Extending a part worn battery bank

Short_Shot said:

Alright kids.

You both have big PPs, equal stream height and distance, and your moms say you're both handsome.

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Mine is small. But I'm happy with it.

xNYCMarc said:

Why? You're already questioning it's existence to the point where you tried to insinuate that the school doesn't even have a science program. I tune people like that out. If you disagree with my findings about the batteries, that's fine. But don't attack my education.

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I think you are hyper-sensitive, I did not attack your degree but rather just asked what I was it because the degree doesn't seem to specify that.

Posplayr said:

I think you are hyper-sensitive, I did not attack your degree but rather just asked what I was it because the degree doesn't seem to specify that.

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I would add too that a general mech E degree doesn't specialize in anything and means nothing about qualifications in a given field without years of work experience related to it.

Anyone with an education should understand this already.

You come out with enough knowledge to pick a field and start learning, but are not an expert on anything they teach, even if you specialized, until a masters level at minimum and most of them will agree by that point that they still have much I learn.

So like in my case I'm in plastic injection molding.

I know a bit about designing and specifying equipment, sizing electrical/pnuematic/hydraulic/heat loads and storage capacity, heat transfer, turbulent flow, non-newtonian fluids, and most of all plastic injection processing....

But I am by no means an expert at anything other than the actual melt processing (and I'd be a fool to claim I'm the authority on the matter), despite my generalized education on all of those things.

When I need an expert, I call one who gets paid very well to be that expert.


Somewhat back to the point, even an EE would be much better suited for the discussion but it's quite possible that an accomplished electrical engineer may even have zero experience on this exact specific topic of batteries.

So even further to the point, it's not exactly an invalid question to ask if one is specialized in the field of energy storage because "engineering degree", while a respectable accomplishment of course, does not mean much in its own right when it comes to a specific topic.

As before, I know a little about a lot of things. But I'm not an expert on 99% of the things I've dabbled in.

And at the end of the day nobody is posting anything technical enough to warrant this stupid debate about education in the first place. What has been posted is little more than an opinion piece, followed up by opinions, and a whole bunch of chest beating about how that opinion is better.

I have two sets of L-16 large format batteries, one Rolls Surette S-530 L-16 400 a.h. Solar duty deep cycle and one set Interstate (rebadged US Battery) L-16 426 a.h. floor sweeper duty, they do not like to be in parallel period...one will be too low s.g. and the other will boil.

Rolls Surette’s lead engineer told me directly that I should keep them separate as they are NOT THE SAME ,
Interstate’s Lead foreman at the Salinas Ca. plant said the same thing

The s.g. are not the same 1.277 for the Interstate and 1.265 for the Surette’s the charge voltages are not the same 28.8 for the Interstate and 30.0 for the Surette

To that end I have two fully programmable separate charge controllers, MidNite Classic ,separate battery monitors etc. Bogart Engineering Tri-Metric These are kept totally seperated. Grounds are tied together but one bank is used at a time
Its not that I need that much capacity at a time, But I have a difficult water pump down 420 feet with a water level of -250 to -350 feet, so pretty much a big load if i'm in the coastal fog for days and cant get at least 50 amps charge

When you buy a set of Rolls Surette batteries they are made on the same day ,by the same tech, and have sequential serial numbers and shipped as a “matched set” with instructions not to attempt to “mix and match”
This system has been in use for 16-17 years now with no issues at all the Surette’s came out the door 2 26 2005, the Interstates are about 6 months older

In 1965 when I was Uniuersity of Alaska in Fairbanks Alaska I paid my way through college working at Alaska Husky Battery where we built Flooded Lead Acid Arctic batteries much thicker plates than any normal car battery with the hottest acid i have ever seen in a FLA 1.320....these were Arctic batteries to be used in the winter only. They would not survive the Arctic summer 80-90 F in Fairbanks under the hood.....way too hot for such a hot battery, just like your snow tires, keep them in the barn for the summer, save them for next winter.
When a customer need one battery for a two battery setup it was sold with a very restricted warranty as the old one will drag down the new one and it will fail prematurely....every time. finally they would not sell you one.

The US Employment Prevention Agency (EPA) ran Alaska Husky Battery out of business....for a while, they are now in Moscow, Russia making the same battery for the Russian Arctic
Deka is another very high end battery producer who insists on selling the set....same reason

Thats 4 battery manufacturers who do not recommend mixing batteries. I have never heard of any battery manufacturer who recommends mixing new with aged batteries or dissimilar types of batteries

Let me see 1965 to 2021 thats 56 years lead acid expereince that says FLA is not a mix n match.

Obviously I do not beleive a word of what someone is saying


But i dont know nada.....

29 years engineer at General Electric Corporation DC to microwave , 20 years electric contractor, 50% owner of auto repair shop, Interstate dealer (the shop, not me personally)

You cant argue with someone who knows everything, not even worth the time.....

