nothing lasts very long and vehicle batteries are easier to find in bad circumstances and will suffice for some basic help while adapting to coming times when the sun, seasonal precipitation and warrior skills will be only support our saved seed will have.
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Hereâs my take on things now that COVID is over.
The next 2 agenda items are being run simultaneously, because they go hand in hand. They are energy and food.
Oil and gas in short supply cripples food. What did they do to ensure there was a short supply and where will it hit the hardest? My guess is thatâs Russia. And all the sanctions will be by design, the people of the West will even be likely âforâ these so there are no Trucker type protestsâŠitâs all fine until itâs not.
Feels like it is all by design. Feels very deliberate to me.
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During a longer term outage of electricity, dry ice can be used temporarily. Dry Ice is super cold and fairly compact. Unfortunately you cannot buy it ahead of time and store it (it goes from solid to gas). A chunk of 20 ish pounds will probably last a few days. Probably roughly $20? I know that locally it can be purchased at a HyVee grocery store.
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has excellent info. Thanks for posting.
Iâm hoping in the new website, such discussions can develop into long-lasting threads with periodic updates from different people. Iâd be interested too in an overview of the options, the pros and cons, and recommendations. (Yes, I think like an engineer and love trade studies.)
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Lithium batteries are the way to go imhoâŠWe have a large bank of Battle Born batteries powering a 400 amp hour 240 ac volt system and are now building a second system using Volthium batteriesâŠThe Volthium batteries are the best batteries you can getâŠagain imho.
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What are people generally using as backup power generators when there isnât enough solar radiation (say, a very cloudy week or two) to make full use of solar arrays? Eventually batteries deplete. Propane generators? City power? Exercise bikes with generators?
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LiFePO (aka lithium iron, etc.) batteries are awesome, especially if you have to carry them around. Per useable amp-hour, theyâre about 5x lighter and 2.5x more expensive than flooded lead-acid (FLAB). Also, they donât like sub-freezing temperatures, and attempting to charge when cold will kill most of this type.
Sealed lead-acid batts (SLABs) are nice, especially for indoor use. Theyâre about 2x as expensive as FLABs, but you donât have the maintenance and spill worries.
Flooded lead-acids are the heavyweight cost leaders. Deep-cycle RV batts are great if youâre building up a 12v system. 6v golf cart batts are very rugged, and can be wired in series to get up to the voltage on the system youâre building. Also, these are probably the most commonly available type, and arenât nearly as sensitive to low temperatures.
Donât over- or under-buy amp-hour capacity on lead-acid batteries. Ideally, you want to cycle the batteries down to around 75% capacity in everyday use. If you go too small, youâll be draining below the 50% mark regularly and thatâs not good. Too big, and lead batteries wonât get the "exercise"they need.
Sizing lead-acid batteries for a small-ish off-grid system is something of an art. Fortunately, LiFePOs donât care about depth of cycle. They just care about the size of your bank account.
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We used to have a diesel generator, but the storage of diesel can be problematic. We had to add stabilizer to isolate the water that inevitably gets into the fuel. Once that generator died, we went with a propane generator. The fuel basically stays fresh indefinitely without additives. I really like propane for that reason (cue Hank Hill)
However, it seems no matter how much you plan, things will break. Our propane generator has died and seems to be repair resistant. Itâs been down for over a year now. Weâve had an expert look at it and heâs pretty much thrown his hands up. The plan now is to build a battery bank and use a small portable generator as needed. Iâm just waiting on an engineer to design the wiring. If your curious, we had a 2011 Generac 27KW propane generator, 1800 rpm, liquid cooled. Worked fine until one week before the big freeze we had here in Texas last February.
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If you havenât come across them, I highly recommend the Solar Surge videos on YT. Weâve learned a lot about solar from Joe Ordia. He has an electrical engineering degree from Carnegie Mellon and wrote a book detailing how he and his wife built a home with the intent of surviving off grid for a year. Will Prowseâs channel is also great.
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I have a solar back up system which is based upon a 24 volt 1000 Ah flooded-lead-acid battery. I have found that battery life is about ten years until charge management becomes difficult and excessive gassing and reduced capacity signal the beginning of the end.
