LifePO4 GBS Amp Hour Testing 2.5v to 3.6v per cell

[karrak]

What I am saying is that I try to read and understand. I came into this forum mistrustful of Sunking. But I read, and dig, and follow the links that he (and others) post to manufacturer sites and trade sites to see what they're saying, and try to understand what he (and others) say. In a lot of his posts he gives the real calculations that you can do the math for yourself, and look up the formulas for, and see for yourself what he's talking about.

As you say, some of the stuff that Sunking posts is very useful and is correct. IMO if all his posts were useful and correct he would be a real asset to this forum, as it is allot of what he posts is wrong and/or oversimplifies some very complex scenarios. If he is challenged and can't defend his statements he starts making personal attacks and/or changes the subject and/or gets the argument bogged down in the meaning of words and terms. This might work well in a political forum but is not really helpful in a technical forum where we are all trying to learn.

I don't just read here, I read all over the place. And I think that's the key. When other people and sites validate what someone is saying, that gives them credibility.

That is great. Just remember that the person making the post is only going to provide links to other information that backs up their point of view.

Sunking's basic beef with LiFePO4 batteries in a PV environment seems to come down to the line of -- they haven't been documentedly around in PV environments long enough to be able to reliably conclude that they have the long calendar and cycle life that some people have experienced. That doesn't mean that they can't, or don't, but just that there isn't the widespread data to validate that to be the case.

If you made this statement a few years ago I would agree with you, but the evidence that LFP batteries will last at least ten years if treated correctly in a PV environment is piling up, Dax is saying that after 8 years he is seeing hardly any change in performance.

If you look at all the posts that he has made they all tell a consistent story. The information in his posts is backed up by posts from Steve G and Barba on this forum who have batteries over six year old, my batteries which are over three years old and a number of others on the Energy Matters forum who have batteries between 3-4 years old. Compare this to Sunking's raves that Chinese LFP batteries are all a pile of crap and will only last two and a half to five years. If I were in court and had to pick who is the credible (truthful) and reliable(provides correct information) witness I would have to choose Dax over Sunking.

Another factor that maybe more apparent in Australia is that there are now a number of large multinational companies selling LFP and other lithium ion batteries in the retail market for use in PV environments. These companies are offering offering ten year warranties on their products.

Simon

[karrak]

Let's define Floating a Battery for you. It is something every DC Power person know and is the basic fundamental operation of all battery systems. Soething every pro knows except you Dax. .

Floating a Battery

Holding a battery at some predetermined voltage or SOC and allowing the charge source (rectifiers, power supply, charge controller or whatever) to supply power to the loads while the battery remains floating and ready to take over in the event the power fails or the sun sets on your solar system.

You are micro-cycling your batteries many times a day causing excessive wear. Everyone else knows to Float the batteries and let the solar panels provide power to the loads after the batteries are charged up. You are the only solar person in the world who does not know that. You do not have a clue what is going on and very evident. Not even Karrak will defend you and knows to Float his battery just like I do and have been saying. Karrak is just to stubborn to admit I am right and he does exactly what I say. Charge them up to some point and hold. That means FLOAT. It is just a Voltage that uses CC/CV like any battery charger.

Sorry Sunking, you are wrong and you are contradicting yourself in this post. I agree with Dax.

From what I have read, Dax charges his LFP batteries to 3.5V/cell(14V on 12 volt battery) then stops charging and lets the battery discharge down to 3.4V/cell(13.6V) where he starts charging back up to 3.5V/cell again, as you say he is micro-cycling the battery, this is different from floating the battery. The definition you have given states "Holding a battery at some predetermined voltage or SOC" . He is not doing this. Either you don't understand or you are just playing games, which is it?

On the subject of micro-cycling causing excessive wear, from the research I have done I don't think this is the case. The wear on the battery is more dependent on the total number of Ah going through the battery rather than the number of cycles. Doing 10,000 cycles at 9% or 1,000 cycles at 90% gives roughly the same wear even though the amount of energy cycled through the battery is the same. I am happy to debate this and am always interested in getting more information on this subject.

