Off Grid Batteries

Excellent advice this last AnthonyB.
In all things in Life the over-reaction; the jump-away; or the reach-in to save, can damage worse than the stimulus.

All the advices here are good. I am glad this has come up.
Especially including that Life is inherently risky and dangerous. Live-a-Life of caution, and measured risks taken, sure.
But do live that Life.
Steve Unruh

3 Likes

I found this article;

Those working knowledgeable . . . comments? Opinions?
S.U.

3 Likes

I used to have a job as a project superintendent for a company that built automotive paint systems. It was part of my job to get the work area set up and get the welders installed. We had electricians to tie into the factory bus bars to power the welders and I had to take one up on a scissors lift to plug into the bus. First he wandered around until he found a piece of four by four and handed it to me. What’s this for, I naively asked. He said, you are going to use that to knock me backwards if I get grabbed sticking in this plug. Being as the scissors lift was all metal I had a hard time seeing how I wasn’t part of the circuit.

4 Likes

Hi, are any of you all using grid power as a back up to charge your battery bank? If so what is a good 120v ac, or 240v ac 48v charger. Also is there a good balance charger for lithium batteries?

2 Likes

Dear Al,
I hope you are well, and having a great new year so far.
I can pass generator power through my inverters @48vdc and 30amps or 50amps depending on the inverter. They also have charging curves for LiPO4 or Li-ion.
If I had grid, I could do the same with that as well.
I also have a 240ac to 48vdc golf cart battery charger. It came with one of the carts.
Come to think of it, I bet the old Lincoln SA200 could charge the 48v banks as well.
BPJ

5 Likes

Al the best solution is what they call a hybrid inverter. It will sit between your batteries powered system and the grid and or your generator.

SCHNEIDER inverter can even provide the AC output wave to use solar panels designed for grid connected systems off grid. I haven’t tried that setup just read how it can be done in the manuals.
But I believe it would be possible to use their inverter with those solar panels and no DC charge controller off grid. Which is interesting because you see the panels with build in inverters for grid attached systems sold pretty cheap used by people who get into issues with their roof and don’t want to put them back up.

4 Likes

I’m not sure how youtubes algorithm for video’s works, I was on ‘how to play ‘little wing’ on ukulele’ the next link was ‘Don’t Waste Your Money On Batteries - The Shocking Truth I Discovered When Testing RV Batteries’ which basically went through and tested various lead acid against LiFePO4 batteries. The short conclusion is LiFePO4 batteries cost a minimum of half as much as any type of LA battery over their life cycle, and the LA lifecycle was shortened over heavier loads then like 2a.

However, that is pretty basic knowledge and has been out for a while. What I haven’t seen, or don’t recall seeing is heated LiFePO4 batteries since they drop in performance significantly when they get to freezing temps, these include a built-in heater to keep them up to temp.

The link to the youtube video that rudely interrupted my attempt at ukulele playing is:

1 Like

Hope someone has an explanation for this.



These are Duracell golf cart batteries. I bought them in the spring of 2021 and didn’t connect them until recently but kept them charged with an automotive charger. Then I hooked them together for a 12V 420 amp hr bank. I didn’t charge them with the battery charger until the other night and the first one in the bank blew it’s top. No idea why. The other three batteries are still charged to 6 volts. Would have thought there would be acid all over considering the caps ended up at the far end of the bank but there wasn’t. Any ideas. This stuff is way outside my wheel house.

3 Likes

Maybe the case was faulty from the factory.

Looks like the safety vents weren’t good enough.

Are these 6v batteries or 12v?

Charging them connected in series or all in parallel?

When I zap dead batteries back to life I leave the vent caps off and they’ll offgas so hard it almost comes bubbling out the top if I don’t turn off the power every now and then.

2 Likes

In the photo if looks as though you infact hooked the negative of the first battery to the positive of the second battery and the negative of the second battery to the positive of the 3rd. Battery i can’t see on my phone where the negative of the last battery is connected or how the charger was connected. But if you want them in parallel for a higher amperage at 12 volts the wiring looks wrong it looks like you wired them into serried which would make a 36 volt system st the current rating of a single battery. My guess is the battery which blew was being pulled to the wrong voltage level by either the other 2 batteries or the charger based on what i can see of the bus bars. Back in the 90s i was part of a solar car club in college and the professor had a photo of students making the mistake of setting batteries in a circle late at night and hooking them together in serries to charge them at a higher system votlage except the the student hooking it up was working around the circle and hooked the first and last batterries in the loop together. When he droped the wire onto the terminal it instantly melted the terminal and vaporized it and the wire became of the wiring mistake this photo reminds me of that one.

