Emergency Power Generation/Storage, EMP Protection, Heating/Cooling, Handy Tools and Tricks

What's the consensus here on the Lithium Iron Phosphate vs AGM Lead battery debate? I'm looking at building a 5Kw battery bank for a solar inverter. On paper, the lithium batteries are superior, smaller, lighter, and greater longevity with greater depth of discharge. I'm also aware of how they become useless if the BMS goes and tend to blow up in EVs. If one of those things goes my house is toast. Lead batteries seem more constrained but have more peace of mind. I don't know how reliable Lithium Iron Phosphate would be in a TEOTWAWKI scenario.

I think if you compare LiFe with LA with equivalent Amphrs (even at 50% discharge for LA), you find the LiFe bank to be much more expensive. The LA bank will have a long life so long as you stay above 50% discharge and you take care of the bank properly.
 
Here's what I'm looking at:
aims-lithium-chart.jpg
aims-agm-chart.jpg

In the best case scenario at 30% dod, the lithium bank lasts 3x longer and in most cases it's more like 8x longer. The total cost of the lithium bank is slightly more than double the lead bank (about an extra $1000) which would make it at least 50% more efficient, in theory at least. My main concern wasn't so much the initial investment, it's if these batteries are really as good as they say they are. When I first dreamed up this project I was solidly in the lithium camp for this reason, but since the technology has been pushed so much in EVs, there is some anecdotal evidence to suggest that the performance of lithium batteries is somewhat idealized and they don't reach their stated potential before either blowing up or the BMS deactivates them to keep them from blowing up. So I was looking for a second opinion on that.

My assumptions for the system is that it would be used after the collapse of the electrical grid, or due to supply chain issues grid power becomes prohibitively expensive. If they end up rationing a certain amount of grid power, the system wouldn't need to be nearly so resilient. Since the grid has collapsed, manufacturing and distribution has also collapsed, therefore sourcing new batteries will become difficult and so I wanted something to last as long as possible. Whether or not I'm alive long enough to care whether the battery bank lasts 3 years or 15 years in such a circumstance is an open question. We also have the Cassiopaeans stating that the collapse wouldn't happen for a "long time" in the latest session, so perhaps sinking a bunch of money into a really good off-grid system right now is a waste. If this is still decades out I kinda don't care, but the somewhat evasive way in which they gave their answer has me going with my original instinct to continue to try to put this together so I can be semi-independent when the time comes.

According to the electric company, it takes an average of 12 kilowatts per day to run my whole house. Getting rid of some parasitic loads and nonessential appliances such as the clothes dryer and water heater could probably drop that to about 8 without a noticable impact on my lifestyle. Over time, I would probably use refrigeration less and less which would drop it even more. The solar array is rated for 2Kwh, but due to clouds and trees and shading I'm estimating I'll only get 25% of that, so it might be barely enough. The real question for the battery bank is if I concentrate the heavy loads in the middle of the day, how much will I actually use at night. I guess until I hook everything up and run some tests I won't really know. The lead batteries would certainly suffice as a starter kit, but if I have to double the size of the battery bank to stay within a reasonable dod, then I will have spent almost as much money as if I went lithium in the first place and will have four extra batteries to deal with. I want to buy once cry once, if I can.
 
I re-did the comparison again for a 48V system. The Li batt I used is


The LA batt I used is this:


The comparison is 4 Li batts in series vs 16 of the 6V LA batts (2 banks of 8 in parallel)

For the Li batts:
80% of 300 Ah = 240 Ah for 5000 cycles (assuming 300Ah @ 20 hrs discharge)

For the LA batts:
377 Ah @20 hrs
Batt bank = 754 Ah
240 Ah is 32% DoD or about 3500 cycles


So performance is comparable and the cost for both is a little north of $6k - cost for Li batts has come down and cost for LA batts has gone up. So I was wrong about the cost comparison - they are about the same for similar performance.

Li batts are relatively new to solar applications and I don't know of anyone using them (my own system uses the LA batts in the above example). The concerns I have are similar to yours:
  • Is there any data demonstrating performance over the long haul?
    • The Li batt above has a 7.5 year warranty
  • The charge controller must conform to manufacturer charging requirements
  • Is the BMS reliable (no BMS required for LA)
  • Batt bank footprint is far less for Li (a big plus)
  • Under what conditions is the Li batt a fire hazard?
  • Is it safe to use a generator to charge Li via the inverter?
  • Is there any issue with maintaining a charged state over an extended period (weeks or months)?
I don't have answers to these questions.

My original LA batt bank is now over 11 years old. I gave it a pretty hard workout for about 2 years before preserving its life with only periodic use. It's in good shape and ready should the grid fail. It gets used during any local power outage.

When you run on solar, you confine your heavy loads to peak sun. I can run my washer and dryer (2 loads) on solar during peak sun and still get a full charge to the batt bank. Fridge/freezer loads are small. Once you get the system running, you will adapt to the charging cycle (or lack of it). An efficient use of a generator is to charge your batt bank when solar is lacking.

Use the attached spreadsheet to add up your power requirements - you can break things out by season or night/day or any way you like.
 