So your professional opinion is that you can do it, you generally shouldn't do it if you can help it, and that if you do so you should be prepared for long term issues?

Ya got it, very rarely i will be forced to parallel my sets, but I allways seperate the systems so they can recharge to their own settings.

In my shop you can not buy one battery for your 2 battery diesel truck, I do not like having to deal with the warranty issue. You need one there is kmart, cosco, but dont ask me to work on it. I only do severe electrical problems, mostly a silent partner but im the electrical wizard

I have one good case for using mismatched batteries, You are up bear creek road on the side of the mountain , its raining cats and dogs, the mud is getting deep, wind is howling and you need to get home...and that is all you have!
And oh ya, the lightning bolts are getting closer.....

Tecnodave said:

Ya got it...!

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Seems to me like the thread should be considered solved at this point to avoid further phallus waving.

Agreed.....

Short_Shot said:

I would add too that a general mech E degree doesn't specialize in anything and means nothing about qualifications in a given field without years of work experience related to it.

Anyone with an education should understand this already.

You come out with enough knowledge to pick a field and start learning, but are not an expert on anything they teach, even if you specialized, until a masters level at minimum and most of them will agree by that point that they still have much I learn.

So like in my case I'm in plastic injection molding.

I know a bit about designing and specifying equipment, sizing electrical/pnuematic/hydraulic/heat loads and storage capacity, heat transfer, turbulent flow, non-newtonian fluids, and most of all plastic injection processing....

But I am by no means an expert at anything other than the actual melt processing (and I'd be a fool to claim I'm the authority on the matter), despite my generalized education on all of those things.

When I need an expert, I call one who gets paid very well to be that expert.


Somewhat back to the point, even an EE would be much better suited for the discussion but it's quite possible that an accomplished electrical engineer may even have zero experience on this exact specific topic of batteries.

So even further to the point, it's not exactly an invalid question to ask if one is specialized in the field of energy storage because "engineering degree", while a respectable accomplishment of course, does not mean much in its own right when it comes to a specific topic.

As before, I know a little about a lot of things. But I'm not an expert on 99% of the things I've dabbled in.

And at the end of the day nobody is posting anything technical enough to warrant this stupid debate about education in the first place. What has been posted is little more than an opinion piece, followed up by opinions, and a whole bunch of chest beating about how that opinion is better.

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The thing is that the question of "Which degree do you have so we can determine what your expertise is" wasn't asked. What was said and implied was "hey, your school doesn't even offer the program that you supposedly earned a degree in", which if true would be a "gotcha" moment that I wasn't authentic. But it was said without even doing a basic check to see if it was even true, which I showed obviously wasn't true. That's what I have a problem with.

Amen

Short_Shot said:

Seems to me like the thread should be considered solved at this point to avoid further phallus waving.

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There never was any "phallus" waving. People are also confusing parallel strings with parallel cells. But I'm done arguing. It isn't worth it.

Wellbuilt said:

Amen

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Praise be unto the flying spaghetti monster.

There was no phallus waving. There was some degree waving and it was hilarious. I am perfectly willing to grant that Mark has a degree. That doesn't mean anything to me in regards to this discussion. As I said earlier, I have known folks with degrees who knew nothing and folks without who were very knowledgeable. Let's forget the degrees. As the Borg would say, degrees are irrelevant.

As a topic for discussion on a DIY solar site, this is a good and important one. Mark, you have yet to post anything supporting your claims. I for one am still open to evidence. Nor have you answered any of the points that have been brought up. You haven't even told us the details of your experiments.

So Mark, what happens in this situation: You put two lead batteries in parallel. One is only capable of reaching 1.22 SG. The other is capable of reaching 1.28. When charging them, when you get to max charge voltage, what will be happening to the older battery? Then, after the sun has gone down, the new battery has a higher level of charge then the old battery. What happens to its level of charge? Then somebody fires up a heavy load. Maybe some midnight welding. Which battery is providing more of the power?

As I said earlier, I have seen this aging process in action on multiple occasions. At first the new battery will read higher, for a couple or few weeks. Then it will read the same as the rest of the bank. At that point if taken out of the bank and charged it will manage to charge fully. If left in the bank longer, for a few months, it will no longer be able to charge fully and will charge to the same extent as the average of the bank. I have seen and measured it.

boondox said:

There was no phallus waving. There was some degree waving and it was hilarious. I am perfectly willing to grant that Mark has a degree. That doesn't mean anything to me in regards to this discussion. As I said earlier, I have known folks with degrees who knew nothing and folks without who were very knowledgeable. Let's forget the degrees. As the Borg would say, degrees are irrelevant.

As a topic for discussion on a DIY solar site, this is a good and important one. Mark, you have yet to post anything supporting your claims. I for one am still open to evidence. Nor have you answered any of the points that have been brought up. You haven't even told us the details of your experiments.

