out into a sunny spot in the back yard and charge the batteries. We have a relatively prvate yard. I would roll the system into the shed at night and lock it up.

I also, understand that I am starting at the wrong end and working backwards. My feeling is that I want to have the most power I can afford to obtain. I will then use only as much power as I have. Lights and the laptop. I can use the laptop to watch dvd’s with the kids, use the teaching / learning CD’s to teach the kids. I have stocked up on cheap CDs for elementary school children they are always on sale at Staples in the $1.99 bin. I would also want to charge batteries for LED lights.

From all of us who never owned a slide rule nor a pocket protector, thank you.

Doh! Doh! Doh!

I typed out a long reply to your question, and then hit the back button instead of the post button. DOH!

Anyhow, given that you are working from the store-bought system backward, lets see what you can do with it. The 225 watts of panel in NJ should give you about 800 watt-hours on a nice sunny day. A bit more if you go out every few hours to turn them to follow the sun all day. Since you can’t count on every day being productively sunny, lets make a conservative estimate and say that you can fully recharge every third day.

That gives you about 250 watt-hours per day to use. That much energy should be plenty for recharging the small batteries for the CD players, give you a couple of hours of laptop time plus recharge the batteries, and give you several hours at night with a couple of smllish compact fluorescent lamps.

I am very curious as to the selling price of the rig in the web site you referenced. I have my own idea of what they will charge, but I’d like to keep it to myself until you get the price directly from them.

«And by the way, I actually own a full Rubbermaid tub of sliderules. When the market for them collapsed, stores couldn’t GIVE them away, so they put them on sale for $0.50 to a couple of bucks. I bought every one I came across. Now they’re collectors items, and I have a squillion of them. I also still have a couple of brand new pocket protectors in the package, on my stationery shelf. I’m just waiting for them to come back into fahsion. Then I’ll strike!»

Eccles,

I worked my way backwards through Worried’s URL and found:

    * 80 Watt Solar Panel
    * Mobile Mounts for mounting panels directly to the system frame.
    * 104 Ahr Sealed
    * 750 watt AC Output
    * 1500 Watts AC Surge
    * True Sine Wave
    * 12 Amp Charge Controller with Two 12 VDC Lighter Sockets
    * Fits in the Trunk of Your Car
    * Plug and Play Operation

Price: $2249.95 Additional 80 watt panels 639.95.

‘Tis cute, but dang pricey!

bump

Worried in NJ:

I have a website page that I devote to answering common questions like yours about product recommendations. On that page is a 60W and 110W systems (sans battery) that are much less expensive than the system your are looking at. The 60W system should handle most of the needs you stated spring, fall, and summer, though might be a little short in the winter.

Another approach is to buy boxloads of books at library sales or yard sales and set them aside. Also consider buying home school materials off eBay or from someone in your community with children a year ahead of yours. That way, you won’t have a dire need for much power beyond a couple of Compact Fluorescent Lights (CFLs). Most of your other needs can be met with devices that have their own solar cells, such as LED flashlights, radios, LED lanterns.

P.S. Our kids found the books we set aside and are going through them like hotcakes. Time for another acquisition cycle…

Are one or more of you guys thinking of distilling all this great info into a main wiki page? I’d hate to be a newbie and have to scroll through all of these postings.

Mari- There is alot of information in Will’s book as well as some of the other links that have gone by over time in this thread.

Distilling this stuff down is a major task, and so it probably isn’t going to get done really soon. but I and others will still be here to answer individual questions as folks show up with them.

Mari – at 23:12

It is a work in progress. I promised Dem and lugon that I would cull (oops…perhaps not the best choice of terms!) the relevant info from past threads. I have some of the info saved, but some of it is unreachable now.

A lot of the basic information for alternative power solutions is available online, such as: Batteries and Chargers Kansas Wind Power Backwoods Solar Do’s and Dont’s

I’m not endorsing any of the commercial links, they are just some places I have been able to get information (mainly what I can’t afford).

And as Professor Eccles has said, he is available for personal consulting.

Professor Eccles, what kinds of solar system have you personally installed yourself and can you share those experiences with us? Thank you in advance.

Oh, sorry Professor Eccles, I wanted to get some clarity on this comment you made in an earlier post:

You wrote:

At higher charge rates, a sophisticated charger looks at certain variations in the terminal voltage of the battery to know it is full, and to stop forcing power into it before it explodes (Yes, they actually can explode if overcharged quickly). Also, the battery will rise in temperature sharply once it has achieved full charge, and some chargers look at the battery temp to determine when enough is enough.

Now, from what I understand, certain charge controllers have the option of performing a “equalization charge” which takes place “after” the battery bank (or a single battery) is “fully charged”, meaning it has performed most of the charging cycles and has gone into pwm charge. This equalization charge, usually at a higher charge, something around 15.5 volts, goes on for about 5 hours or more if cells are not of equal voltage. One would think, with your earlier post that this equalization charge…after the batteries are “full” with this forced overcharge would explode the batteries as you say. This exploding battery problem is something new to me. Can you explain what you mean more fully so that I understand? Don

Back in Part 3 of this thread, Np1 – at 14:12 said, “…nothing lasts forever.”

