The great battery thread

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For an electric furnace my father-in-law had to install a 600 amp panel and pay for the 600 amp supply. He kept it for three years and went back to gas. It was very expensive and the furnace was in need of constant repair. It was quite a fiasco.
Originally he was using oil forced air heat and the price of oil was going up. In Seattle electricity was cheap and he got a rebate for the change. Electricity started to get more expensive and all the problems with the furnace made his mind up to go to natural gas. That was probably the best decision he could have made. Seattle started taxing the fuel oil so it went up even faster than automotive fuel prices.

When I built my garage and shop here in eastern Washington I decided on a heat pump because it is cheaper than gas. From here on heating and cooling will all be with heat pumps. They are dependable and more efficient than anything else.
 
What would that work out to, about 12kW of panels? I'm too lazy to look up actual numbers. That's a significant amount of power when the sun is shining.
Enough to run a winery like I've seen here in southern Oregon. Our system, with eight 195 watt panels for a total of 1,560 watts and twenty 6 volt golf cart batteries was in the $10,000 to $20,000 range, thinking of what a 12 kw system would cost would add up to what our credit card debt was before we went debt free, $50,000 and that's probably still not close to what that kind of power would cost.
 
When we first moved to this area we were renting and all electric town house... The 2nd year we were here we got 2 storms back to back with each dropping over 3' of snow. The power went out and we had no heat, no hot water, and no way to cook and it was 19 degrees.... We set up tents in the living room and tried to cook on a gas grill (does not work well in that kind of weather). 8 days later the power was restored and we had shoveled about 300 yards to get to the main road.

We we bought our house it has gas water and furnace, I installed a flat topped wood burning stove, and power was still an issue. 20 years later and I have added a manual transfer switch and have a generator sitting in the shed with a few gallons of gas. I learned that trying to pull the generator out of the shed and start it in a dark freezing rain was no fun, so I added a battery backup automatic transfer switch (2kW) for 1 circuit in the house (to cover the wife's oxygen concentrater), I also added 3 UPS points to provide power for some key electronics, just enough to cover my needs for about 6 hours. This way I can switch over to the generator in daylight, which is much easier. I would prefer to have a single all in one solution but when you start looking into the cost it can really set you back.

I have friends that have grid connected solar, but they learned the hard way that when the grid goes down, they do too, because they need to protect the line workers from electrical feed back.

Nothing is ever as simple and inexpensive as we would like...
 
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I knew a teacher that had a large solar array that was grid tied with no batteries or an inverter for a standby system, don't remember if I offended him by asking why in the world he didn't, I think it may have been one of those, pat yourself on the back because your helping to be green minded, of course when the power goes out, they were in the dark, I don't think they had a wood stove either. That kind of thinking just doesn't make sense to me, actually this guy was someone that I talked to a lot about things going on in the world and he put me on to the blood type diet book. As time went on he seemed to change, as in being a snowflake, he and his wife sent me and e-mail saying that our politics were opposite of what they believed in and no longer wanted me to send e-mails to them. I'm sure that with the crazy things that are going on now and what's happening to the economy, he may remember that he told me, he didn't want to hear anything about gold, silver and the coming economic crash.
 
I knew a teacher that had a large solar array that was grid tied with no batteries or an inverter for a standby system, don't remember if I offended him by asking why in the world he didn't, I think it may have been one of those, pat yourself on the back because your helping to be green minded, of course when the power goes out, they were in the dark, I don't think they had a wood stove either. That kind of thinking just doesn't make sense to me, actually this guy was someone that I talked to a lot about things going on in the world and he put me on to the blood type diet book. As time went on he seemed to change, as in being a snowflake, he and his wife sent me and e-mail saying that our politics were opposite of what they believed in and no longer wanted me to send e-mails to them. I'm sure that with the crazy things that are going on now and what's happening to the economy, he may remember that he told me, he didn't want to hear anything about gold, silver and the coming economic crash.

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Ben
 
I remember my dad having those three monkeys as a young boy, it would have saved me a lot of grief over the years if I had just kept them in mind.
 
I know you said serious battery discussion but I just want to post this video for a different look at batteries.
Do NOT try this at home. :rolleyes:



That was amazing to watch, it created so many questions, what was on the white plates, did they just refurbish all the old lead plates, ???? It would be interesting to know what materials and tools you would need to refurbish batteries in a real SHTF environment.
 
It would be interesting to know what materials and tools you would need to refurbish batteries in a real SHTF environment.

I have a feeling it's not as complicated as it might seem. Batteries have been a "black box" to many of us for so long that we seldom question what's actually in there. I'm sure what we see in that video is not "ideal", far from it. But I suspect it works well enough on a practical basis, otherwise, I doubt they'd be doing it.
 
The white "plates" are just insulators between the metal plates. Each cell has alternating groups of positive and negative plates that are connected in parallel. With a proper charge you have 2.2 volts at each cell. The positive plates are Lead dioxide and the negative plates are sponge lead. The size and number of plates in each cell give you the discharge capacity (amp/hours) and the number of cells give you voltage. A "12" volt battery has 6 cells for 2.2 volts each. Larger or more plates give higher amp / hour capacity. More space under the plates gives you longer deep discharge rates before the material that falls from the plates causes short circuits in the cell. Deep cycle batteries are typically taller than standard batteries of the same amp / hour capacity. All the plates, in a given battery, have to have the same surface area and weight to give the proper service life.
 