So Mark, what happens in this situation: You put two lead batteries in parallel. One is only capable of reaching 1.22 SG. The other is capable of reaching 1.28. When charging them, when you get to max charge voltage, what will be happening to the older battery? Then, after the sun has gone down, the new battery has a higher level of charge then the old battery. What happens to its level of charge? Then somebody fires up a heavy load. Maybe some midnight welding. Which battery is providing more of the power?

As I said earlier, I have seen this aging process in action on multiple occasions. At first the new battery will read higher, for a couple or few weeks. Then it will read the same as the rest of the bank. At that point if taken out of the bank and charged it will manage to charge fully. If left in the bank longer, for a few months, it will no longer be able to charge fully and will charge to the same extent as the average of the bank. I have seen and measured it.

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My name isn’t Mark. I already terminated my discussion with you earlier and the fact that you can’t even respect someone enough to get their name right shows that I was right to terminate. As I said earlier, I gain no benefit from changing your mind. I don’t make any money from it, I’m not selling anything. So again, believe what you want. It’s won’t change my life. This particular part of the discussion wasn’t even involving you. You didn’t incorrectly say that my school didn’t offer the program that I earned my degree in. Someone else did.

xNYCMarc said:

My name isn’t Mark. I already terminated my discussion with you earlier and the fact that you can’t even respect someone enough to get their name right shows that I was right to terminate. As I said earlier, I gain no benefit from changing your mind. I don’t make any money from it, I’m not selling anything. So again, believe what you want. It’s won’t change my life. This particular part of the discussion wasn’t even involving you. You didn’t incorrectly say that my school didn’t offer the program that I earned my degree in. Someone else did.

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I beg your pardon for getting your name wrong. My intent was to show respect by using your name.

However, yet again you make no logical argument. You bring no evidence to the table. You don't discuss the arguments that have been presented. You simply continue to maintain you are right.

Have you considered that the possible benefit you might gain is learning something, that you just might possibly be wrong? I have considered that possibility for myself and if you bring the slightest shred of evidence I will consider it with an open mind.

boondox said:

I beg your pardon for getting your name wrong. My intent was to show respect by using your name.

However, yet again you make no logical argument. You bring no evidence to the table. You don't discuss the arguments that have been presented. You simply continue to maintain you are right.

Have you considered that the possible benefit you might gain is learning something, that you just might possibly be wrong? I have considered that possibility for myself and if you bring the slightest shred of evidence I will consider it with an open mind.

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I did discuss the topic presented. Just because you disagree doesn’t make me “not discussing the topic”. People are also conflating the issue of “parallel STRINGS” and “parallel CELLS” in a single string. My argument is about parallel cells in a single string. But people keep arguing about “sets” and “strings” and such that aren’t matching what I’m talking about.

You have been asserting your position but not explaining why you think it to be true.

As far as I know, alkaline batteries are the only common type of batteries that are made of a single cell. All of the other batteries we use are series of cells. With lead, each cell is 2V and usually are manufactured such that there are 3 or 6 cells in series. There are exceptions, fork lift batteries can be 2V and I think are usually placed in series only but I haven't worked with them much.

Perhaps define what you mean by parallel strings and parallel cells with examples of each.

Not taking sides. So helping my cheap old "parallel FLA marine's" is impossible?

circus said:

Not taking sides. So helping my cheap old "parallel FLA marine's" is impossible?

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We'd need more information. But if you are asking can you add some new batteries to your old ones I don't think it is a good idea. Nor does the battery manufacturing industry. If you have both the courage and time, read through the thread.

circus said:

Not taking sides. So helping my cheap old "parallel FLA marine's" is impossible?

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I'm no expert but from everything I've read about adding to my Gel battery bank I'd say it's not a good idea to add new lead to old.
There is one disagreeing opinion but it's not enough for me to bet battery money on.

circus said:

Not taking sides. So helping my cheap old "parallel FLA marine's" is impossible?

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My position is that it is very possible. But obviously others are disagreeing with me. My findings are that two (or more) paralleled cells will function as a single cell. If there is a “weaker” cell in that parallel “block”, then the “stronger” cell will simply “do more of the work”, but less than if the cell were by itself and not paralleled with another cell. But again, people are disagreeing with me about that.

boondox said:

You have been asserting your position but not explaining why you think it to be true.

As far as I know, alkaline batteries are the only common type of batteries that are made of a single cell. All of the other batteries we use are series of cells. With lead, each cell is 2V and usually are manufactured such that there are 3 or 6 cells in series. There are exceptions, fork lift batteries can be 2V and I think are usually placed in series only but I haven't worked with them much.

Perhaps define what you mean by parallel strings and parallel cells with examples of each.