Well, I’m here to tell you that this thread does! Holy guacamole! I spent about four hours reading and taking notes on Parts 1 through 3 yesterday, and another 45 minutes today reading Part 4. My post is a long one, but I think it can be turned into a FAQ by the time we’re done for use on a wiki page now that I am ready (I think) to pose some halfway intelligent questions.

But before I do, let me nominate Will and Eccles as co-recipients of the “2006 Patience Is A Virtue Award” for all the TLC they have extended to people coming into the thread midway and asking questions that have already largely been answered.

With those formalities out of the way, here’s my situation:

LOCATION:

South Central New Hampshire

REQUIREMENTS:

1. Lights, 3 hours/day, 16 watts, total WH/day 48 2. Nebulizer, 1 hour/day, 287.5 watts (would only be used in event of illness from flu and would supersede all other requirements/desirements), total WH/day 287.5

DESIREMENTS:

1. Grain mill, 0.25 hours/day, 250 watts, total WH/day 62.5 2. Dell laptop, 2 hours/day, 90 watts max rated, but probably more like 18 as Will has pointed out, total WH/day 180 3. TV/DVD/VCR combo, 1 hour/day, 105 watts total, total WH/day 105

ENERGY SYSTEM ALREADY PURCHASED:

40 watt BP 340U solar panel and Xantrex XPower 1500 (including inverter, controller, 60 AH battery, cables, and cart for portability). Has two standard AC plugs and a DC power panel for 12 volt products. Solar panel rated power is 40 watts, rated current @ Pmax is 2.31 amps, nominal voltage is 12 volts, rated voltage @ Pmax is 17.3 volts.

MY UNDERSTANDING FROM PREVIOUS DISCUSSIONS:

Assuming the laptop actually draws 18 watts per hour (vs. max rated 90) and that I am not using the nebulizer, total watt hours/day for all requirements/desirements is 251.5 WH.

251.5 WH would consume approximately 35% of the energy stored in the 60 AH/720 WH battery that came with the system, which is within the 50% discharge recommendation.

To replenish the battery, I need to restore not only the 251.5 watts drawn but an additional (approximately) 25 watts for inverter inefficiency and 37 watts for charge losses bringing the total watt hours needed to fully replenish the battery to 313.50 WH.

Using the 40-watt panel included with the system, assuming 1) perfect conditions, 2) that reposition the portable panel every two hours, and 3) we are not drawing any power while recharging, it will take approximately 8 hours of ideal sunlight to fully replenish the battery.

SYSTEM SIZING QUESTIONS:

I think the system I have will cover my needs under general weather conditions spring, summer, and fall but will be soft in the winter. What size array (and incidentals like wiring, etc.) would you recommend I add to the above system to ensure my power needs are adequately met in winter months?

I would like to have back up batteries to get through at least a week of stormy weather. Using the 60 AH:720 WH ratio of the system I have, and assuming I use 251.5 WH/day, I need to store 1,760 WH or 146 AH, right? Do you think this is an excessive amount to store?

BATTERY QUESTIONS:

Assuming my week storage calculation is correct and I need to store 146 AH, what size, type, and manufacture battery would you recommend? I like to plan for worst case and hope for the best. I will take care of these batteries, and I want them to get me through the 12- to 18-month worst case scenario. I was told just to pick up a couple “deep cycle marine batteries at Sam’s for about $50,” but I have a feeling these probably aren’t the best choice. If they are, great, but I don’t mind spending a little more to ensure reliability and longevity.

I do not have any technical capability whatsoever when it comes to electricity nor does my DH. Should I link the backup batteries, or should I just plant to swap-out charged batteries for exhausted and over time replenish the backups?

If you recommend linking the backups, what should I ask for in re: the circuit breakers? The entire company (Sundance Solar, which is a lovely, local, small operation of good people) is overwhelmed by orders lately. The owner talks a mile a minute. I need to know what to say to him as concisely as possible to make sure he gives me something that I can hook up easily and use safely for the long-haul.

When I use my laptop now, I usually plug into the AC wall outlet so I can run off battery later. I usually get about two hours max charge on the battery for every couple of hours I’m plugged in. If I plug into the Xantrex inverter for a couple of hours, the same scenario would apply, right? I would end up netting four hours of usable power for the laptop, right?

APPLIANCE & PERSONAL SAFETY QUESTIONS:

Will I damage my laptop or other electronics if I use this system? I still don’t get the pure sine thing. I am buying a new laptop this week or next, and I really can’t afford to fry it. I plan to run it off the Xantrex before TEOTWAWKI to get used to quirks of Xantrex.

I was told by Sundance Solar that I can charge and use simultaneously. Some answers in this thread indicate this is not so. Please advise.

What is this talk about needing to store these batteries in a well-ventilated area? I saw a couple of passing references to this in the thread, but never any response. What’s the danger? How should I manage these batteries to ensure my family’s safety?

