Charging efficiency LifePO4

[SunEagle]

We have installed and sold over a hundred of our chargers here in Aus, NZ, PNG and Indonesia, there is also a really good lifepo4 solar charge controller now being produced in NZ, which is just like ours. The understandable problem is, it's very hard for people to get out of the lead acid mind set and look at lifepo4 from a very different perspective and the only way you can do that is be experimentation and real hands on use with big and small systems. We've spent many years working with these and it was only a couple of years ago we made the break from lead acid mentality to lifepo4, the results have been great and now we don't even need a cumbersome BMS. We use simple raspberry Pi's running linux to control our pack enclosure temperatures and to control outputs from individual banks in the pack, which again improve the performance of the system. In fact everything in our business runs on linux, which is 21st century technology and we get the same thing from those trapped in last century junk windows and apple. But they can't do what we can and like all fools, run our computer ans off grid systems down. Now we are getting solar and battery retailers inquiring about our systems and chargers. We don't even advertise, nor have a website, all our work comes from customer referral which is all the acceptance we need.

Of course those programmed in the past century approach are extremely reluctant to change, our engineers had great trouble accepting my idea's for this and everyone I spoke to with qualifications said it wouldn't work. Once our engineers put a test one together and tried it for a few days, they changed their minds and now are refining and making it better by developing it so it charges individual cells.

I'm lucky, not trapped in last century technology programming. so didn't find it hard to look at the situation and work out we needed something that just charged bulk inputs and stopped when it reached a set point. Then started bulk recharging at a point where it was not cycling.

Lifpeo4 handles it easily, everyone with real knowledge agrees they can take big charges and don't like floating or other last century settings and we have proved that in our own workshop and the field. So we have not invented anything, just put together all the facts to make something that suits the situation. With just a small amount of research throughout the industry, you will find we have done what the technology needs, according to all the information and nothing special.

I would add that getting out of the FLA thinking also requires someone to compare the costs. Based on all existing data a Lifepo4 chemistry battery costs a lot more up front then quality FLA batteries. While your charger may allow the Li battery to get a longer life the final cost / kWh being generated by that battery is the final determination to go that way or another.

Since both you and karrak are technically neighbors you both share the high cost and low reliability of grid power. So it is an easy sell for your area and the other areas you mention. But when it comes to most of the US and Canada going with any lithium battery would not be cost effective for a home owner. The POCO's might be able to afford those systems by not the average guy down the street.

As for my thinking being old and "trapped" in the last century, that is something stated by people that have no understanding or patience of their parents generation. Making that type of statement does not win you any friends. I should know since I did the same when I was in my 20's but grew up and got to know my father's generation ideas so I could find ways to make technology better. I believe I have made a difference with my 40 plus years of electrical engineering experience but I choose not to brag about it.

So I look forward to actually seeing your charging system hardware and how it works with lifepo4 batteries. I hope it is a breakthrough but again it still comes down to cost.

[Sunking]

Sunking, do you really have to try so desperately to change the definition of floating a battery, a battery to float requires an input which compensates for the natural loss of a lead acid battery, not switching of charge and letting it sit. If you let a lead acid battery sit with no float charge, it will lose energy and is not floating, but naturally draining, float keeps it at its optimal charge.

Could not agree with you more. Does the same thing for lithium. Your is charged to 14.0 volts. When charged you lower voltage to 13.6 and Float your battery. That is what ever 2-Stage battery charger does. Every solar charge controller makes them that way. Better units have 3rd and 4th stages. All you got is a plane jane 2-stage charger.

You have no clue what you are talking and each time you open your mouth you stick your foot in deeper and show everyone you have no idea how a battery charges. You are lost between a Marketing Term like Float Charger and a Technical term like Float Mode.

How do you charge a battery?

Very simple apply a Set voltage until the current tapers to 3 % of it C spec. Makes no difference if it is a lead acid battery or Lithium, they use the exact same voltage of 14.4 volts. When the current tapers you reduce voltage to maintain capacity and allows the charger to run the loads while the sun is shinning saving your batteries. You lower the voltage to 13.6 volts for either FLA or LFP. You do not have anything specials, just a 2-stage charger and you do not have a clue how it works or how any battery charges. You already admitted you do not know. If you cannot do and understand the math, you cannot understand the laws of physics.