I do not "Charge them up to some point and hold", I charge to 3.45V/cell(13.8V) at an end charge current of C/50 then drop and hold the voltage at 3.35V/cell(13.4V) i.e. I float my battery at 3.35V/cell. If we call 3.45V/cell @C/50 100%SOC, dropping the voltage to 3.35V/cell results in a lower SOC of 99%-98% at the end of the day. From my understanding of the mechanisms that cause "wear" of LFP batteries I don't think my approach will make much difference to the approach that Dax takes. I am happy to be proved wrong about this and am alway interested in further information.

Simon

[Sunking]

Yet everything on this site is in the USA including suppliers. Nothing Aus about anything here.

Pay attention, USA is #1.

Let's define Floating a Battery for you. It is something every DC Power person know and is the basic fundamental operation of all battery systems. Soething every pro knows except you Dax. .

Floating a Battery

Holding a battery at some predetermined voltage or SOC and allowing the charge source (rectifiers, power supply, charge controller or whatever) to supply power to the loads while the battery remains floating and ready to take over in the event the power fails or the sun sets on your solar system.

You are micro-cycling your batteries many times a day causing excessive wear. Everyone else knows to Float the batteries and let the solar panels provide power to the loads after the batteries are charged up. You are the only solar person in the world who does not know that. You do not have a clue what is going on and very evident. Not even Karrak will defend you and knows to Float his battery just like I do and have been saying. Karrak is just to stubborn to admit I am right and he does exactly what I say. Charge them up to some point and hold. That means FLOAT. It is just a Voltage that uses CC/CV like any battery charger.

[Sunking]

As for floating a battery, there is nowhere I can find anywhere on the net that agrees with sunking that a battery disconnected from charge is classed as floating. It is inly floating when a charge is input to compensate for the natural and dramatic lose you find in lead acid.

I rest my case you rhonor. Dax has no clue what Floating a battery is. Even Karrak knows what Floating a battery means

[Sunking]

I never said that I read all of your posts. Just other posts...



Dude, I'm not trying to attack you. I'm just saying -- from the stuff I have read, you haven't done anything but spout numbers and claims about your experiences and systems and word-of-mouth customers, but haven't backed any of your claims with hard data - no charts, graphs, pictures, logs, websites, newspaper/magazine articles, nothing :/ If I'm wrong and have missed them, please show me, don't just chop me down and call me ignorant. Put yourself in my shoes - would you trust what you're saying based on the amount of third-party-verifiable data that you've provided? .

Smiley he cannot produce anything to back himself up. He has clearly and loudly said he knows nothing about electricity or batteries. He is so ignorant he does not even know he admitted it when he said he DOES NOT COMPREHEND MATH. He cannot even balance a check book. You cannot be an engineer, technician, designer, or even a carpenter without good math skills.

So Dax since because I am such a nice guy and teacher I came up with something that might help you understand Ohm's Law. It is 12 equations and governs what goes on inside any battery. Since you have no math skills perhaps a picture will help you understand.

[smily03]

How do you know that what Sunking is saying is truthful and correct and that he understands what he is commenting on? Unless you have a technical understanding of what he is writing about you don't. You take it on good faith that he is not lying to you and does know what he is talking about.

You're right, I don't have a technical understanding of it. And I don't understand all of the details and nitty-gritty. And I'm not saying that Sunking is infallible, or that other people's views and experiences aren't true or valid.

What I am saying is that I try to read and understand. I came into this forum mistrustful of Sunking. But I read, and dig, and follow the links that he (and others) post to manufacturer sites and trade sites to see what they're saying, and try to understand what he (and others) say. In a lot of his posts he gives the real calculations that you can do the math for yourself, and look up the formulas for, and see for yourself what he's talking about.

I don't just read here, I read all over the place. And I think that's the key. When other people and sites validate what someone is saying, that gives them credibility.