Thank you all, and especially Eccles and Will, for your gracious help.

Edna, Never store batteries inside your “living area” without some kind of ventilation as these batteries produce highly explosive hydrogen gas. (and will do so, especially when in equalize cycle) You could however, build a box to contain your batteries and install a special exhaust fan to remove the hydrogen gas from the box to the outdoors. I would never store batteries indoors. However, the downside to storing them outside is to prevent them from freezing and the laws of physics say that the colder a battery gets, the harder it is to charge and the less capacity it has overall. And you should Never…charge a frozen battery. Also, it is wise to install your batteries away from any electronic components as the hydrogen gas tends to denigrate them. Look at this: http://www.kyocerasolar.com/solar/batteries.html Look at this too: http://www.ka9q.net/pv/

Edna Mode – at 15:07

And I nominate you for the “Perseverance is a Virtue” award for doing the research necessary to ask intelligent questions!

I will not attempt to answer all of your questions, I will leave that for Eccles and perhaps Will. If you don’t mind, I will respond to what I do know about and also share what I am doing.

So far I have purchased 3 deep-cycle Marine batteries from Walmart. They are Everstart brand, rated at 115Ah/160Ah reserve. I bought these because I can afford them, I’m sure there are better choices, but this is what I will have to go with.

I have found that one battery will not last as long as I thought. My original plan was to just keep switching batteres also, but now I am going to link the 3 batteries in a bank and in the future purchase 3 additional to form another bank. In some situations it only makes sense to charge as you use, but in my applications I will either be using or charging the battery bank.

Cables to link the batteries are readily available from auto parts stores. Keep the length to a minimum and use 4 guage cables. Be very careful anytime you are working with the batteries! There should be a fuse installed one the positive lead between the battery bank and the inverter. I got mine from Kansas Wind Power. They were very helpful once I got through on the phone (no online orders).

Adequate ventilation is important during charging because hydrogen and oxygen gases are produced during this operation. If these gases collect in sufficent quantities, any spark can set off an explosion. My battery charger recommends attaching at least a 24″ cable to the negative terminal of the battery so that any sparks during connection are away from the immediate vicinity of the battery.

I hope this is of some help.

DISCLAIMER: I’m still on a learning curve with all of this. For those of you more knowledgeable, if I have posted in error, please correct me gently.

HBB,

I only have one comment and thats about the 4 gauge battery interconnect cables. In my opinion, the size of those cables depends on the amperage which the inverter will be drawing at its maximum. I have 0/2 gage on my system and all cables, those between the batteries and those to the inverter are the same size and I keep the cable from the batteries to the inverter at an absolute minimum.

Photondon – at 15:45

Thank you, you are absolutely right. It is easy to think just of one’s own application when posting.

An additional note, I also bought a second, smaller battery charger to keep the batteries topped up. My main charger is automatic and goes to “float” once the bateries are charged, but I don’t want to leave it running all the time.

Thanks HBB and Photondon! I’m taking notes, digesting, and will have more questions I’m sure! I’m hoping to hear from Eccles and/or Will in the next day or so and will consolidate questions at that point so I don’t confuse matters too much.

HBB,

Having been in the vicinity of a battery explosion (starting a stranger’s frozen car in Minnesota is part of “Minnesota Nice”) I can tell everyone that you REALLY, REALLY want to avoid this.

Photondon- Sorry I’ve been away all day and am in between other tasks, but I just wanted to answer your question about the sophisticated charger and ceasing of forcing power before the battery explodes. That answer was specifically in reference to a quaestion above it regarding the charging of NiMH batteries. Different battery technology altogether from lead-Acid. Sorry if the answer generated any confusion.

Melanie:

The instructions with my battery charger seemed excessively strict to me so I checked with Eccles. He confirmed that any chance of a spark should be kept the he** away from the batteries. That was all I needed to hear.

HillBilly Bill – at 21:53 - Yep! as Photondon – at 15:24 stated, “these batteries produce highly explosive hydrogen gas”.

Think “Hindenburg”!

BTW, I’m starting to suspect that Photodon has a bit of expertise in this area, a knack for writing, and may nicely supplement the information that we’ve relied upon from Eccles, Will, and others. Welcome aboard, Photodon! I’ll look forward to more of your posts.

Edna,

You get a gold star for doing your homework so thoroughly.

Following the process and calculations laid out in my book online here, let’s start with your needs;

1. Mandatory: 13 watt light bulb = 50 W-hr/day (rounded)
2. Crucial: Nebulizer = 300 W-hrs/day (rounded)
3. Desired: Subtotal = 65+40+105=210 W-hrs/day
   1. Grain mill: 65 W-hrs/day
   2. Laptop: 40 W-hrs/day
   3. TV/DVD/VCR: 105 W-hrs/day

Next let’s look at the potential solar energy in your area; http://rredc.nrel.gov/solar/old_data/nsrdb/redbook/atlas/ For south central New Hampshire with a Flat Plate Collector Tilted South at Latitude + 15 Degrees

Your solar panel will produce;

Summer peak: 40W * 5.5 hours = 220 W-hrs/day Winter minimum: 40W * 3.3 = 132 W-hrs/day

If we subtract out 15% for DC/AC conversion, 5% for wire/fuse/terminal/etc losses, 20% for charging/discharging losses, you can expect the following energy to be available from your batteries daily;

Your system will meet your stated lighting needs year round, along with;

• 1.5 hours of laptop use in the winter
• 2 hours of laptop use in the summer, plus about 10 minutes with your electric grain mill. And since you will need lighting less in the summer, there would be more power available.