[dax]

Sunking, do you really have to try so desperately to change the definition of floating a battery, a battery to float requires an input which compensates for the natural loss of a lead acid battery, not switching of charge and letting it sit. If you let a lead acid battery sit with no float charge, it will lose energy and is not floating, but naturally draining, float keeps it at its optimal charge.

lIfepo4 is the opposite and has very negligible loses and they happen over years, not hours or days, If your lifepo4 pack uses the proper voltages, bulk charging, is balanced and within a controlled environment, it functions excellently. As for balancing, our method works and that's what counts. Personally couldn't give a stuff what others do, but 8 years of no failures and more than 2 years using our own charge controllers with not problems along with increasing installation bookings and sales, is all we need to know we are on the right track.

Are you so desperate you have to demand what I post is something else, as in claiming our chargers charge to 14v, then slip back to charging at 13.6v. Surely you have just a little bit of a functioning brain to realise that is an absurdly stupid claim, nothing could be farther from the truth and it makes no sense. Our charge controllers, both solar and 240v are single stage, bulk and nothing else.

You really are a great laugh, but sadly those reading these forums to try to get some idea of where solar and lifepo4 sits, will get confused as you contradict yourself and try to cover up you're never ending changes in definitions and absurd claims.

[dax]

I think understand it a little better. Thanks for the explanation.

All I ask in return is that while you and some others may have found a better mouse trap to charging lifepo4 batteries the technology is still not widely known and may come under the microscope of doubt.

Understanding that logic is also not rocket science.

People that have technical experience are not easily swayed by advertising glitz and false promises. We need hard facts that help us understand what is being presented as being truthful. Until your technology becomes more mainstream and available you might have an uphill road convincing people to believe in it or even harder to purchase it.

We have installed and sold over a hundred of our chargers here in Aus, NZ, PNG and Indonesia, there is also a really good lifepo4 solar charge controller now being produced in NZ, which is just like ours. The understandable problem is, it's very hard for people to get out of the lead acid mind set and look at lifepo4 from a very different perspective and the only way you can do that is be experimentation and real hands on use with big and small systems. We've spent many years working with these and it was only a couple of years ago we made the break from lead acid mentality to lifepo4, the results have been great and now we don't even need a cumbersome BMS. We use simple raspberry Pi's running linux to control our pack enclosure temperatures and to control outputs from individual banks in the pack, which again improve the performance of the system. In fact everything in our business runs on linux, which is 21st century technology and we get the same thing from those trapped in last century junk windows and apple. But they can't do what we can and like all fools, run our computer ans off grid systems down. Now we are getting solar and battery retailers inquiring about our systems and chargers. We don't even advertise, nor have a website, all our work comes from customer referral which is all the acceptance we need.

Of course those programmed in the past century approach are extremely reluctant to change, our engineers had great trouble accepting my idea's for this and everyone I spoke to with qualifications said it wouldn't work. Once our engineers put a test one together and tried it for a few days, they changed their minds and now are refining and making it better by developing it so it charges individual cells.

I'm lucky, not trapped in last century technology programming. so didn't find it hard to look at the situation and work out we needed something that just charged bulk inputs and stopped when it reached a set point. Then started bulk recharging at a point where it was not cycling.

Lifpeo4 handles it easily, everyone with real knowledge agrees they can take big charges and don't like floating or other last century settings and we have proved that in our own workshop and the field. So we have not invented anything, just put together all the facts to make something that suits the situation. With just a small amount of research throughout the industry, you will find we have done what the technology needs, according to all the information and nothing special.

[Sunking]

Sunking, I think you owe Dax an apology, as usual you have not read what he has written. My interpretation of what he has written is he does not float charge his batteries, he charges them to 14 volts, shuts off the charge and starts a new charge cycle up to 14 volts when the battery voltage drops to 13.6 volts. I suppose you could loosely call it PWM charging.

Like usual you cannot read and DAX owes me a great deal of money for educating him. He has no clue what FLOAT, BULK, ABSORB, EQ REFRESH or any terms mean. He has no understanding all modes are CC/CV or even what CC/CV is, He cannot understand math by his own admission. If he understood the math, he would know how wrong he is, and would know he is using a 2-Stage Charger. Again he charges up to 14 volts, then lowers the voltage to 13.6 volts and holds which means he is Floating the battery.Rest of us know that is just a 2-Stage Charger. Dax is confused by Marketers Peddling 1-Stage Chargers of low Current calling them Float Charger, Maintainers, Tenders, and a half dozen other names. What he does not understand is all of them are CC/CV chargers. They all do the exact same thing supply a regulated current at a specific voltage. A 12 volt 10 amp charger will charge a 12 volt Pb battery the exact same way it does any Lithium Ion battery.