I recently looked at replacing the lead acid battery with nickel iron. Which, by the way, I heartily endorse. I found that for equivalent capacity, the NiFe battery would occupy almost twice the volume. My space limitations ruled out the NiFe.
Right now, Iâm considering LiFePO but they are so expensive that the good old, reliable, flooded-lead-acid cells, despite their disadvantages, look to be the most sensible choice.
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Right now, I'm considering LiFePO but they are so expensive that the good old, reliable, flooded-lead-acid cells, despite their disadvantages, look to be the most sensible choice.Boomer, I think you've got it exactly right here, and give a good example for anyone looking at getting into off-grid solar. There are no "right all for all situations" answers with batteries, there are only engineering trade-offs leading to "optimal for this situation" choices. Flooded lead-acid is good stuff, but it's just not ever gonna be part of my backpacking gear! :^)
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Nickel Iron batteries are popular with people who read about them on the internet, not so much for people actually using solar. One big reason is their terrible efficiency. Lithium Iron Phosphate is 97-98 percent efficient, put a kilowatt hour or power in, get 975 watts out. Nickel iron is around 60 percent efficient. You need to generate almost twice as much power every day just to make up for battery losses.
For a backup battery for a phone substation theyâre great, they get charged up once and you just have to maintain the charge, efficiency doesnât matter. For solar, it does.
In the last couple of years Iâve added lots of lithium batteries to my solar system. I have 3 panel arrays at the moment, about 5KW each, feeding two batteries. My original battery was 8 LR16HC lead/acid, 24 volts at 840 amp hours or so, say 420 amp hour useable. The new battery bank consists of three 24 volt 600 amp hour batteries, so 24 volt 1800 amp hours, or about 45 kilowatt hours total.
The lithium batteries are so much better than the lead acid in every way, I canât overstate the improvement. First, lead / acid HAVE to be fully charged regularly, as in every day or two, or they deteriorate. Lithium doesnât care, they can sit at 20 percent for a week, which would kill lead/acid. Second, they charge much faster and more efficiently. With lead/acid, as they fill they get harder and hard to put more power into. Going from 90 percent to 100 percent seems to take forever. The lithium batteries just soak up the power until theyâre full, then they stop. The lithium are maintenance free, no water to c check, you donât have to worry about offgassing, etc.
I put off buying lithium because of a lack of good sources for parts. I built my own to save money, and for the last 6 or 9 months there have been good sellers with US supplies selling top quality cells at fair prices, so you donât have to worry about getting ripped. off by foreign sellers with no recourse. Theyâre not cheap, but I built my own for a lot cheaper than commercial, a 24 volt 600 amp hour battery cost me about $3,000 all in, with BMS, fuses, switches, enclosure, etc. On the other hand, I feel a lot better having a rack full of good batteries than I would have felt about having that money in the bank losing value every day, and who knows how long theyâll be available at good prices.
Docan Tech has a Texas warehouse, Iâve bought all my batteries from them with great satisfaction.
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CrLaan
I do not use 12V. I use 120V DC and connect solar panels to normal/regular/cheap/existing equipment. By not changing voltage, complexity, cost go way down, but requires a whole new set of very simple circuits to replace the profit driven complex/delicate computerized equipment, as described in the book âTake Back The Power!â at amazon book sellers.
I finished circuits (I have circuit boards or kits or completed units- will be UL approved this Spring sometime) for running overhead lights, and am working on single phase and triple phase motors up to 25 hp. Simply put some panels on your roof, and run the + and - wires into the box that connects to the existing store bought 120v or 240 v equipment. Save money when the sun shines. If no utility power available, you can run things if enough sun (or battery) is available.
Solar panels are so cheap that you can run serious appliances even when it is raining outside (10% of 10,000 watts = 1,000 watts). 5,000$ worth of solar panels in 2022 during rain/cloudy conditions = the same energy as 5,000 $ worth of solar panels purchased in 2010 and used during sunny conditions. This industry has been captured by bankers and the bigger installations are controlled for them to get their hands on your house equity.