Your 40W solar panel would not be enough to run a nebulizer in any season. You would need 2 more panels minimum for summer use and 3 more for winter use.

If you plan to use 132 W-hrs/day, you will need, at a minimum, a battery that will store twice that much IF you need that energy when the sun is down, so that you will not exceed 50% Depth of Discharge (DoD). 264 W-hrs translates to a minimum of 22 Amp-hours with a 12 Volt battery. However, note that most batteries are rated at a 20 discharge rate, which is easiest for the battery to perform. If discharged at a 3 hour rate, the amperage rating could be as low as 75% of the 20 hour rating.

22Ah / 0.75 = 30 Ah/day

Your current battery will more than suffice for daily operation.

For a week’s worth of the same energy;

30 Ah/day * 7 days/week = 210 Ah/week

This would require either a large battery, or two medium sized batteries, such as ]] http://www.trojanbattery.com/Products/ProductSpec.aspx?Name=27TMH|Trojan 27TMH]]

However, if you run your main electrical loads during the day primarily with panel power, interspersed to allow some recharging in between uses, then your current 60AH battery will be sufficient. I would assume you wouldn’t be on your laptop while running the grain mill or watching TV. Just be cognizant of the number of cycles you would be subjecting the battery to.

Some points to consider for reducing the energy load further (for others who have not yet made similar purchase yet);

• Instead of TV, use a solar/crank powered radio to listen to news and music. Store up several dozen used books.
• Instead of an electric grain mill, use a hand powered one, such as the reasonably priced, non-strenuous Family Grain Mill.
• For lighting, consider a solar powered LED lantern.

With these measures, one would not require a PV system (assuming no other mandatory electrical needs). Conversely, this might also be the impetus for some to make the jump to solar powering their home, assuming they have energy efficient appliance.

Edna Mode- Sorry for only giving brief answers to individual questions, but I am very distracted today by other than the Wikie. I just wanted to make one comment about batteries indoors.

There are several battery designs that are intended for safe® indoor use, and these are the SLA (sealed lead-acid) and AGM (Absorbed Glass Mat) battery. they are designed to contain and re-absorb gasses produced during charging As Long as Manufacturers Charging Recommendations Are Followed.

With these batteries, one MAy NOT do an equalizing charge, and it is important to obey charging voltages carefully. For instance, one manufacturer limits charging voltage to not more than 14.1 volts for safe indoor use (I think this one if from East Penn. I’m working from memory here, so if I’m wrong, I apologize). By the way, I think if you’ll check, the Xantrex unit uses an AGM battery.

The implications to this are that one must be sure the charger one is using with them is matched to the specific battery class to insure that charging guidleines are adhered to. This includes the charge controller. A charge controller which is suitable for Deep Cycle or Golf Cart batteries may be inappropriate for thee batteries in indoor service.

When I get some time, I’ll try to get a link to the East Penn site, whi8ch has some good info about the differences in care for their SLA and AGM vs ordinary lead-acid designs.

Melanie- Did all of your clothing disintegrate one or two washings later?

Will & Eccles: Thank you for your answers (and the gold star!). As I mentioned to HBB, I will take the information, digest, and let you know if I have further questions.

Eccles: I appreciate you have other demands on your time, and I will welcome any information you are able to post later on.

Will, you are right that we would not attempt to run multiple appliances concurrently. We will be very judicious about rationing.

As for reducing power requirements, I have built in redundancy to my plans, so, for example, I already have two manual grain mills (each performs well at different tasks), and I have tons of non-electric diversions and activities planned for homeschooling and entertainment. To say nothing of the fact that simply existing without power will keep us much busier than normal.

I am going to look into the non-strenuous family grain mill you mentioned, Will, as the two I have are decidedly NOT non-strenous. That’s why I was thinking it would be worth the 62.5 WH to use my KitchenAid. I may sell them on eBay and replace with the family grain mill you mention.

(Sidenote: Will, I think you said your children had found your book stash so it is time to replenish. I recommend eBay. We spend altogether “too much” money on books in our house, and I only wish I had thought of eBay sooner. I purchased two huge lots of Newbery Award-winning books for our family to enjoy (we often read aloud together) when we are without power paying between $0.75–1.00 per book. New, these books would have cost about five to ten times that. “Too much” is in scare quotes because, as writer, editor, and voracious reader, I don’t think you can ever spend too much money on books!)

