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Off grid ideas

And Samuel...
perhaps you are already aware of this, but I am aware of two 'mostly-US' sources for NiFe batteries.

One, with a bit of a history, is ZapWorks; they were doing reconditioning at one time of old original Edison cells, but had some funding issues trying to go into new manufacturing. I heard there was some progress of late, but haven't confirmed that first-hand.

And the second is a manufacturer called "Iron Edison": https://ironedison.com/
 
@Mark C I am in New Zealand, so I would have to import batteries anyway. Iron Edison just imports from China. It would no doubt be cheaper to just import from the manufacturer than have a US agent also taking a cut on the way. They're available on Alibaba.com direct from China, worth checking out by anyone interested, but still not cheap.
 
And I can recommend @Mark C's Hebrew Nation Radio shows, I often listen to these, thanks for putting them on.
On that note, I keep forgetting to tell you about a phrase you commonly say. It's "I couldn't care less", not "I could care less". "I could care less" means "I care a bit about it because it would be possible for me to care less than I do". "I couldn't care less" means "I don't care at all about it, so it would be impossible for me to care less than I currently do". Must be an American thing though, because you're not the only person who mixes up this phrase.
Brilliant analysis of what's happening in the world in the light of Scripture, and I admire your willingness to speak on polygyny even when appropriate.
 
Mark C said:
Once upon a time, I was a 'token messianic' here, as a Sabbath keeper -- teacher of "Torah as Written" -- and became persona non grata... (isn't that what Yahushua told us anyway?)

I'm happy to see that over time things appear to have changed. Meanwhile, though, I added new ministry responsibilities (Hebrew Nation Radio, our own small local fellowship, Shabbat Shalom Mesa, which has a much larger on-line presence -- Paltalk this evening, erev shabbat services, live teachings tomorrow, etc -- "Walking Torah with Shabbat Shalom Mesa, for those that are interested, WayToZion.org, www.markniwot.com, and so on...) and just plain got out of the habit of looking here.

It didn't help that I either forgot the password over time, or it expired when the new format here came up.

Hello...
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Lol, hello. It's good to see you again.
 
Thanks all for the kind words, and I'm thankful to hear that the shows can be a blessing.

And I appreciate the reminder, Samuel - although sometimes it's true I couldn't care less, other times I jes' might... ;) And we're always happy to show potential new folks around the Boondocks here, DesertFamily -- it might, or might not, be as dry as you're perhaps used to, but there's a lot of room and solar potential regardless.
 
PS> I appreciate the link to the Chinese battery sources, too, Samuel. Do you have any independent info on quality feedback, or which manufacturer sources the Iron Edison label? (not that I can afford anything immediately, but they Would Be Nice, before the Coming Grid Failure...)

It should not be overlooked that even a small, "daily use, high discharge" NiFe pack, at 20% or so of what we have capacity-wise from lead acid cells, especially with a lot of sun, should dramatically extend the life of the other batteries, by reducing the cycle discharge they see.
 
Iron Edison says:
The industrial series Nickel Iron batteries are imported from one of the largest battery factories in the world, located in Sichuan province of Western China. Our production facility has been building batteries since 1971, and is known for producing the highest quality batteries available.
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Their batteries in the photos look identical to photos on Alibaba. It's a low-demand product that would be expensive to set up a manufacturing facility for. I have formed the impression that there is only one manufacturer and everyone sticks their own labels on the same batteries, but I could be wrong.

I had not considered two parallel banks, one lead-acid and one NiFe. That is an intriguing idea. Could you just wire them in parallel with the same charge controller, with the initial load naturally coming primarily from the NiFe due to different discharge rates and slight voltage variations, or would you need a more sophisticated setup than that? Do you know of anyone who has actually done this? I suppose you could have the NiFe as the primary bank connected to the charge controller and inverter, with the lead-acids charged via a dc-dc charger whenever a high voltage threshold was reached (ie the sun is out), and then have the inverter switch over to them when the NiFe reached a low voltage threshold, but that's adding cost and complexity. Parallel banks would be far simpler.
 
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Ooooo!
Parallel banks?
I am liking that idea for the "hotel load" on my truck......
 
ZecAustin said:
Sigh...there was a time when I understood what was being said on this forum. Now every single post is so far over my head I'm pretty sure it shows up at NORAD.
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I can kinda tell which way they are going by following their dust.
 
@FollowingHim - "Parallel banks would be far simpler." (and thanks for the info; didn't see that, but it did look like a lot of the Chinese batteries I saw on that site were different manufacturers, based on configuration. I'd really be interested in seeing real prices, and maybe even curious at some point about a larger purchase. I know a local guy in Alamosa who has a solar store, might be interested.)