I have a feeling it's not as complicated as it might seem. Batteries have been a "black box" to many of us for so long that we seldom question what's actually in there. I'm sure what we see in that video is not "ideal", far from it. But I suspect it works well enough on a practical basis, otherwise, I doubt they'd be doing it.
He is actually 'rebuilding' the battery with all new plates and is only re-using the case.
At the end of the video you can see the old plate stacks he removed, still sitting beside the case, untouched. I'm sure they get recycled because they are worth money.
Please note, when he washes out the lead sulphate from the bottom of the case and pours it on the ground, you don't wanna do that if you value the water-table underneath. :oops:
I am not an enviro-nazi, but dissolved lead is a persistent toxin that you don't want in your water.
Just ask Flint Michigan.
 
Solid state batteries should start hitting the market sometime in this decade, provided things hold together that long. I for one can't wait after a dozen years living with my own micro grid. In the meantime we buy used batteries from UPS dealers who take them out of places like banks and hospitals every three years. The set we are using now came out of an operating room backup. They are now 5 years old and rated for 20. Only problem is our bank isn't large enough. There was an oops we were supposed to get 1200 +- amp hours at 48V someone messed up and we only got 652 at 48V but even at that it was still a good deal with what we paid.
 
We've alwaays had success with T-105 but not sure we can get them now.Last set lasted 13 years.We buy 5 at a time,haaven't bought any in about 6 or 10 years so don't know what they cost now. He still uses them everyday on golf cart.
 
T-105s are good batteries. I much prefer AGM types myself seeing as they are actually maintenance free. If you ever look really deep into batteries the ones made with 100% virgen lead last the longest and cost the most of the lead acid type batteries. They also have the lowest self discharge rate.
 
I've been using Costco (Interstate) golf cart batteries for a number of years and so far they have given us great performance, I like them because I can run them through a Equalizing charge cycle that AGM types can't take because they are sealed, the equalizing cycle helps clear the sulfite build up from the plates. Our solar controller and the inverter/charger both have the equalizing cycle. All I have to do is check the electrolyte levels, to make sure the cells are well covered. I even bought a distiller to make distilled water to always have it on hand. We have five banks of four batteries in series for 24 volts and 1025 amp-hours. In working with the solar system I installed on our motorhome, I found that I could replace old batteries as long as I installed one each per bank, I'm sure this would work for our backup system, if I had a single battery go bad, I'd do a check on all batteries and pick out the lowest ones in each bank and replace at least one in each bank, just to make sure that the charge system is balanced.
 
Nice thread!
I have a problem mebbe I could get some help with....?

Have an off-grid 650 SF cabin, 6 panels @ 350 W each. (8) 6V batteries. I went with Sealed batteries (AGM) at the time, can't remember exactly why... $225 each x 8 = $2000. They worked great for 3 years and then stopped. I took them back to the battery store and they said that 1 of the cells had failed and that made them all bad. They identified the bad one, and I found a similar used battery and stuck it in the mix...didn't work - they wont hold a charge at all.

I would just buy 1 new one and throw it in but I supposedly cant...?

So I'm not willing to buy 8 more of these if they're so finicky...I'm thinking of getting (8) cheap batteries and see how long they last. Must I get (8) x 6 V or can I get (4) x 12 V ?
Any advice?

PS - Eventually the plan is to get (1) Lithium Ion battery that lasts forever...just spend the big bucks and be done....
 
Way more qualified people will be along shortly...

But in the meantime... ;)

What is the voltage that you need to run what your battery bank is powering? Is it just 12 volt stuff? If so, then you'll need a battery or batteries that can be configured to output 12 volts, whether that's six 2-volt batteries, two 6-volt batteries or some other combination that gets you there. If you're running an inverter, the input voltage of that will pretty much tell you what the voltage of your battery will need to be. Some are 12-volt, some 24-volt, some 48-volt, none wrong, just different.
 
Nice thread!
I have a problem mebbe I could get some help with....?

Have an off-grid 650 SF cabin, 6 panels @ 350 W each. (8) 6V batteries. I went with Sealed batteries (AGM) at the time, can't remember exactly why... $225 each x 8 = $2000. They worked great for 3 years and then stopped. I took them back to the battery store and they said that 1 of the cells had failed and that made them all bad. They identified the bad one, and I found a similar used battery and stuck it in the mix...didn't work - they wont hold a charge at all.

I would just buy 1 new one and throw it in but I supposedly cant...?

So I'm not willing to buy 8 more of these if they're so finicky...I'm thinking of getting (8) cheap batteries and see how long they last. Must I get (8) x 6 V or can I get (4) x 12 V ?
Any advice?

PS - Eventually the plan is to get (1) Lithium Ion battery that lasts forever...just spend the big bucks and be done....
You have to determine if the batteries are wired in series for 48V or or parallel for 6 v.