If power is out on any scale, my freelance business income stream will probably dry up for the short-term. I am planning on using the laptop for more morale boosting type activities. My son and daughter both use the computer for some enrichment activities and games. And family movie time is a big tradition in our family where we all pile together, snuggle, eat popcorn, and watch a movie. I think it will be important to try to maintain some sense of normalcy throughout our SIP, and that’s one way to do it.

Thanks, and I’ll be back with follow-up questions later I’m sure!

Edna,

See the grain mill comparison table for information on cost, energy input, flour fineness, and other metrics. The Family Grain Mill has very low torque requirements and gets the job done fast, so much less huffing and puffing.

I’ll look into eBay for the books, though yardsales and library sales are also great deals here.

We have movie time too, but also play games for our family time (Sorry, Chinese Checkers, etc).

Edna- Another place to look for good books cheap, and at low cost is Goodwill. My DW often brings home piles of books for 25 cents a piece, some of them have never even been opened.

Edna Mode – at 10:13 “And family movie time is a big tradition in our family where we all pile together, snuggle, eat popcorn, and watch a movie. I think it will be important to try to maintain some sense of normalcy throughout our SIP, and that’s one way to do it.”

Exactly the reason for my inverter purchase and the assemblage of a battery bank. I could just run essential items with a generator, but I feel it is neccessary to keep at least some sense of a “normal” life. Along the same lines I have also made arrangements to be able to have spaghetti once a week for many months.

I just ordered 2 Audio compact quick chargers for AA or AAA batteries and 2 sets of Ni-MH 4-pack AA batteries (looks like 2100 mah) from the clearance pages of Solutions catalog, $8.90 each piece or pack. I hope it’s a good deal. My question is, should I leave the batteries in their packs until needed (WTSHTF and we still have power) or charge them and start tending them now? If I understood earlier lessons, a rechargeable battery has a limited number of cycles, and Ni-MH batteries won’t keep a charge if left in a drawer until needed, so my inclination is to store them in their wrappings. Thanks! (It isn’t a final sale, so if you know the product is junk, please tell me.)

 SolutionsCatalog.com

Jane- My apologies for taking a while to get to you, and for the brevity of this response, as I am between other tasks today.

In my own usage of NiMH batteries, I leave them uncharged in their original packaging for up to about a year. It is my own impression that they keep better that way if they are not going to be put into active service immediately.

With both NiMH and NiCd batteries, I have found that even if left new and uncharged, after about a year they begin to slowly degrade. I have had some in storage for about 3 years, which, when I tried to charge them using a normal smart charger, they were rejected as bad. I was subsequently able to revive them using some lab power supplies and after that they were fine. this is not something I would recommend the average person attempt.

So my answer would be to keep them uncharged for up to a year, and then you should really charge them and start to cycle them periodically.

Realize that cycling or not, they then have a finite lifetime of as much as 3 years, and then done. It’s kind of like the common cold. If you treat it, it takes a week and a half to 2 weeks. If you treat it, it is gone in 10 to 14 days. Much the same with rechargeable batteries. In my 30+ years of experience in using and maintaining rechargeables, you can shorten their lives by abusing them, but if you treat them really nice you can get about 300–500 cycles out of them, or about 3 years.

Thanks, Eccles - I really appreciate your tutoring!

Eccles and Will: Thanks bunches for the info. I think the only question that I am still uncertain on is this: Is the system I have actually safe for my electronics, or is there something I should do to protect them to prevent destruction by the inverter.

Also, another fabulous place to find inexpensive books is the library basement sales. I have found so many treasures there for so little money! And it’s fun to rummage.

Edna Mode – at 14:15

Does your inverter produce pure sine wave power? If so, no worries.

Edna Mode- Such a simple question. Such a horrendous problem to answer.

The definitve answer to your question is, It Depends.

There are so many variable to the answer, that only by actually trying stuff out and seeing whether it kills your equipment can the answer be known for sure. Here’s why:

There are basically two type of inverters out there that you will encounter (1) True Sine Wave and (2) Modified Sine Wave. At the same time, there are two type of internal power supplies within your equipment that consumes power (A) Analog and (B) switch mode.

Now lets see how these all interact. Most of the cheaper inverters out there, as well as many of the expensive ones produce an output which the manufacturers call “Modified sine wave”. For the purpose of a lay-person, if a sine wave sounds like a pure note (like a flute), the modified sine wave version of the same note would sound somewhere between a kazoo and a Bronx Cheer. That is because it is much easier (read cheaper) to produce an inverter that produces the modified sine wave.

This then brings us to the two types of power supplies that your equipment can contain. Most older equipment (and some modern equipment) contains what is called an analog power supply. This is designed assuming that it will be fed a pure sine wave. If it is fed the output of a “modified sine wave” inverter, it can either have trouble producing the correct output voltage, or else electronic noise can passs through it as well as the intended clean power. This has the potential of damaging sensitive components wihtin the device that it is powering. Or at least making things look or sound odd when you use the equipment.

Newer equipment uses something called a “switch mode” power supply. this is much happier swilling down whatever kind of power you hand it and can produce the correct output from it. With internationalization of equipment manufacturing, many switch mode supplies these days can actually run on anything between 80 and 240 volts between 50 and 60 Hz. But some switch mode supplies will still pass along some of the nasty stuff that comes from a “modified sine wave” inverter. Others not.