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  • Solar spreadsheet example.xlsx
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What's the consensus here on the Lithium Iron Phosphate vs AGM Lead battery debate? I'm looking at building a 5Kw battery bank for a solar inverter. On paper, the lithium batteries are superior, smaller, lighter, and greater longevity with greater depth of discharge. I'm also aware of how they become useless if the BMS goes and tend to blow up in EVs. If one of those things goes my house is toast. Lead batteries seem more constrained but have more peace of mind. I don't know how reliable Lithium Iron Phosphate would be in a TEOTWAWKI scenario.

I think if you compare LiFe with LA with equivalent Amphrs (even at 50% discharge for LA), you find the LiFe bank to be much more expensive. The LA bank will have a long life so long as you stay above 50% discharge and you take care of the bank properly.

My rudimentary understanding of lithium iron phosphate batteries (LiFePO) compared to older and more traditional chemistries is that they have a number of advantages compared to the older batteries/chemistries. A key and one of the main advantages seems to be that they have much higher cycle lives. Which basically means that you can use them for a longer time before they deteriorate and start to deliver less energy. That is, if you take care of them and/or use them correctly.

My understanding is that if you for example store pretty much any battery type without use, there are certain time spans where the battery will suffer considerable damage/loss that can go as far as destroying it (usually as low as 3 months without use. And most often 6 months without use). That means if you let such batteries sit in storage for longer than that (let's say 7 months or a year or more) you have to expect considerable loss/damage to the battery/chemistry and even to the point of destroying the battery!

Besides those considerations, we don't really know how LiFePO batteries will cope in the long run since it is a rather new technology that hasn't been used for so long. For traditional lead acid batteries, on the other hand, we know more or less how they cope in the long run since they have been in use for decades.

I personally have opted for LiFePO in some of my batteries, although I think it is perfectly reasonable to be on the "safe side" and use old school lead instead if you are worried how it will work in decades ahead.

By the way, there is a new kid on the block, that will apparently soon get mass-produced and might replace Lithium-ion altogether while being better than LiFePO in a number of ways: The sodium Ion battery.

One of the big advantages of that new battery/chemistry will be its ability to be used and useful in considerable minus temperatures, which is something other current batteries/chemistries have real big problems with.
 
My understanding is that if you for example store pretty much any battery type without use, there are certain time spans where the battery will suffer considerable damage/loss that can go as far as destroying it (usually as low as 3 months without use. And most often 6 months without use). That means if you let such batteries sit in storage for longer than that (let's say 7 months or a year or more) you have to expect considerable loss/damage to the battery/chemistry and even to the point of destroying the battery!
I have 2 LA 48V batt banks that I can switch between - the solar system only sees one of these banks at a time. Both banks have sat unused for as much as 6 months (at different times) with no apparent loss in performance. Before switching batt banks, I make sure the current bank is fully charged prior to switching.

The Li and LA batt banks will cost about the same so long as you design the LA bank to discharge no more than 30% per cycle - this brings the life of Li and LA banks into the same range.
 
I have been running my dehumidifier these past few days as the air indoors was quite humid and since it was raining all the time I couldn't open the window and it doesn't help much anyway... Apparently, there is a cheaper option. All you need is a big bag of calcium chloride (a desiccant) and two buckets and make your own dehumidifier, handy when there is no electricity and the air in your home is getting more and more humid. I have been wondering how people in the past got rid of humidity in unheated spaces, but calcium chloride could be useful. See what you think:

FWIW.
 
Where do you store a big new (unopened) butane bottle indoor (i live in an appartement), i though about storing it my wall closet and covering it with a sheet but I read it need to be in a well-ventilated place. So i though about putting it in my bathroom but I tend to smoke :cool2: a lot in my bathroom so... Is this irrational thinking ?
 
A new battery from China, to be sold in 2025.
The article is in french, but it's in fact a translation of the press release of the company, which means that it only focus on the positive aspects. But it looks more than promising.

Here's the link to the french translation :

And here the link to the auto-translation to english using G translate

Here are the relevant passages :

With reduced dimensions, 15x15x5 mm, smaller than a coin, the BV100 battery produces 100 microwatts of energy safely and stably for 50 years without the need for recharging. It generates energy every second, producing 8.64 joules of energy per day and 3,153 joules per year.
...
Atomic energy battery is a direct current power source that mainly uses nickel-63 as the power source and diamond semiconductor as the power converter . It is able to produce a pulsed power source with an extended lifespan by adding a supercapacitor as energy storage
...
The company plans to launch a 1W battery in 2025 .


I do not have the knowledge to comment about, had already hard to figure out where i could post this information :wow:
Cheers to all
 
Hello !
A french repost on my favorite french blog, here's the original link :

Here's the auto-translated link to english

In a few words : the plant named Miscanthus is cultivated in some villages in France and used for heat production (burned). It's a very low cost material for its purpose, compared with the high prices of almost everything to create heat, a good alternative idea, but this has to be taken over by (local) farmers. So if you have local farmers in your area, even more if friend with some/them, i would say ... spread the word, the information.
I'm not in measure to calculate if this would be also a good 'financial" alternative for our local farmers who are, purposely, attacked by our corrupted authorities in our occidental countries, they say, in the short Twitter/X clips that goes on with the article, that the farmers sell the ton of this plant at 110 euros. Is it low, high, correct ? I don't know, it's not my domain ...

One more good resilient idea, WEF will have harder difficulty to get rid of us, but on the other side, they'll find it harder and harder to hide or simply avoid to get shooted by someone whose cup is full.
 
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