Lastly a definition of Float or Floating a battery. Not to be confused with a Marketing term called Float Charger as it apparently has confused at least one person in the world.

FLOAT is the Voltage at which a battery is maintained after being charged to hold or maintain its capacity. The battery is neither being charged or discharged and is considered FLOATING or fully Saturated. Just for you Dax FLOAT means the battery is neither charging or discharging, just FLOATING because there is no current to Flow on.

In other words Dax it is virtually turned off. In reality it is not turned off, both the battery and charger at at the same exact voltage. This is where your mind short circuits and cannot do the math to figure it out. For current to flow, there has to be a potential difference in voltage difference. It is called Ohm's Law. a series of 12 math formulas you cannot comprehend. Put another way energy is transferred from a higher order source to a lower order source. In Laymen Terms one voltage must be higher than the other voltage in order for current to flow between them. Here is the math (Ohm's Law) you lack: 0 Volts / X resistance = 0 Amps. Somehow in 3rd grade you did not believeor understand 0 divided by any number = 0. If the battery voltage and charger voltage are equal, no current flows and the VOLTAGE FLOATS because there is no current flowing. To bad you cannot understand such simple math and terms. You would have saved yourself all this embarrassment.

Now for whatever reason those that are knowledgeable will confirm the Definition of Float is exactly what I defined it as, a Voltage Set Point of a CC/CV battery charger. Only DAX says that is not true. Claims that it is ancient history and laws of physics do not apply anymore.


Here is the deal Dax, so listen up and learn something All chargers are CC/CV chargers. They are sold as single to multi-stage chargers. As a Single Mode or just one Voltage Set Point can be marketed as a Float, Bulk, Equalizing, Absorb, Tender, Maintainer, and for even more profit a Lithium battery charger for fools who do not know lithium is the easiest to charge using a 1 stage or Float Charger. Does not matter what it is called, it is a CC/CV mode charger.

Want Multi-Stage Dax. Let;s say two modes. What do you want to call it? Call it anything you want, it is still a CC/CV charger. All 2-stages means is there are now 2 Voltage Set Points. Marketers call the two set points Bulk/Absorb and Float. The 1st Stage is set to a higher voltage for the Bulk of the charge. When the charger senses the current begins to taper off, then lowers the voltage for the batteries to FLOAT at. Dax that is exactly what you are doing. You are using a 2-Stage charger. You charge at 14 volts until one cell reaches 3.5 volts, then lower it to 13.6 volts to Saturate and hold capacity. That is a FLOATING the battery. Exact same thing you do for lead acid, but for different reasons.

[SunEagle]

Don't work for any manufacturer, I own the building company and we make them ourselves, as no one else does. It's the same with the other here who stole our system, but they get theirs made in china and are converted lead acid chargers, so are inadequate ad we are beginning to sell them to other installers now. Certainly never expect anyone to believe what I say, the charge regimes we use are logical, lifepo4 likes bulk charge and nothing else, so that's how we designed them.

Started out with BMS built by someone in Canada which was designed for lifepo4, used those for a couple of years and as we did our research, then convinced my engineers all we had to do was make a charger that did what a lifepoi4 cell wanted, bulk charge till full and shut off.

The next step was to work out recharging and avoid cycling as much as possible, after lots of research and experimentation, came to the conclusion restart charging was best when the pack dropped to 13.6v with bulk charge. Which is still highly charged and according to the experts we deal with, means the pack is not cycling, nor is it floating. Nothing technical about that, just pure common sense and in line with the requirements of the lifepo4 technology.

You can't use our chargers with li-ion, nor any other lithium chemistry as we've tried and li-ion gets very hot and either explodes or ignites when you bulk charge them over 14+v, which they need to be fully charged. So float charging a li-ion cell, makes sense otherwise it will hurt you and your pocket, on the other hand it will lessen the lifespan of the cell. It's the same with controlling the temp of your lifepo4 enclosure, keep them at a constant air temp and they will perform much better and balance really easily. Not rocket science, just plan simple logic.