Sunking's basic beef with LiFePO4 batteries in a PV environment seems to come down to the line of -- they haven't been documentedly around in PV environments long enough to be able to reliably conclude that they have the long calendar and cycle life that some people have experienced. That doesn't mean that they can't, or don't, but just that there isn't the widespread data to validate that to be the case.

It's kind of like, my grandpa's car had over 500,000 miles on it when he finally got rid of it. That was his experience, and it was legitimate. Does that mean that all Oldsmobile cars will get over 500,000 miles if taken care of? Not necessarily. His did. But that doesn't mean that you can safely conclude that all will, based on the experience of one person, or a few people.But if it was determined that a majority of Oldsmobile cars get over 500,000 miles, then yes, it would be a valid conclusion that can be backed by numbers.

The data has to back up the claims. Otherwise, the claims are just that -- claims. But once the data is there to back it up, then that changes the game.

Again, I'm not trying to do anything more than say -- I've followed the hype in the past, and gotten burned. So I'm skittish and more cautious now. I want to believe that there's something better than FLA, both for cycle and calendar life, and lower maintenance. But until there is a good amount of verifiable real-world data to back those claims in this specific application, I'm going to stick to what's known to work. I don't have near enough money to chase fantasy products that don't pan out in the long term.

[SunEagle]

I never said that I read all of your posts. Just other posts...



Dude, I'm not trying to attack you. I'm just saying -- from the stuff I have read, you haven't done anything but spout numbers and claims about your experiences and systems and word-of-mouth customers, but haven't backed any of your claims with hard data - no charts, graphs, pictures, logs, websites, newspaper/magazine articles, nothing :/ If I'm wrong and have missed them, please show me, don't just chop me down and call me ignorant. Put yourself in my shoes - would you trust what you're saying based on the amount of third-party-verifiable data that you've provided?

You could be totally legit and on the cutting edge of the technology. But for what it's worth, I could just as easily say that I have a ton of customers and this amazing system, but without something to back it - something - anything - it's just words. So please forgive me for being skeptical, but I don't know you from Joe Schmoe.

If you look at the bottom of karrak's posts you will see the hardware he uses. He has 32 x 90ah batteries that are LiFeYPO4 made by Winston. But he does mention a homemade BMS whatever that is. I am not sure exactly what Dax makes or uses but I would think something similar to the Winston.

[smily03]

dax -- from reading this and other posts

I never said that I read all of your posts. Just other posts...



Dude, I'm not trying to attack you. I'm just saying -- from the stuff I have read, you haven't done anything but spout numbers and claims about your experiences and systems and word-of-mouth customers, but haven't backed any of your claims with hard data - no charts, graphs, pictures, logs, websites, newspaper/magazine articles, nothing :/ If I'm wrong and have missed them, please show me, don't just chop me down and call me ignorant. Put yourself in my shoes - would you trust what you're saying based on the amount of third-party-verifiable data that you've provided?

You could be totally legit and on the cutting edge of the technology. But for what it's worth, I could just as easily say that I have a ton of customers and this amazing system, but without something to back it - something - anything - it's just words. So please forgive me for being skeptical, but I don't know you from Joe Schmoe.

[karrak]

Without something to go off of beyond words in a forum, we don't know you from Joe Schmoe from Timbuktu. I'm not trying to be arrogant, or rude, or mistrustful, or anything like that, but all the vagueness and obscurity just makes it seem like you're trying to hide something.

How do you know that what Sunking is saying is truthful and correct and that he understands what he is commenting on? Unless you have a technical understanding of what he is writing about you don't. You take it on good faith that he is not lying to you and does know what he is talking about.

I have got far more useful information from posts by Dax, Barba and Steve G Willy T and others on other forums who have experience with LFP batteries in off-grid systems and don't have an axe to grind than from anything that Sunking has posted. Dax, like me and others who have swapped from lead acid or aging nickel cadmium batteries in their off-grid systems to LFP batteries understand just how much better LFP batteries are.