Now to try to sort things out. Some devices just plain don’t care. Old fashioned light bulbs don’t care. Most compact fluorescent lamps don’t care (switch mode ballast). Most modern computers use switch mode supplies and don’t care, which is why the cheap UPS units can get away with the junk that they put out and call power. Most laptop power bricks are switch mode supplies and can take the output from a modified sine inverter.

Much entertainment equipment is pretty sensitive to power purity. I have a high quality amplifier that hums audibly when it gets fed power from my generator, which is much cleaner than what a modified sine wave inverter puts out. I’d never feed it output from a cheap inverter.

Some microwave ovens do not do well on inverter power. There are actually microwaves marketted as safe for use with inverters.

And so, that’s why It Depends. It depends on which inverter you are using, and what you are trying to feed with it. Hillbilly Bill has gotten a Pure Sine Wave inverter to make sure that this nonsense doesn’t happen over at his place. I do not yet own a large pure sine wave inverter, but it is on the list of things I’ll be buying with my next installment of spare change.

I hope this helps. It probably just makes things worse.

Come back with additional questions and I’ll try to clarify whatever points need clarifying.

Eccles:

In an earlier discussion you stated that you would size the fuse on the positive lead of a battery bank to the amount of power being drawn from the inverter. Would this also apply to the wiring connecting the batteries in the bank? For instance, if the load was light, would 4 guage wire be of any advantage over the heavier 2 guage wire, or should a heavy wire always be used? I have been unable to find any clear guidelines about this.

Hillbilly Bill- In any high current application, the heavier the wire, the less the power losses within the system will be. A heavier conductor has lower resistance per foot than a lighter conductor. Since the power lost due to heating of the conductor equaly the current squared multiplied by the ohmic resistance of the conductor (assuing DC conditions) then you really want to keep the resistance of the cabling as low as possible.

Since 4 gauge has a resistivity of .00025 ohms-per-foot, whereas 2 gauge has a resistivity of .00016 ohms per foot, there will be a somewhat lower power loss due to cabling when you use the heavier gauge. Also, if one were to follow strict engineering practice, 4 gauge should only be used in applications in which current does not exceed 60 amps versus 90 amps for #2 gauge.

Bummer, bummer. I just called Sundance Solar and asked. I have a modified sine wave inverter. Sooo…I have 30 days to return this system. I paid $759 for it. Here are my questions at this point in the game:

1. I need a plug & play system. I have too many other new skills to master to add wiring to the list. Is there a comparable plug & play out there with a 40- to 60-watt panel and 1500 watt *pure sine wave* inverter for $750–1,250 that is reliable and recommended?

2. HBB: Eccles mentioned your pure sine wave inverter. May I ask what you have and where you bought it?

Muchas gracias, all!

Edna Mode – at 15:29

I bought my inverter from…believe it or not…Inverters ‘R Us. Here is the one I bought. I am really pleased with it, it is DEFINITELY heavy duty.

As far as plug ‘n play goes, all you need is an inverter and a battery (or batteries). From your earlier posts, it sounds like a decent deep-cycle battery would fit your needs. You could buy two and charge one while using the other.

Eccles – at 15:28

OK, now I’m really not understanding. In consultation with the salesman at Kansas Wind Power, he said that the fuse they recommended for the Xantrex 1500 Inverter was a 200 amp Class T, so that is what he sold me (along with the fuse block to hold it). Now, the guage on the front of my inverter, (amps out), starts at about 50 and goes up to over 200. If even 2 guage wire should only carry up to 90 amps, do I need even heavier wiring?

I purchased the following 60W solar system from Connecticut Solar. It is “plug and play” but does not come with a pure sine wave inverter. I was, however, able to power our nebulizer off the solar gel battery that is included with the system easily. I have purchased two additional solar gel 50ah 12V batteries to add to this system to build up power reserves. The thing I like most about this system is how compact it is (it fits in a backpack) because the panels fold.

http://www.ctsolar.com/Expedition%20Power%20Packages.htm

Hillbilly Bill- the key phrase was “Strict Engineering Practice”. This means if you are designing a system to be built into something else and then go through Armagedon and back, then those are the limits you should obey.

In actuality, those wires can handle about twice the load safely. Thus, something like 120 amps for #4 ga. and 180 amps for #2 ga. is the practical maximum that the wire itself can actually handle. Since this is an impromptu system, and is in the open air (more cooling) then I wouldn’t worry.

If you want to delve into this deply, then I would google the term amapcity and cable or wire. Also, since the ampacity (current capacity) of a given conductor is defined by the National Electical Code depending upon whether it is bundled with other cables or has more air circulation around it, then you would need to look into your own application if it is to be NEC compliant and be a permanent installation.

It’s only if you are building tanks, spacecraft or the Lost hatch, or meet a building code that you need to follow those numbers. (Which leads to the question, was the Hatch ever signed off by any kind of building inspector?)

