I agree Kamil. They may not be the most efficient but they have served us well for a long time. I know several people that have been running their homesteads for many years on Trojan T105’s. If nothing else is available this book says I can make my own from used ones.
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I have managed to get life back into old forklift battery’s for a little over the price of scrap battery’s ,I use a Variac to drop the input ac voltage to my old style 12 volt battery charger and charge 2 cells at a time and run that at around 5.5 volts at around 10 amps for how ever long it takes to get the plates clean enough to get a SG in the fair to good range on my Hydrometer and then move onto the next 2 cells .
There is a English chap called Andy Reynolds on YouTube who does this and he explains it a lot better than me .
Dave
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If you have T 105’s or T 16’s i guess you can do the same and set it to charge the 3 cells at a time of those battery’s as well .
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Here are a couple of wood based techs. One is finnish, one is swedish, and one is swiss. They are replacing the graphite in the anode with carbon made from tree lignin.
The swiss one is the most interesting to me because they printed the cell on paper which means it could be pretty cheap to produce at home. but it might not last very long either.
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Apparently you can use clay for a battery of sorts.
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Robert Murray-Smith has a great feed.
I spent a lot of time learning about liquid desiccants and mostly skipped over zeolites but they are really interesting. I think “Battery” is a little generous description but the notion of bone dry zeolite as a ready heat source could be really useful, especially given how cheap and stable the zeolite is.
He has a recent video (1964) on passing electricity through a rotating joint without slip rings that was super interesting and maybe helpful to forum members.
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I think it qualifies as a battery but energy storage is probably a better term. It would be a pretty cool set up with solar thermal. You can dry it in the summer, and add water in the winter.
With a peltier using outdoors for the cold side, it would work better for generation, but peltiers aren’t that efficient. maybe emergency lights if the generator goes out type of thing.
I will check out 1964 because slip ring junctions are super expensive.
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Peltiers are not very efficient but they are a simple way to get electricity from heat: no moving parts and all in one go (versus a heat engine and a generator)
For thermal storage, in general you are best off using thermal storage to generate low grade heat… like keeping your home warm. The temperatures that zeolites get to probably aren’t high enough temperature to drive a heat engine (Carnot limit and all) or create much electricity on a Peltier.
The drying effect of zeolite could be excellent for cooling though. A water chiller or dehumidifier run on zeolite would be neat. The bone dry but ambient temperature air it creates can be easily cooled with a little evaporation.
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Zeolites can be used for refrigeration, combined with a simple vacuum pump. With a water container, zeolite container and pump to remove air to below the vapor pressure of water and ultimately ice, the water will boil, then freeze. The zeolite adsorbs the water vapor much more quickly than you could pump it out mechanically. I’ve done very small scale demonstrations with a hand pump, but the method scales up. As with gasifiers, leaks will ruin your day. If nothing else, if you’re doing the pumping, it makes you appreciate electric refrigeration.
If you want to fiddle with this, some kitty litter is zeolite-based. Look for litter that looks like little, irregularly shaped rocks, not the pellets (though they may work, I don’t know). There are man-made zeolites that somewhat more efficient. They will often be uniform pellets of various shapes. Also more expensive.
It’s not hard to freeze a few drops of water, but it’s real work and big quantities for useful refrigeration.
edit: The man-made zeolites are called molecular sieves.
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I just watched a video on how they use zeolites to create high vacuums for experiments.
When I had a day job, some of the labs used sorption pumps. Very clean without the mechanical pump oil, but liquid nitrogen is less common out in the country 
edit: By the way, charcoal works similarly 
but works best with liquid helium 
Charcoal is similar, especially when you are looking at the pore sizes in activated charcoal products and the expansion of the surface area which is the sieve part, but with the microsieves there is also a loose bonding that occurs on between the gas and the surface, so they kind of stick together. And I don’t know if that happens with charcoal or charcoal is ‘sticky’ with other molecules.