I think understand it a little better. Thanks for the explanation.

All I ask in return is that while you and some others may have found a better mouse trap to charging lifepo4 batteries the technology is still not widely known and may come under the microscope of doubt.

Understanding that logic is also not rocket science.

People that have technical experience are not easily swayed by advertising glitz and false promises. We need hard facts that help us understand what is being presented as being truthful. Until your technology becomes more mainstream and available you might have an uphill road convincing people to believe in it or even harder to purchase it.

[karrak]

Hows does DAX charge a LFP battery?

He sets his charger Bulk/Absorb to (CC/CV mode)14.0 volts. When the charger voltage reaches 14.4 volts it lowers the voltage to 13.6 vols in a CC/CV mode with a name called Float Charge. Your battery will discharge down to 13.6 volts at which point the charger will supply all power and hold the batteries at 13.6 volts until the charger is turned off or the sun goes down.

Sunking, I think you owe Dax an apology, as usual you have not read what he has written. My interpretation of what he has written is he does not float charge his batteries, he charges them to 14 volts, shuts off the charge and starts a new charge cycle up to 14 volts when the battery voltage drops to 13.6 volts. I suppose you could loosely call it PWM charging.

As for all the stuff about CC/CV charging and all the other rubbish about charging methodologies it is not really relevant to charging from solar. There is no such thing as Constant Current or for that matter under some conditions Constant Voltage charging when charging from solar. You only have Constant Current if the amount of solar energy and the temperature of the solar panels don't alter and Constant Voltage if the solar panels can supply enough power to keep the voltage constant.

One huge advantage of LFP batteries over PB batteries is that you can charge them with any variable charge rate (up to C/2 for large prismatics if you want long life) as long as you keep the charge voltage below 3.45 V/cell.

Dax has already said he is not an engineer so I think it is only courteous that you make allowances for any mistakes in terminology that he might make. I have found the information he has provided very interesting. It just backs up my decision to risk using LFP batteries for both mine and my friends off-grid system and makes me more confident that my understanding of LFP batteries is correct.
Simon

[karrak]

You always know when Sunking is wrong and is in the process of making a bigger fool of himself. He starts abusing and bullying other posters.

If we look back at the original issues in this tread from what I can see Createthis has tried to follow Sunking's advice on how to set up his LFP battery and run into several problems because information that Sunking is supplying is inconsistent and/or incorrect.

Sunking keeps stating that a float voltage of 3.4V/cell (13.6 volts for a 12V battery) equates to around 90%SOC. Both Createthis, myself and others have found that this is not true. The true figure is around 99%SOC.

He also keeps stating that charging LFP batteries to more 90%SOC will halve their lifespan without giving any explanation as to why this is the case.

If you bottom balance an LFP battery you have to make sure the battery is not fully charged as this will result in the weakest cell being driven above its maximum operating voltage. Sunking has suggested that charging a battery to around 90%SOC will give a safe margin to stop this happening. The big problem is that it is not practical to do this when charging from solar. The difference between 98%SOC and approximately 80%SOC is a difference in voltage of 0.04V/cell (0.16 volts for a 12 volt battery). There is no way you will be able to charge an LFP battery to around 90%SOC with any accuracy using solar, I have tried.

His whole LFP charging strategy is based on a number of wrong assumptions and will not work. When people highlight problems with his approach he attacks them and tries to make out that they are incompetent, and/or blames the problems on poor product quality and/or inconsistencies between manufacturers.
Simon

[jflorey2]

Not at all, there is huge difference between the charging and use of energy in an EV compared to off grid.

Right, there is a difference. Nevertheless, what we have learned from one application can (and has been) ported to the other.

An EV doesn't charge whilst being used, off grid does, which makes huge difference in charge regimes.

Incorrect. Straight EV's do indeed charge during regen braking - which happens often. Additionally, PHEV's charge and discharge constantly.

In a solar power system, there is a moderate and steady charge from solar, with a varying discharge rate from appliances - from refrigerators and A/C compressors cycling to lights going on and off. In a PHEV, there is a moderate and steady charge from the IC engine, with a varying discharge from the traction system. That does NOT mean the applications are identical; for example, an EV has a much wider operating (and storage) temperature range, EV's are more sensitive to weight and are stored near full charge more often.

they balance lifepo4 at 3.2v after assembly which is not bottom balancing, other lithium chemistries have different balance points. You can bottom balance an EV, when it is not in use. But you can't bottom balance an off gird system because it is always in use.