I also have 120 V lead acid battery charger board for DIY but prefer buying 48-54 volt batteries for electric vehicles imported from China (put two in series for 120 volt appliances and one of my boxes).
I invite people to compete with me and dominate this space. You can find details for how to do this in the book. I prefer to work on radios.
Mots
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Hi BBQ MD;
I feel your pain. Hopefully, that seasoned expert EE will be helpful, sooner rather than later. Truth Seeker
The Battery University had spider diagrams to help with choosing the correct battery for the application.
For house power I chose Nickle Iron for the reasons already given. Weâve used them for the last two years.
At first they were very disappointing, until we found that No controller was necessary.
The batteries need to be hit with about 17Volts. Lead acid battery controllers will cut out before then, leaving the battery uncharged.
I suspect that the reason I couldnât find a controller for Nife batteries is because they would do nothing.
So. Just wire the solar panels directly onto the Nife batteries through an overload breaker and fuse, and youâre done.
Yet another high-tech device not needed.
The gazillion varieties of Lithium.
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Cooking food after the power goes out.
Actually, that may only work for a very small amount of food, whatever you can eat before it goes bad. After it is cooked, then what? It will go bad just as fast as uncooked food.
If you have very large amounts of food in a freezer, I think the best long term non-electric storage method is to dry it. That can be done over a grill as well, or simply using the original drying method, hanging in the sun. Dried meat and dried berries can keep for a very long time. I have lots of both, and they are good as-is or rehydrated.
They are designed to keep fresh caught fish on ice for several days. They will keep solidly frozen food from your freezer for many days. This allows you to cook it off more gradually. And you can keep it out in the snow in a shady place in a cold area, to get even more time. We also keep our two large freezers and a small frig in a back room that is not heated, and can open the window if the power goes out in the winter, to help the food in the freezers and frig to stay cold. Also, pressure canning is a good way to preserve meats, if you have a gas stove in a power outage. Better yet, can it when you first buy the meat or have it butchered. The old time women around here donât like freezers as they are used to the power going out when you least expect it. They say to can and dry everything you can. Having a large LP tank can last a year or two if you only use it for two people to cook and heat water in an âon demandâ heater. It might be a bit costly to fill now and then, but it can last a long time, especially if you heat your house and shop with wood. Make sure you have lots of wooden matches or a sparking flint/steel.
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Anyone want to start a battery thread? Or point to it if one exists? I tried to search but found the search function difficult to narrow down. This is very interesting stuff. For my part, Iâm invoking the permaculture answer here for which is the best battery? It depends!
Weâve settled on lithium for several reasons. As Bob pointed out, they require almost no babysitting to work. Our rural place is not our current residence. We live in a small city (pop. 110,000) which is 150 miles from âthe farm.â My husband telecommutes so if we ever get the Skylink we signed up for, he could also work from there. But our 2 kids are in school here and thereâs no plan to live there full time in the next few years until the kids are on their own. I can go up frequently to work on the small house weâre building and as soon as weather permits again, to work in the garden. Our kids are teenagers who refuse to go there unless forced to during peak gardening season. I prefer the serenity of being alone there so thatâs not too often. Theyâre way too cosmopolitan but I suspect theyâll have no choice and possibly even be glad of it if SHTF.
All to say, this solar system needs to be reliable and low maintenance. Obviously, longevity is important to us, but having this system in place and running is key.
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Donât go into hurricane season without one. These have saved my refrigeratorâs contents on multiple occasions. Tip: when you see something (anything, say a hurricane) coming a couple of days out, start freezing two liter bottles 80% full of water. They make dandy block ice, and in a pinch itâs that much more drinking water on hand after theyâve melted.
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Good call regarding canning jars on shelves. We are in earthquake country and I use either bungee cords and/or 1-2 ribbons across the front to stop them from all falling down. All depends of course on the shelving type. We also put our home canned jars in the cardboard boxes that new jars come in. That helps them stay in place. Lastly, Liquor stores have boxes for whisky, gin, etc that are all the same size - some with partitions in them. We cut the top 2/3 of the boxâs sides off and put jars in them too. Stops the jars from banging together and easy to write things on them: dates, contents, etc. GO for it!
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