Edna Mode- If you have already demonstrated to your satisfaction that you can run lights and nebulizer off of the Xantrex, then why think about returning it? It already meets your baseline requirement. I suspect that your laptop will also be fine running from it, especially if you plug a 12V supply into the battery out port of the Xantrex.

For anything else, like eentertainment gear than you are concerned about, you can get a much smaller Sine wave inverter and pull the power from the 12V port of the Xantrex.

no need to pitch the whole system.

Eccles, Will, HBB, and others: Thank you all so much. I feel reassured that I now understand what I need for my family’s purposes. You have all provided much support, and I really appreciate it. You can rest assured that I will recall this exchange with gratitude when I am using my system.

I have run #00 from my batteries to my 3600 watt sinewave inverter. It is hard to work with and takes special crimpers or sodiering for end connecters. I run three full desktop computers, microwave, lights, stereo ect, many at the same time. Occausionally I pop the breaker on the inveryer(overload) but I hardly ever get the wires warm! Kelly

Inverter, inverter! I need a spell checker. Kelly

NP1- I thought you were just using the Norwegian spelling.

Edna Mode - Glad that our efforts here have been of benefit to you. Hopefully, others have been helped as well along the way.

Np1 – at 17:15

I’m sure that size wire is not fun to work with at all. Also, I know I don’t have anything that will cut it. Well, let me correct that statement, I know I don’t have any thing that is NORMALLY used to cut wire that will cut it.

I like the idea of using the pre-made cables, they are quite easy to attach.

Eccles – at 16:28

As always, thanks much for the excellent advice. I will proceed with cation as to loads on the inverter and check the wiring often to make sure it is still within safety limits.

Just who would sign off on the Hatch? Despite the generic supplies, I’m not sure it’s a government project.

Edna: It’s our pleasure, really. I suggest you try your system out for a few days running, to make sure you can maintain 50% battery reserve.

HB: Pre-made cables with terminals are indeed heaven-sent for those who do not do this frequently, especially if someone is using multiple batteries.

Will: Thats for sure, especially since my batteies have both the top post and a bolt and wingnut connection also on the top.

HB wrote: “it sounds like a decent deep-cycle battery would fit your needs. You could buy two and charge one while using the other.”

It is far easier, more flexible, and easier on one’s batteries to connect them in parallel and charge (or discharge) them simultaneously (unless one’s charger/inverter combination precludes this). You are less likely to drain a battery down too far, or miss important charging time.

Hi folks. I’m back with another couple of questions on generators this time.

Since gaining a greater understanding of solar limitations, I have been seriously mulling the idea of getting a generator. I am only considering this as a means to ensure the well pump is usable a couple times a week to fill containers.

Here are my concerns:

1. Money: Between the cost of a quiet, fuel-efficient generator, getting it wired into the circuit, and stockpiling the gas, I’m estimating anywhere between $1,500–2,500. It would be a significant expense that we really can’t swing but could put on (gag) plastic.

2. Noise as thug pheromone: I would ideally swing for a quiet generator that we could keep in our garage (using direct-vent), but I don’t want to be a target. My philosophy is to keep a low, low profile during pandemic. I don’t know how consistent a generator is with that philosophy.

I figured out last night that between filling tubs, pools, and water barrels, we have approximately 725 gallon storage capacity. The pool and water barrels are going to be tricky if maintaining through freezing weather. We also are setting up a rain barrel and have year-round access to running surface water in our marsh. Plus, we have a British Berkey filter and means to pasteurize virus-laden water.

725 gallons is enough to get our family and dog through approximately four months of SIP at 1 gal./day. During freezing months, we would still have access to marsh water and snowmelt/rain collection.

Questions:

1. Is anyone here working on the assumption that the power grid will be down *consistently* for stretches exceeding four months?

2. Should I spring for the generator and related expenses given my access to surface water, rain barrel, filters, etc., or should I put that money into more grains/legumes (We have about 5 months of food stored and year-round gardening capacity using cold frames)?

3. Does anyone know a good generator comparison resource similar to Walton Feed’s grain mill comparison chart?

Thanks all!

Edna Mode – at 10:44

Again, I won’t try to answer all of your questions, but will comment on what I do know and what I plan to do.

Some fluwikians may be anticipating that essential services are down for more than a few months, but short of owning a set-up like the “Hatch” on “Lost”, I don’t know how one would prepare for such an event. My own worst case scenario, is to be able to provide a little bit of electriciy for my home each day for a TOTAL of 3 months. It would certainly be wonderful if I didn’t have to do all 3 months at a stretch. In other words, I’m hoping for temporary outages and rolling blackouts, rather than a complete cessation of service. I’ve said it many times that if the power is off for more than 3 months, then something really bad is broken (infrastructure), and all bets are off at that point. That is more than I can prepare for and so therefore I just have to pray it doesn’t happen.

