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

[Sunking]

I think you are talking about the Mains AC supply, the voltage losses have to be controlled here to make sure that all equipment that is plugged into the mains will work properly. Most 12V inverters used in battery based systems will work down to 10.5V, at least a 1.5V or 12.5% drop in voltage.




Only solar design by real dummies would suggest increasing the size of the most expensive component in the system by a factor of 10 to fit in with some overly simplistic design formula. I think that Dax is correct when he says that you are living in the last century, or your design methodology is from the last century. The 1% rule might have had some merit when solar panels were more than ten times the price they are now.

Well this proves you do not understand a thing about simple design guidelines. Only you and Dax would suggest a battery 10 times to large to do the job, not me. I would choose a battery capable of the objective. For starters if Jesse insisted on 12 volt 100 AH LFP and I did say up front use a CALB 12 volt 100 AH battery as it is far supperior with 1/3 the Ri. I know Ri is above your knowledge level but is extremely important to how a battery is going to be have. Not only superior, but less expensive.

For about the same price with performance that exceeds both the CALB and GBS would have been a Concorde 12 volt 150 AH AGM battery which can discharge up to 4C to maintain that 1% SAG. Another would be Odyssey AGM Batteries.

Now I can understand why you Aussies use CHI-COM junk batteries, you cannot good USA made Pb or Li batteries. Your country does not make good batteries, so you have to settle for sloppy seconds. I get it. But you and Dax do not know enough to be answering any questions as you do not understand the basic fundamentals. Neither of you can even understand Ohm's Law. If you did, you would know I am right. We are all laughing....

[Sunking]

Only solar design by real dummies would suggest increasing the size of the most expensive component in the system by a factor of 10 to fit in with some overly simplistic design formula. I think that Dax is correct when he says that you are living in the last century, or your design methodology is from the last century. The 1% rule might have had some merit when solar panels were more than ten times the price they are now.

You already know for fact DAX is an impostor. Even you know what a Floating a battery means. Dax cannot comprehend simple math and cannot understand.

[SunEagle]

Not knowing what you pay per ah for lifepo4 in the USA, can't comment. The majority of our residential customers get their money back within 5 years, based on grid connect costs. Some do better and commercial installations very quickly, the majority are all off grid diesel driven and get their costs back within the first year with the cost of diesel here.

I believe you hit the nail on the head considering the differences between the US and Aus. Most of the power generation is low cost coal or natural gas compared to your high cost diesel fuel. And the consumer price average from the POCO is about $0.10/kWh across the US compared to what I hear much higher in Aus. The reliability is also pretty good here in most of the US except for remote places in the North East like Maine or North West Mountains.

The price per Ah for a lifepo4 battery may be higher here. So with the lower electric costs and the higher Ah costs it makes the payback much longer and much harder to justify here in the US.

[karrak]

Like you said Simon you sell cheap POS CHO-Com junk and are no engineer.

This is your fantasy.

Every loss in any engineered system is accounted for, planned for, and minimized.

Any mininisation of losses have to be done in a cost effective manner.

All electrical codes call for no more than 5% losses from head to toe.

I think you are talking about the Mains AC supply, the voltage losses have to be controlled here to make sure that all equipment that is plugged into the mains will work properly. Most 12V inverters used in battery based systems will work down to 10.5V, at least a 1.5V or 12.5% drop in voltage.

Battery gets a generous 1% of that 5% and even Solar For Dummies call for 1%. Guess you have note read much about what you do.

Using 1% rule on battery voltage sag, your batteries are only good for 20 amps (C/5) or 1/10th what you want.

Only solar design by real dummies would suggest increasing the size of the most expensive component in the system by a factor of 10 to fit in with some overly simplistic design formula. I think that Dax is correct when he says that you are living in the last century, or your design methodology is from the last century. The 1% rule might have had some merit when solar panels were more than ten times the price they are now.

Simon

[dax]

Just because Peltier coolers do not consume much of the day's production (if you count a couple KWh as incidental) does not make them more efficient.

I've seen dozens of destroyed Peltier devices from unequal torque on the mounts and many others fail from poor thermal coupling to the hot & cold sinks.
I actually suspect that many of your Peltier coolers are ineffective after being cycled for 6 months, because it's really hard to perfectly make the environmental sandwich that they need to have a long lifetime, unless you purchase them as a pre-fab assembly from a specialty vendor.
I'd bet a nickel that just a dozen watts of forced air circulation will out perform the Peltier coolers in a LFP battery pack. But we'll never know because you "cant disclose anything".

With respect, you clearly have no idea what you're talking about and it's clear none of you have real experience in lifepo4 off grid. The ridiculous negative claims you all come up with is hilarious, especially when you make them with no working knowledge, just last century lead acid crap. To me it's pathetic elitism at work coming from those desperate to be right, so grasp at non existent straws and sink along with them.

I've revealed just about everything about our system, in plain english. If you can't work out what and how we do it from simple language, then you will never grasp the concept or operational methodology of using lifepo4. no mater what you all claim, they are nothing like lead acid, in charge and usage regimes, reliability and performance. Not prepared to reveal the electronic controls we use, as they are why we keep ahead of the pack and couldn't describe them any way, that's our engineers task. All i do is put forward an idea and they work out if they can get it to work, if so we make a prototype and see how it goes.. Got a few boxes of things that didn't work, have habit of getting ideas constantly, they say it's because I'm a lateral thinker what ever that is.