Sorry, but that definitely will NOT work. (For the same reasons that it's not even recommended to put older Lead Acid batteries in parallel stacks with newer ones; the "don't play well together," and won't share either load or charge properly.)

And sorry, guys - didn't mean to wax obtuse on what might be, to those that haven't been involved, a somewhat technical topic. (Guess that goes for the whole site here, to come extent, doesn't it?;) )

The best answer is to switch the batteries onto the load (inverter, feeding the house) . I'd run off the NiFe (good) batteries most of the time, during the days, and overnight, until or if they get discharged. (However far that is; the nice thing is that they can go MUCH deeper into discharge than the lead acids.) Use a great big motor contactor, "break-before-make", so that they are not even even briefly connected in parallel, and most inverters should have some output that would be useful. (I.e., instead of just starting the backup generator, it would switch the contactor relay to select the backup battery set.)

I have multiple charge controllers anyway (for more panels) - it'd be a simple matter to split some onto the 'backup' battery pack, or even just put a little array on them, or a charge controller, since hopefully they'll just "float" and be in reserve most of the time.

Oh, and I did talk a year or so back to one of the principles at Zappworks, that was refurbishing old original Edison batteries. He agreed, that it worked well, and had set up several arrangements like that for their customers. (Some that wanted new NiFe already had the others.)
 
Mark C said:
"Iron Edison": https://ironedison.com/
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Thanks for this. I didn't realize Edison batteries (nickel iron) lasted that long and were so capable. A definite, cost effective alternative to Lithium for a home set up. Can't beat 20-30 years of 80% DoD everyday. That's crazy.
 
Mark C said:
it did look like a lot of the Chinese batteries I saw on that site were different manufacturers, based on configuration
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You're right, I may have been mistaken when I last looked at this. I believe Sichuan Changhong Battery Co., Ltd. is the manufacturer of the "Iron Edison" branded batteries - the location is as described by Iron Edison and the batteries look identical. There is an Australian retailer that appears to be selling these also, rebranded as "Iron Core", they could be an option for me. These batteries are available from some Chinese retailers on Alibaba.com also.

Regarding parallel banks - I am very well aware that different batteries don't tend to play well together, what I was wondering is if it would be possible to rig them in such a way that the bank getting the short end of the stick was the nickel iron ones - but given the voltage ranges of each I think it is the lead-acids that would get thrashed, so that really wouldn't work when I ponder it further. Full switching would be the only option.
 
As far as parallel banks go, you can do it thru some creative use of diodes (yes, big ones, if needed) and your battery management system(s). BMS's are required for Lithium batteries (even individual 18650's can come with tiny ones already attached) and are designed to disconnect when they hit a specific voltage to prevent over-discharge. The bigger BMS's for modules are usually fully programmable. I'm assuming that Nickel Iron batteries would also require some type of BMS. If they do, then there should be a built-in cut-off.

In my mind, I see Solar panels branching to both banks' BMS. Each BMS output, via their own set of diodes, then goes to the inverter. By using diodes on the BMS output, you isolate each bank from "seeing" and interfering with each other. When either bank reaches its low-voltage cutoff, it just disconnects. Now, there are some issues with spikes related to that, but that could be handled by utilizing capacitors. They're not that expensive and many car audio enthusiasts use them to handle peak loads from their amplifiers*. The caps would act as a buffer during switching or when you have a high-surge load like for a compressor.

OK, the question i think also brought up was using one bank before the other. i think you can, but would be slightly inefficient. Let's say you want your Edisons to discharge first. That's probably ideal because it allows your high-rate Lithiums to soak up any surges. So you wire it Edison BMS Output > Lithium BMS Input > Lithium BMS Output > inverter. You just daisy-chain them in order. Your BMS acts as your output "diode" to keep it all in one direction. If you were using Lead, i would go > Edison > Lithium > Lead > Cap > Inverter. Your Leads may not be able to handle the peak loads too well (Caps), and, of course, you want them to discharge least/last.

On the Daisy Chain, notice I didn't mention the Source/Solar as first. That's because it wouldn't actually be first, but parallel, like in the first example, to each BMS Input - with a diode on each leg. That way they can all charge at the same time instead of Bank 1 charging Bank 2 charging Bank 3. Some of that will happen anyway, but in addition to the direct charging. You still need that diode on the direct solar leg to keep the BMS's from interfering with each other, Bank 1 trying to use that leg to skip to Bank 3, or worse, feed back into the panels at night (for those that don't know, that's why panels should have a diode on them anyway and why I discourage direct panel-to-battery connections).

All battery Banks should have a BMS simply because they basically do exactly what you are describing, without having a separate contactor or switch and is a huge protection for your expensive investment.