Simon

Off grid 24V system, 6x190W Solar Panels, 32x90ah Winston LiFeYPO4 batteries installed April 2013
BMS - Homemade Battery logger github.com/simat/BatteryMonitor
Latronics 4kW Inverter, homemade MPPT controller

[dax]

Who wants to break the news to Dax this is an Austailian Owned and Operated and SK has the majority of the tutorial Stickies and write solar practices for industry. Geez dude you do not even know what Floating a battery means.

Yet everything on this site is in the USA including suppliers. Nothing Aus about anything here.

[dax]

Then you haven't read my posts as you claim, I've already pointed out we have no website, simply because we don't need one. All our custom comes from word of mouth referrals and all the details of our systems, except the controlling electronics has been revealed. My kids keep hassling me for a website, but we had one 3 years ago and it was a waste of money, that got us no orders and as we don't retail, no need. No way would reveal what keeps us growing our business, we like to be in front and those ridiculing me, are simple revealing where their mentality really lies and the veracity of their claims.

As for floating a battery, there is nowhere I can find anywhere on the net that agrees with sunking that a battery disconnected from charge is classed as floating. It is inly floating when a charge is input to compensate for the natural and dramatic lose you find in lead acid. Making that claim would mean every battery not connected to a charge, is floating even if it sat for 3 years. When the facts are it is discharging and can only float with a compensating charge to maintain it is used.

Lifepo4 in the first 5 years used properly, lose nothing and after 8 years, in our experience, loses just under 1%. Try leaving a lead acid battery sitting off charge and see what you end up with, dead. Unless you are using hot air o maintain it, just like sunkings brain

[smily03]

dax -- from reading this and other posts -- could you please give us details about your company and products, rather than alluding to them? A lot of the confusion, conflict, and doubt could be eliminated if you just gave links to product literature, a website, a name, something. Without something to go off of beyond words in a forum, we don't know you from Joe Schmoe from Timbuktu. I'm not trying to be arrogant, or rude, or mistrustful, or anything like that, but all the vagueness and obscurity just makes it seem like you're trying to hide something.

[SunEagle]

Let's see I live in Panama, currently in Rio watching the games as a consultant Engineer,, and travel the world.




Who wants to break the news to Dax this is an Austailian Owned and Operated and SK has the majority of the tutorial Stickies and write solar practices for industry. Geez dude you do not even know what Floating a battery means.

Isn't that the opposite of a boat anchor?

[Sunking]

very simple inadequate programming and have probably never been outside your country. It's drop kicks like you that make it difficult for those looking for understanding of this new technology and all you can do is abuse, pathologically lie and have the brain dead audacity to try to change the meanings of world accepted meanings to suit yourself.

Let's see I live in Panama, currently in Rio watching the games as a consultant Engineer,, and travel the world.

If you were on an Aus forum they'd have thrown you out years ago, we don't stand for morons, who abuse, lie and make pathetic infantile claims. .

Who wants to break the news to Dax this is an Austailian Owned and Operated and SK has the majority of the tutorial Stickies and write solar practices for industry. Geez dude you do not even know what Floating a battery means.

[dax]

Where do you get these insane delusions from, quote where I have suggested an energy pack 10 times larger than required to do a job. You make up the most insane lies I've ever seen, especially as you have no knowledge about anything, out side your very small window of experience, very simple inadequate programming and have probably never been outside your country. It's drop kicks like you that make it difficult for those looking for understanding of this new technology and all you can do is abuse, pathologically lie and have the brain dead audacity to try to change the meanings of world accepted meanings to suit yourself.

If you were on an Aus forum they'd have thrown you out years ago, we don't stand for morons, who abuse, lie and make pathetic infantile claims. Yet you have no experience or knowledge in the manufacture and use of off grid lifepo4 systems in any way, which further proves the state of your lack of veracity. But when you look at the state and beliefs of your country, it's understandable and I feel so sorry for the decent people in the USA being brought down by low life like you.