3 Likes

hmm have not seen that before, 55 amps on the charger isn’t very high either… were they equally charged when you banked them together? Only thing I know that can cause strange things to happen like that is a dead or low battery banked with a full charged one next to it and acts like some sort of a dead short and zaps the charged battery down a bit. But I think Cody is onto something, I do not think it was venting correctly and over built pressure to pop the top off like that…

2 Likes

I’ll check the routing again Dan. Wouldn’t surprise me if I screwed it up but I thought I was doing it right.

4 Likes

Tom could you take some more photo’s maybe from above that are in focus get the whole pack in if possible

3 Likes

One of the big fears for me looking forward to a carbon priced future is how i will charge my car(s).

Limits are around a 100amp service I have no interest or desire in upgrading.
I really don’t use that much hydro and don;t like doing electrical work ( I get enough of that at work I don’t care to rewire my home )

The solutions we already know and talk about here all the time.
Renuable generation and storage.
Could be solar, wind and biomass but we need storage and Lithium technology is expensive and comes with risks of fires.

To that end I have watched for years as Aluminum technology has moved in fits and spurts.

Now it appears a low temperature sulphur Aluminum battery is feasible and intrinsically safe for domestic use.
Will it be cost effect?

2 Likes

Sadoway is the real deal and his Ambri company is working on a different grid scale battery type that is really exciting - molten metal but cheaper and higher temps than this. The aluminum sulphur battery chemistry also caught my attention because it could easily be residential at those temps. I’m a former student of his - hence my research paper linking habit.

Like a lot of things with batteries… it takes a long time to get batteries from the lab to a cost effective retail product.

So while it isn’t new tech, I’m pretty jazzed for the LFP packs that have been hitting the market at like $0.30 per watt x hour. Overspec your cheap solar array, go a little light on the spendy batteries for now and live like a gridder? Cars rarely deep cycle anyhow. Top them off a dozen kwhrs when the sun shines and live your life.

Re: Drive on Wood…. keep some charcoal on hand and a genset at the ready for power gaps and you won’t miss out on the grid a bit.

1 Like

Looks like it was wired wrong, and that battery was wired as 6v, and then overheated and boiled off the acid from being charged at 12v. The two wires that go off the top of the picture are both connected to the same battery on different poles is only 6v, but when that completes the circuit it is getting backfed 12v from the rest of the battery bank?

4 batteries for 12 volts should be wired with 2 together in parallel and the two banks in series. (or vice versa, I would have to look that up to see if it makes a difference. ) Then you connect the to opposite ends of the series connection like negative would go on 1 parallel bank, and positive on the other. And when in doubt put a multimeter on it.

3 Likes

That was my thoughts as well Sean ,but could not make out the photo enough for my old eyes as it looks like the cell that exploded has the copper bus bar from a Neg to a Pos on the battery next to it , thats why i asked Tom if he could take some clearer photo’s

2 Likes

Because I was poking around and stumbled across a chinese company building a prussian blue and prussian white manufacturing facility for use in Sodium ion batteries. I poked a bit further. It appears as though there are several companies that are planning on production of sodium ion batteries. One is CATL in china, who mentioned production in 2023, Swedish company Altris in Europe who is getting funding for a factory. Natron in the US, is planning on a small facility in 2023. Faradion, which is a british company purchased by India’s Reliance Industries, and they are planning on a factory.

Sodium Ion has a lower density as lithium which is okay if you are doing storage. Instead of 10 semi trailers you need 12. It isn’t that big of a deal. I have not seen much for cycle except they don’t form dendrites like lithium. They do operate up to like -20C. I haven’t seen much on price but except lithium hydroxide is 70k/metric ton and sodium hydroxide is around 800/metric ton. Lithium was originally like 7k/metric ton in 2019. And there are a couple of different chemistries for it. mostly sodium cyanide with prussian white or prussian blue derivatives. so there is quite a bit of room for improvement in the technology.

2 Likes

Researchers are working on some really interesting chemistries. Sodium as a metal is as cheap as it gets, especially versus Lithium.

Transport focused batteries really have a different set of optimizations compared to stationary storage. In time I expect the battery market will be large enough for large research budgets in all those directions and production to follow.

It wasn’t long ago that Tesla was building battery packs out of cells intended for laptops. They have certainly moved on from there.

1 Like