Check the charge controller configuration and invverter.

From the symptom "will not hold a charge" I would have to guess parallel were a bad cell can drain the others.

Ben
 
Nice thread!
I have a problem mebbe I could get some help with....?

Have an off-grid 650 SF cabin, 6 panels @ 350 W each. (8) 6V batteries. I went with Sealed batteries (AGM) at the time, can't remember exactly why... $225 each x 8 = $2000. They worked great for 3 years and then stopped. I took them back to the battery store and they said that 1 of the cells had failed and that made them all bad. They identified the bad one, and I found a similar used battery and stuck it in the mix...didn't work - they wont hold a charge at all.

I would just buy 1 new one and throw it in but I supposedly cant...?

So I'm not willing to buy 8 more of these if they're so finicky...I'm thinking of getting (8) cheap batteries and see how long they last. Must I get (8) x 6 V or can I get (4) x 12 V ?
Any advice?

PS - Eventually the plan is to get (1) Lithium Ion battery that lasts forever...just spend the big bucks and be done....
If you got 3 years out of AGM's you did good.
We killed them in 2 years in my previous occupation.
The guy is right. When one is toast, the rest aren't far behind. You can change one, and then another and another.... and a year later still have some that will die tomorrow.
If you change to a different type of batteries, change the 'float voltage' in the control.
AGM's run at a higher float voltage that will cook most others so you can't just 'drop in' replacements.
If your system is 24v or 48v you can use 12v batteries if they are wired correctly.
 
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Or 6v in series and parallel for 12v output.

Depending on what your powering .

Jim
Yup

That is another possible configuration.

A dozen years ago I was looking at AGM but after time and reading @viking has said about lead acid, I am leaning toward old school.

Sure I will have to monitor fluid levels and vent the nadty smell when they are charging but until lithium is ready for prime time...

Ben
 
I have 8 lead acid 6v (235ah each)batteries in pairs to produce 12v and that gives me 4 pairs in parallel for output of 930 AH (a 100watt bulb for 930 hours )of power at 12vdc for input to all of my inverters ,12vdc to 120vac output.

Oh ,btw , these batteries are over 10 years old....because I maintain the water level and keep the connections super clean. , And use smart battery tenders to keep them at full charge.

Jim
 
I have 8 lead acid 6v (235ah each)batteries in pairs to produce 12v and that gives me 4 pairs in parallel for output of 930 AH (a 100watt bulb for 930 hours )of power at 12vdc for input to all of my inverters ,12vdc to 120vac output.

Oh ,btw , these batteries are over 10 years old....because I maintain the water level and keep the connections super clean. , And use smart battery tenders to keep them at full charge.

Jim
See that!

Old school is cool if you know what to do and do it.

Ben
 
Okay, I am making a lot of assumptions here:
1) I assume that you have checked the solar panel and charge controller connections and function
2) I am guessing you have 8 6V 225Ah AGM batteries
3) Your setup is a 2Kw solar, I am guessing you are using a 12V 1000 watt inverter
4) your maximum draw is 84 Amps at 12 V,
5) you have your batteries with 4 parallel strings of 2 batteries in series, supplying 12 Volts, so 900 AH of storage @12V

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Okay so here is the rub, if one of the red batteries in series is weak or strong it will create a problem for the other red one....

Here is a nice article on it.

https://rvnerds.com/2017/08/07/electrical-myths-part-3-mixing-batteries-different-agescapacities/
If this is the way your batteries are arranged there are several things you could do:

You could just remove the 2 battery string containing the bad battery(one of the red ones), you would have the 12 Volts you need but your Amp-Hours would be reduced by 25%

If you were going to Gerry-rig it, you might be able to add a 2 new batteries (red) in a string. They would be matched okay but they would be in parallel with the weaker 12V strings, but is kind of okay too. This would give you the 12 volts and maintain the Amp-hours

But like I said I am making a lot of assumptions here, and this would be a hillbilly Gerry-rig approach.

The most important thing to do is make an assessment of which batteries are good and which are bad, make sure that the problem is not in the charge controller or solar panels. If either of these are bad this is a wasted exercise.
 
Thanks to all! Urban Hunter, I'll reply to you as that will answer the others questions as well. I bought the equipment from a solar consultant and installed it myself as I am fairly handy, but I know/understand little of how all this actually works. Forgive my ignorance :) All of y'alls advice is appreciated!
1) I assume that you have checked the solar panel and charge controller connections and function - YES
2) I am guessing you have 8 6V 225Ah AGM batteries - YES
3) Your setup is a 2Kw solar, I am guessing you are using a 12V 1000 watt inverter - SEE PICTURE
4) your maximum draw is 84 Amps at 12 V, 48 V System
Equipment list part 2.PNG
Equipment list part 2.PNG
Solar Equipment list part 1.PNG
Solar Equipment list part 1.PNG

5) you have your batteries with 4 parallel strings of 2 batteries in series, supplying 12 Volts, so 900 AH of storage @12V
 
Batteries.
 

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