You keep saying this and it is strange. Before you commission a new system, it is not in use. That is when bottom balancing is done. You can do it at the battery factory, or you can do it when you first install the batteries. So it can certainly be done, and in fact is done.

An EV will us the majority of its energy before recharging

Most EV's do not use most of their energy before recharging. Average discharge depth for a Tesla 85kwhr battery pack, for example, was measured at 11% over a sample of about 15,000 vehicles last year.

[Sunking]

Then you reject the explanation I put forward regarding floating a battery, when all any one with common sense would do, is look it up and find what i posted, is what is on the net everywhere from battery manufacturers. Floating a battery means maintaining it at full and nothing else, do that with lifepo4 and you stuff them.

Our charge controllers are dedicate for lifepo4, they don't operate like a lead acid charger in any way. Until you can step out of the dim past, you will never understand how this technology works,

Thank you so much for this. It really shows you have no understanding of what you reading, and even worse clearly demonstrates you lack basic fundamental understanding of electric power with respect to batteries. Get this through your thick head there is only 1 way to charge a Lead acid battery and Lithium using a CC/CV algorithm. If you did understand, you would know Bulk/Absord, Float, and Equalize as the exact same CC/CV algorithm.

Again for Lead Acid you first charge to a higher voltage set point of 14.4 volts, then lower Voltage to 13.6 volts to hold capacity and allow for the charger to run loads from the panels so the batteries do not have to.

What are you doing? You first charge to a higher voltage set point of 14.0 volts, then lower Voltage to 13.6 volts to hold capacity and allow for the charger to run loads from the panels so the batteries do not have to.

So please explain what is different other than the initial charge is a bit lower at 14 volts. If it were a commercial Lithium Charger like this one would charge to 14.4 for Top Balance at 100% SOC, then Floats at 13.6 to hold the batteries and run loads from the charge source (panels). How about that, if you want to fully charge LFP you charge to 14.4 volts just like would lead, and then switch 13.6 volts and Float. Exactly the same.

The funny part is you do not know both are the same and has a fancy Marketing Name called a 2-Stage Charger. The joke is on you, and you do not understand why. What you do not understand are Marketed in X number of STAGES.

Some are very simple Single Stage chargers and operates in CC/CV mode with user set voltage of say 14.4 volts. We would market this as Lithium Ion Battery Charger because it Floats at 14.4 volts which is required for a BMS to charge to 100%. We can charge a fortune calling it a specialized Lithium Ion Charger. Fact is it is a CC/CV charger. Take the same Product, lower it to 13.6 volts for lead acid batteries, and call it a Float Charger. Both are the exact same chargers, as they both are CC/CV charger.

Want 2 stages, what about 4 stages smart charger. Every stage is the exact same CC/CV charger. The only thing that changes from one stage to the next is the voltage. They give the STAGES unique names like Bulk/Absorb, Float, and Equalize for example of a 3-STAGE charger. You do not understand the voltage set point is the only thing different between STAGES. You do not understand you are using a 2-STAGE charger and charging exactly like you would a lead acid battery. Charge to a higher voltage initially, then reduce voltage and hold.

[dax]

I know this thread has gone on for a while and there have been other threads concerning Lifepo4 batteries.

I must be getting old because I do not remember what manufacturer you work for that makes the lifepo4 battery chargers.

It might help some of us ancient FLA types better understand the newer technology that you talk about so we can do some of our own research then to just believe everything you say.

Don't work for any manufacturer, I own the building company and we make them ourselves, as no one else does. It's the same with the other here who stole our system, but they get theirs made in china and are converted lead acid chargers, so are inadequate ad we are beginning to sell them to other installers now. Certainly never expect anyone to believe what I say, the charge regimes we use are logical, lifepo4 likes bulk charge and nothing else, so that's how we designed them.

Started out with BMS built by someone in Canada which was designed for lifepo4, used those for a couple of years and as we did our research, then convinced my engineers all we had to do was make a charger that did what a lifepoi4 cell wanted, bulk charge till full and shut off.