If you are talking about gasoline powered generators, than Honda is a very good brand. Dependability is what you are looking for and they have an excellent track record. We have a generator that we use on the farm, but it has a lot of hours on it so I plan to get another one this fall. I am planning to buy a Coleman 5000/6250 model. I like the looks of this unti, it meets my needs, the engine is made by Subaru which is a company I have great faith in, and mainly I can afford this model ($600) and it is in stock at Lowes.

Having a transfer panel installed and wiring your generator into it so that you can run specific circuits is the best way to go. However, you don’t have to go that route if you can’t afford it. You can always do the extension cord method which is what I will be doing.

HBB: Thanks, as always, for the good answers. Unfortunately, I don’t think I have the option of using the extension cord with my well pump (which is all I really care about running off a generator). The pump is wired directly into a little gray box at the base of my holding tank that says “Pumptrol” on it. No actual plug anywhere. If there’s something I’m missing, please let me know.

For what it’s worth, I am hoping and believe (perhaps delusionally) that we will have intermittent power service. Maybe not for long, but I can fill a lot of holding containers in a couple of hours. My plan is that as soon as power comes on at any point in the game, I drop what I’m doing and fill, fill, fill.

So am I right, HBB, in saying you would NOT get a generator if you had access to four month’s of water storage?

Edna Mode – at 16:46

I would want a generator on hand, if just for the fact that it comes in handy for “regular” emergencies. We have power outages from severe thunderstorms, snow and ice storms, and good ‘ole boys hitting telephone poles on the weekends.

I’ve got 4 months of water stored, but I want to have occassional power also.

Edna Mode- That little box marked “Pumptrol” is the demand pressure regulator. It senses the pressure in the holding tank and send power to the pump when it gets low, and then turns off the pump when it gets high enough.

In my own case, it is wired directly back to the main fuse panel. I suppose if you had a small enough well pump, it COULD be plugged into an outlet, but if you see wiring coming out of it and heading in the direction of somewhere else, I would assume it wires directly back to the panel.

if you check the panel you will probably find a pair of fuses which control the pump, which means it runs on 240V. if it is a single fuse it is 120V.

in my own home, I had a transfer panel installed which permits the power which feeds the breakers for the pump (and other things) to be selected to come either from the mains, or from the umbilical in back of the house (or the one in the front of the house also).

(Yes Bill, two umbilicals, no waiting.)

Gee, Eccles, you must be older than I am. Nobody uses fuses anymore. LOL

AVanarts-

I really don’t use that many fuses. The pennies have done very well all these years, and I’m not about to change now!

(Actually, breakers is what I have. I guess I must have been losing my most recent memories as the Oldzhtimers Syndrome takes over).

Since I have two wind-up Victorolas my entertainment needs are all met, even if I blow one more fuse than I have in stock.

bump

Edna;

Q1: I don’t expect power to be completely off for 4 months at a time, though I do believe that in some grid control areas it may be out repeatedly for weeks at a time. That is a long discussion that is partially addressed in the latest version of my book.

Q2: With your access to other water supplies (assuming you will purify any water that needs purification), then you are astute to recognize that a generator can be an expensive, non-essential item.

Q3: I don’t know of a comparison between generators. You might try a Google search with the name of the generator and the words “problem”, “issue”, “evaluation” if you are still interested in them.

Eccles – at 22:08 Wow Professor, I really am impressed! If you have so many redundant systems in your house, how come there isn’t another Eccles unit waiting to be activated?

AVanarts – at 22:27 Fuses are alive an well in my house. I’ve got those big honking 60 amp babies. The only breakers present are in the sub-boxes I have installed.

Eccles:

I’m pretty sure I know the answer to this question, but I will ask it on the forum for the possible benefit of others.

Larry the Cable guy grounded the cable box to the support frame of my gas pipe where it comes up out of the ground. This would be an easy reach for grounding my inverter, the actual ground for the electrical system is farther away. Would I be safe using the gas support frame?

Sign me “Not looking for fireworks in WV”

HBB- I’ll back away from this question. SInce I am not aware of the issues involved with grounding to a gas pipe, I really would recommend cnsulting someone who is licensed to do electrical installations in WV. Also, there is a difference between a cable service attachment and your inverter, and that is the magnitude of the power being potentially shunted through the pipe in the event of a component failure.

Lets keep fireworks outside the house, and only on the 4th.

«And I tried to activate the spare Eccles unit. But he kept trying to deactivate ME.»

Eccles – at 10:20

Well, even though it will take more wire, I’ll go to the ground at the electrical input. More than likey LTCG took the easy way out.

I definitely had sweaty palms when I was connecting the batteries even though I was standing on a rubber mat and being careful not to touch anything that could ground me.

Another interesting note, my super-duper, all-inclusive, automatic sensor battery charger plugged away valiantly for awhile to bring all of the batteries up to full charge, but then got confused and shut itself down. The cheapy 1.5 amp unit is working fine even though the manual that came with it said that it could possibly shut off if connected to batteries in paralell. Go figure.

HBB, how many batteries do you have hooked together?

Three. They are Everstart deep-cycle marine, 115a/160a reserve.

Closed due to length. Conversation is continued in Part 5 here.