I was looking at batteries, and came across redodo batteries, and while checking them out, and reading reviews for them. The one thing that stuck out is they dropped in price by 100 dollars over the last year given what was said in the reviews. (plus they have a sale going on) but it is 230 dollars + shipping for 12v 100ah batttery, and they can be hooked 4 in series for 48v. The have heaters in them for cold weather. But I didn’t have time to watch a tear down type of video.
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Sean , i tried looking for where it said 4 can be used in series to get 48v but being old and tired i couldn’t see that bit .
Just make double double sure they can be used 4 in series , as it is very unusual for budget batteries to have a BMS that will talk to between 4 at the same time , the most my batteries would do is 2 and they were a grand each , but maybe things have moved on since i got these .
Dave
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It is unusual that is why I mentioned it, and started looking for reviews.
“【 Max. 20.48kWh system expansion】 Redodo 12V 100Ah LiFePO4 batteries can be expanded to max. 4P4S as a 51.2V 400Ah LiFePO4 battery system with 20.48kWh energy & 20.48kW output. The flexible combinations make it perfect for your RV, camping, van, solar home system, etc.”
NOTE: I do not see in this desc where they talk about warming the battery in cold temps. I read or saw it before… but it is odd they didn’t mention it. but I was reading the refurb description…
They also make a half size Mini for like 20 dollars more that saves approx 1/3 the install space. Oddly that description mentions 4000-15000 cycles.
They claim to be compatible with Zoom batteries so probably the same battery with a different label.
I think this is the zoom battery. they are saying 4000-8000 cycles. but even at 4000 cycles, on sale, they are only 5c/kwh for storage cost (increase for shipping and taxes) and installation. but Michigan’s DTE utility has a 11c spread between peak and offpeak for consumers on the dynamic peak pricing plan. The other major Michigan utility Consumers Energy doesn’t have as good of pricing scheme only have like a 5c/kwh difference.
Let us know how you get on if you decide to take a chance on them , if they will do what the label says then they are a bargain for sure , you could almost build a Powerwall out of them for cheap .
Dave
If they spec out, where they shine is replacements for lead acid batteries in an existing systems, but non-engine starter applications. So existing off-grid, RVs or even small motors like trolling motors, or wheelchair motors. Although I think they said not golf carts but that might be a voltage issue or size of battery issue, but it could also be a cooling issue. I don’t know.
With the Federal Tax credits the way they are, Tesla is claiming I would have a potential of 2800 in tax credits with their system. which drops the 8400 for 13.6kw down to 5600, and only leaves 2200 for an inverter/charger and wiring for the batteries to get to what a powerwall would have if DIY batteries and the rest of the system doesn’t qualify for any tax credit, and it very likely wouldn’t qualify for as much tax credit. The other difference is I would have to use a Tesla certified electrician, instead of the electrician of my choice which could also be quite a huge difference in $$.
The math isn’t quite as straightforward as it initially sounds for energy storage. I got carried away, because I didn’t think it was that close. I was actually eyeballing them for the trolling motor type of application because it is only 60 bucks more then a deep cycle battery and FAR more charge cycles… if they skimp it is on the output power electronics, or the capacity, the charge cycles is within lifep specs.
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Sean,
I know very little about Tesla products or Generac, etc., but I would be checking length and quality of warranty service and factoring that into any DIY vs. Factory “Power Wall” type system for my home. DIY savings is great until you have to pay for some stupid thing you did not plan for. 
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It is a valid point. Along with the warranty, the company has to stay in business as well to honor it.
You have to carefully run through the risk vs rewards. Knowing -what- you are doing is half the battle, and even then it may not be worth it. A lot of DIY projects for me, any savings is spent on a new tool that I needed to get the job done.
Even if you go the powerwall (which we are assuming is more expensive and it may not be) route, you still might end up ‘ahead’ depending on the spread between peak and offpeak times.
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Apparently some south koreans found zinc water batteries that if they coated with copper oxide, would prevent dendrite formations (basically cracks that internally short the batteries) so they last 3000 charge cycles. What they are doing is electroplating the zinc onto the copper oxide.
I started looking through part of the paper, but it is actually something that seems possible for the DIY person.
short version
Actual paper.
https://onlinelibrary.wiley.com/doi/10.1002/aenm.202401820
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