The next step was to work out recharging and avoid cycling as much as possible, after lots of research and experimentation, came to the conclusion restart charging was best when the pack dropped to 13.6v with bulk charge. Which is still highly charged and according to the experts we deal with, means the pack is not cycling, nor is it floating. Nothing technical about that, just pure common sense and in line with the requirements of the lifepo4 technology.

You can't use our chargers with li-ion, nor any other lithium chemistry as we've tried and li-ion gets very hot and either explodes or ignites when you bulk charge them over 14+v, which they need to be fully charged. So float charging a li-ion cell, makes sense otherwise it will hurt you and your pocket, on the other hand it will lessen the lifespan of the cell. It's the same with controlling the temp of your lifepo4 enclosure, keep them at a constant air temp and they will perform much better and balance really easily. Not rocket science, just plan simple logic.

[dax]

Dan, Dax,
get it out of your systems.

The moderators dilemma. Incorrect data must be corrected, deleted, or refuted. Moderators can do it, or allow other members to do it for us.
Being a lazy moderator, and spending time tending my batteries and system, I don't have time to correct math errors or bad information, I let other users do it, And their styles vary. They may be "rough". We don't promise a place without "trigger words". get over it,

Sunking, name calling has to stop. Take the user name out of the quote, if you are going to say You Silly Donkey.
half our moderator reports are from thin-skinned folks that were coddled and got a trophy in each class in grade school. They will never get it,

Yes it does seem abuse is the common ground for dealing with each other in the USA, so not surprised. Maybe they aren't "thin skinned folk" at all, just sensible thinking humans who like to discuss without being shot at.

[SunEagle]

I see your problem now, you're stuck back in the last century, constantly referring to lead acid parameters and basing your argument on that primitive understanding. You also show where you stand with your hilariously ignorant claim there are no dedicated lifepo4 solar charge controllers, maybe that's the case in your backward place, but not in our real world. Your paranoid claim of me coming here to start trouble is fanciful in the extreme and really reveals the depth of your deep fear at being wrong, so you use abuse in a futile attempt bully others. I posted here simply because thought others looking for real knowledge, may like to know there are real charge controllers availible and lead acid technology is not lithium technology.

Then you claim all information comes from Ev users, who don't use lifepo4 and everything you reference is li-ion, not lifepo4. All our knowledge with lithium comes from our armed forces, who have been using lifepo4 for close to 10years. You persist on claiming when we shut down charge to the pack, it is floating which is ridiculous. For the last time, the pack is bulk charged until it reaches 14v, then all input is stopped and redirected. When the draw on the pack brings it to 13.6v bulk charging restarts, not float, equalisation or anything else, so the pack receives nothing when charge is off, so it can't be floated.

Then you reject the explanation I put forward regarding floating a battery, when all any one with common sense would do, is look it up and find what i posted, is what is on the net everywhere from battery manufacturers. Floating a battery means maintaining it at full and nothing else, do that with lifepo4 and you stuff them.

Our charge controllers are dedicate for lifepo4, they don't operate like a lead acid charger in any way. Until you can step out of the dim past, you will never understand how this technology works, even if you have all the degrees and lead acid knowledge in the world. We get your approach constantly from the so called experts with heaps of qualifications, when they see our systems in operation, they have nothing more to say. other than it can't work when it does.

I stand by 8 years of hands on experience with lifepo4 installations, with not one dissatisfied customer, compared to the many complaints from off grid people with lead acid chargers. As for balancing, will stick with 7 years of fail proof systems and stick with the recommended balancing regimes of the manufacturer. Our approach has allowed us to get rid of BMS and other useless junk controls, the chargers do the job wonderfully and we are in the middle of testing a lifepo4 dedicated charger that will cut off charge to a cell and redirect it to a lower voltage cells, until all cells reach their limit. This will get rid of the relays and make charging simply.

We also match cells before installation, so each pack and bank has cells with similar capacities, which means charge regimes are so much easier. It's why we set up systems in 500ah charging banks and only use 40-60amp chargers. The same with controlling the temperatures of pack cabinets at specific temps, because it aids the operating and stability of the system.

I know this thread has gone on for a while and there have been other threads concerning Lifepo4 batteries.

I must be getting old because I do not remember what manufacturer you work for that makes the lifepo4 battery chargers.

It might help some of us ancient FLA types better understand the newer technology that you talk about so we can do some of our own research then to just believe everything you say.