Of course, i could also just be some random internet monkey banging on the keyboard. :D


* I saw one guy who left his truck lights on at work. Nothing but clicks from the starter solenoid. Opened the back of his camper, turned on the cap for his amp and was able to start his truck. That was one 12V cap smaller than a 500mL bottle - almost 20 years ago.
 
The issue I can see with that is that Nickel Iron batteries have a much wider voltage range than Lead. A nominally 24v lead acid battery will charge at 28-29V, and discharge down to 24V (50%) before needing recharging. A nominally 24v nickel iron battery will charge at 32V and then discharge comfortably down to 22V or even less with no damage. Unless I have misunderstood you somewhere, even with diodes, if they're parallel the voltages in each bank will be the same. This would mean that if the charging voltage was raised high enough to fully charge the nickel irons, the leads would be overcharged, and then the leads would be discharged to a damagingly low level before the nickel irons. The leads will be being thrashed while the NiFe were being underutilised. This would drastically shorten the life of the lead acids. I can see this working with battery banks that were the same chemistry though.
 
ok, so if we're discussing parallel banks, then we have a fully charged 29V Lead-Acid Bank (LAB) and a fully charged 32V Nickel Bank (NIB). They both have diodes to the Inverter. The higher-V NIB would normally try to charge the lower-V LAB, except the diode on the LAB prevents it. The Inverter will receive the 32V from the NIB until the voltage drops to 29, where the load is now shared by both banks. The total bank voltage will be self-balancing until the LAB reach 24V where the BMS shuts off the power to prevent damage. The load is now back to the NIB where it will continue to discharge till 22V where that BMS shuts off and now no power from either.
Charging from Solar (or other Source) will be directly parallel to both BMS Inputs at 32V (or whatever V) because the independent BMS's will control actual V and Amps to the individual battery packs themselves. When the LAB reaches 29V, the BMS will disconnect the Source power and all available power will be used by the NIB BMS.

I can see the Daisy Chain appearing to being slightly more complicated but maybe not. Let's figure this out (and i'm seriously typing as i figure this out. I don't know what I'll say. :) ). Ok. Let's define the Primary Bank as the one directly in front of the Inverter. This will be the one that stays charged the longest. The Secondary, the one behind it and gets used up first. So our Primary is going to be the Lead Acid, the Secondary the Nickel Iron. At full charge, the NIB will be at 32V and feeding the BMS for the LAB. The LAB will be supplying 24V to the Inverter. As the LAB gets used, the V will drop. As the V drops, the LAB BMS will use the 32V from the NIB to keep them charged. Remember the BMS, by design, self-regulates. So, the LAB keeps getting used and charges from the NIB until the NIB reaches 24V. Now the LAB BMS is supposed to shutoff. If it does, the extra 2V in the NIB just sits there. I see the problem.

2 possible fixes off the top.
  1. use a MPPT between the NIB and LAB that will boost the voltage from the NIB to continue charging the LAB until the NIB reaches 22V. But you introduce an additional efficiency coefficient and MAY reduce your overall available kWh.
  2. Increase the NIB pack size. The packs I've seen are actually 1.2V open air (you can see them, they're not in an actual package) "bricks" wired in series. If you were to add an additional brick, the extra voltage will take into account the difference in Charge. For example, you said that a 24V NIB is 22 to 32. If that 24V was made using 20 x 1.2V cells, then an additional 1.2V cell would bring the discharge level up to 23.1V, and a second additional 1.2V brick is now 24V which is your LAB shut off level. All you have to do is reprogram your NIB BMS to charge up to 35.2V and disconnect at 24.2V
How does that sound? Or am i way off my rocker?
 
From what I have read, you actually sometimes have to use one fewer NiFe cell to keep the voltage down low enough for standard equipment that was designed for lead-acid batteries to actually work with it. I suspect that adding extra cells to make the voltage even higher would in practice take it out of the tolerance range for standard inverters & charge controllers.

I am positive that there would be an electronic way to make a completely smooth system that worked really nicely, keep thinking and you're bound to design something really neat - but the more electronics you add, the more there is to go wrong, and this all adds to the expense too. And when things go wrong with such a system, they can be harder to troubleshoot also. While Mark's suggestion of simply switching to one bank or the other will certainly work, so there already is a solution. The best ways are usually the simplest ways.

And from that perspective, the more we discuss it, the more convinced I become that I just need to save up for a single large bank of NiFe batteries and not try anything "fancy" at all...
 
I didn't know NiFe was even a thing*, so I'm jazzed about that. Didn't want the high maintenance, mass and ecological concerns required for Lead and couldn't afford a start-up Lithium pack to make it worth my time. But, NiFe? Different story. 80% DoD for over 20 years? Sign me up. Change fluids every 7 years instead of entire packs every 5? Twist my arm why don't ya.

* As in, I understood it as an Edison construct but not that people were actually building and using them today.
 
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