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I’m going to do a set of engineering drawings and submit it to Rolls/Dekka/several manufacturers and ask if they see a problem and would warranty their cells in that configuration. Hopefully I will get a clear “no way” or “we see no problem” and “yes, we would warranty the cells”.

xNYCMarc said:

I’m going to do a set of engineering drawings and submit it to Rolls/Dekka/several manufacturers and ask if they see a problem and would warranty their cells in that configuration. Hopefully I will get a clear “no way” or “we see no problem” and “yes, we would warranty the cells”.

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That would be great! I really am curious as to the truth of the matter. Please post the drawing here so we can look at it. We may all be talking at cross purposes.

xNYCMarc said:

My findings are that two (or more) paralleled cells will function as a single cell. If there is a “weaker” cell in that parallel “block”, then the “stronger” cell will simply “do more of the work”, but less than if the cell were by itself and not paralleled with another cell.

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Yes. So in doing more of the work, it ages until it is at the same point as its neighbor, when they both start doing equal work. Work ages a cell. More work ages it more. We also run into problems in the charge side of the cycle. One battery has reached as full of a charge as it can. The other is still charging. So the weak cell boils. Once charge is complete for the day, even if there is no load, the stronger battery will attempt to charge the weaker battery because the charge seeks to reach balance. Since the weak battery can't accept more charge the energy is wasted as heat. Now the stronger battery sits over night at a lowered state of charge until the next charging cycle begins. This of course leads to increased sulfation, one of the primary aging factors of lead batteries.

boondox said:

That would be great! I really am curious as to the truth of the matter. Please post the drawing here so we can look at it. We may all be talking at cross purposes.

Yes. So in doing more of the work, it ages until it is at the same point as its neighbor, when they both start doing equal work. Work ages a cell. More work ages it more. We also run into problems in the charge side of the cycle. One battery has reached as full of a charge as it can. The other is still charging. So the weak cell boils. Once charge is complete for the day, even if there is no load, the stronger battery will attempt to charge the weaker battery because the charge seeks to reach balance. Since the weak battery can't accept more charge the energy is wasted as heat. Now the stronger battery sits over night at a lowered state of charge until the next charging cycle begins. This of course leads to increased sulfation, one of the primary aging factors of lead batteries.

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"more work ages the cell" so according to you (and what I've been saying) less work ages the cell less. So how is it worse to have two cells doing less work than having one cell doing all the work?
"We also run into problems in the charge side...." This is the fundamental misunderstanding. One cell will not be at a lower state of charge. Just like during discharge, one cell is doing "more work", the same is true during charging. The "stronger" cell will be taking more of the charge current. You can stop the charge at any given point and the SOCs of both cells will be roughly the same.

xNYCMarc said:

"more work ages the cell" so according to you (and what I've been saying) less work ages the cell less. So how is it worse to have two cells doing less work than having one cell doing all the work?
"We also run into problems in the charge side...." This is the fundamental misunderstanding. One cell will not be at a lower state of charge. Just like during discharge, one cell is doing "more work", the same is true during charging. The "stronger" cell will be taking more of the charge current. You can stop the charge at any given point and the SOCs of both cells will be roughly the same.

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Of course, the bank will be propped up a little longer with adding a new battery to the bank. That is (I think) in my very first post in this thread. But, if the old batteries are pretty beat and the new battery quickly drops to the same capacity of the old batteries it is not worth it. As I have said, I will do a replacement if the old batteries are still reasonably strong. But that is rare. Most cells do not fail in the first 20% of their lifespan. And it is most often a single cell that starts the problem.

Yes, one cell will be at a lower state of charge. Again, I have measured it many times. The old battery reaches the maximum charge it is capable of holding. The new battery has not and continues to charge. Once a lead battery has reached the max it is capable of it simply won't go higher. You can charge it all day and it won't achieve 1.28 or whatever the max for that battery is. It just starts to cook. This isn't really a problem as long as it is a flooded battery and you replace the water. It does drop your charge efficiency but with most systems you will never know or care. But no matter what you do you cannot make the maximum SG of a battery improve once it has lost capacity. If you could you could keep batteries alive forever.

Here is another example. I replaced my FLA bank last year. Four of the batteries were hotter than the others. It would have cost too much to ship them back to the manufacturer and they were being a PITA so I just ate it. I tried everything I could, repeated EQ's, long absorb times and so on. Nothing would bring the weaker cells up. I just had to add more water than usual. And within a month or so the hot batteries read the same as the others. As was noted earlier in the thread, best practice is to get cells from the same date and even better sequential serial numbers. I live in the middle of nowhere and the nearest place to buy batteries is 2.5 hours away one way. I was busy and decided to take a chance on having batteries delivered and I got burned. Next time I will find a way (if I use lead, hopefully next time LFP) to go and pick them up in person and test before I pay.