[dax]

That is just plain nonsense. You need to stop embarrassing yourself. What if your customers were to seen this? You would be laughed out of biz. DIY

DIY EV owners are quite a bit more educated and knowledgeable about batteries and electrical than Solar professionals. DIY EV owners have quite a bit more money tied up in batteries and give their batteries a lot of TLC. More so than Solar. The large format cells you use were made for EV's 8 years ago. We taught you everything you know, and have forgotten more than you will ever know.

What is different between an EV application and Solar? When it comes down right to it; Operating Temps. With EV's we monitor battery cell temps, not Compensate. We cool than when they get hot, warm them when it gets cold. To protect them we set our cut-off points to more conservative settings. We do not allow them to be fully charged, and we never over discharge them. We give them a lot more care than is practiced for Solar. Know where we got that? From the Commercial EV manufactures. We passed that onto Solar.

Battery Factories charge all Lithium batteries to Storage voltage. For LFP that is 3.2 to 3.3 volts and it has nothing to do with BALANCE. There are only two places you can Balance, either at the Top of Bottom. The only time you can MID BALANCE is if your cell capacities are 1% or less, and only commercial EV manufactures and aerospace can get those kind of matched cells. 3.2 volt sis STORAGE VOLTAGE before shipping. NCO is shipped at 3.5 volts and LiPo is shipped at 3.55 volts.

I see your problem now, you're stuck back in the last century, constantly referring to lead acid parameters and basing your argument on that primitive understanding. You also show where you stand with your hilariously ignorant claim there are no dedicated lifepo4 solar charge controllers, maybe that's the case in your backward place, but not in our real world. Your paranoid claim of me coming here to start trouble is fanciful in the extreme and really reveals the depth of your deep fear at being wrong, so you use abuse in a futile attempt bully others. I posted here simply because thought others looking for real knowledge, may like to know there are real charge controllers availible and lead acid technology is not lithium technology.

Then you claim all information comes from Ev users, who don't use lifepo4 and everything you reference is li-ion, not lifepo4. All our knowledge with lithium comes from our armed forces, who have been using lifepo4 for close to 10years. You persist on claiming when we shut down charge to the pack, it is floating which is ridiculous. For the last time, the pack is bulk charged until it reaches 14v, then all input is stopped and redirected. When the draw on the pack brings it to 13.6v bulk charging restarts, not float, equalisation or anything else, so the pack receives nothing when charge is off, so it can't be floated.

Then you reject the explanation I put forward regarding floating a battery, when all any one with common sense would do, is look it up and find what i posted, is what is on the net everywhere from battery manufacturers. Floating a battery means maintaining it at full and nothing else, do that with lifepo4 and you stuff them.

Our charge controllers are dedicate for lifepo4, they don't operate like a lead acid charger in any way. Until you can step out of the dim past, you will never understand how this technology works, even if you have all the degrees and lead acid knowledge in the world. We get your approach constantly from the so called experts with heaps of qualifications, when they see our systems in operation, they have nothing more to say. other than it can't work when it does.

I stand by 8 years of hands on experience with lifepo4 installations, with not one dissatisfied customer, compared to the many complaints from off grid people with lead acid chargers. As for balancing, will stick with 7 years of fail proof systems and stick with the recommended balancing regimes of the manufacturer. Our approach has allowed us to get rid of BMS and other useless junk controls, the chargers do the job wonderfully and we are in the middle of testing a lifepo4 dedicated charger that will cut off charge to a cell and redirect it to a lower voltage cells, until all cells reach their limit. This will get rid of the relays and make charging simply.

We also match cells before installation, so each pack and bank has cells with similar capacities, which means charge regimes are so much easier. It's why we set up systems in 500ah charging banks and only use 40-60amp chargers. The same with controlling the temperatures of pack cabinets at specific temps, because it aids the operating and stability of the system.

[Mike90250]

Dan, Dax,
get it out of your systems.

The moderators dilemma. Incorrect data must be corrected, deleted, or refuted. Moderators can do it, or allow other members to do it for us.
Being a lazy moderator, and spending time tending my batteries and system, I don't have time to correct math errors or bad information, I let other users do it, And their styles vary. They may be "rough". We don't promise a place without "trigger words". get over it,

Sunking, name calling has to stop. Take the user name out of the quote, if you are going to say You Silly Donkey.
half our moderator reports are from thin-skinned folks that were coddled and got a trophy in each class in grade school. They will never get it,