Do you really think we would use peltiers without proper setups, like heat sinks, fans and controls, if so you really are digging deep into the depths of denial. None of our systems would use a couple of KWH using a peltiers, how about 300-500w at the most and that would be the highest in a desert region. What you don't seem to grasp is, our systems are designed to maintain a certain temperature range, all peltiers do is keep it that way and use very little energy. Thirty seconds either way is enough to maintain the pack at best operating temp for may hours. if you've seen lots of badly setup peltiers, then you are working with those who don't have a clue. Got a peltier cooler in my truck which I built as a experiment to see how they worked and the amount of energy they use, to see if we could use them to control energy packs and that was before we got into lifepo4 and still used lead acid. it's been in use for getting on 10 years and still operates perfectly, even moved it into the new truck because it did such a good job of keeping our food cool whilst we worked and it looks crap.

None of our systems that use peltiers have had any problems, so you can be as negative as you want. We make a lot of money from these system and don't have to advertise at all. Don't worry to much, we get the same from our competitors, but it's the customer that counts and as we've been putting in off grid for almost 40 years. Will back my working knowledge and understanding against any suppose expert. The definition of an expert I like is, "X" is an unknown quantity and spurt is a big drip.

[Sunking]

Is the 1% voltage sag rule from "Sunking's Little Red Rule Book". Which rule number is it? Maybe you could give some technical reasons for it.

Like you said Simon you sell cheap POS CHO-Com junk and are no engineer. It is called Engineering 101 basic way above your head keeping track of numbers, controlling losses. Every loss in any engineered system is accounted for, planned for, and minimized. All electrical codes call for no more than 5% losses from head to toe. Battery gets a generous 1% of that 5% and even Solar For Dummies call for 1%. Guess you have note read much about what you do.

[Sunking]

I left it alone trying to learn stuff until I saw something inaccurate with respect to a subject I may actually know something about. Simply commenting on your prior inaccurate statements with respect to the Carnot cycle and perhaps helping others avoid getting it as wrong as you seem to have it.

No worries JPM. DAX is so far off the mark with Lithium batteries it is funny and making a fool of himself. My God he does not even know what floating a battery is. Even mechanics know what that means.

[Mike90250]

Just because Peltier coolers do not consume much of the day's production (if you count a couple KWh as incidental) does not make them more efficient.

I've seen dozens of destroyed Peltier devices from unequal torque on the mounts and many others fail from poor thermal coupling to the hot & cold sinks.
I actually suspect that many of your Peltier coolers are ineffective after being cycled for 6 months, because it's really hard to perfectly make the environmental sandwich that they need to have a long lifetime, unless you purchase them as a pre-fab assembly from a specialty vendor.
I'd bet a nickel that just a dozen watts of forced air circulation will out perform the Peltier coolers in a LFP battery pack. But we'll never know because you "cant disclose anything".

[dax]

OK. I understand that. We certainly seem to be behind the curve understanding the usage of LiFe batteries.

Hopefully it will become more mainstream here in the US but IMO still has to become a lot cheaper for most people to justify using that type of energy storage.

Not knowing what you pay per ah for lifepo4 in the USA, can't comment. The majority of our residential customers get their money back within 5 years, based on grid connect costs. Some do better and commercial installations very quickly, the majority are all off grid diesel driven and get their costs back within the first year with the cost of diesel here.

[SunEagle]

Sorry, my comments of "years behind",were regarding the use of lifepo4 and not peltiers. For general cooling, peltiers aren't efficient at all, unless you have a constant energy supply and they are even less efficient when compared to inverter technology cooling/freezing, which is what we recommend our customers use in their off grid systems. It's very worthwhile keeping your lifepo4 pack at an even temp, they perform much better especially in the mornings when conditions are cool and charge inputs are high. You only need a 3-5 degree shift in temps for it to have a small effect, which over time reduces life.

OK. I understand that. We certainly seem to be behind the curve understanding the usage of LiFe batteries.

Hopefully it will become more mainstream here in the US but IMO still has to become a lot cheaper for most people to justify using that type of energy storage.

[dax]

Sorry, my comments of "years behind",were regarding the use of lifepo4 and not peltiers. For general cooling, peltiers aren't efficient at all, unless you have a constant energy supply and they are even less efficient when compared to inverter technology cooling/freezing, which is what we recommend our customers use in their off grid systems. It's very worthwhile keeping your lifepo4 pack at an even temp, they perform much better especially in the mornings when conditions are cool and charge inputs are high. You only need a 3-5 degree shift in temps for it to have a small effect, which over time reduces life.

[SunEagle]

The carnot cycle is not efficient, it's really only theoretical and the more I read from the suppose experts here, the more I realise they are clueless when it come to lifepo4. The biggest laugh is they continue to use li-ion as an example of how lifepo4 works and completely misunderstand them, meaning they just babble on making claims which don't represent the reality. Lifepo4 are totally different to li-ion in ever way when dealing with charge discharge.

Unless you have experienced lifepo4 systems where outside 24hr temps ranges from -3 to 35degC in winter and 25-50degC in summer, you're just whistling in the wind. It's also clear they have no idea of how to set up a lifepo4 system, relying again on last century lead acid approaches. If you set up lifepo4 in 500ah banks, using 50ah cells, there is very little increase in cell temps during charging. The only temps you have to worry about are changes to the ambient temperatures and that's when peltiers come in handy and as the majority of their usage would be in the day time, the energy lose is negligible in a decent system. Those in th USA are years behind Aus and probably decades in understanding.

I wouldn't say that the USA is necessarily years behind Aus in understanding peltier technology. It is just so inefficient (about 1/4 compared to conventional compression cooling technology) it isn't considered economical. It might be worth while in Aus to cool batteries but not so much in other places.

[J.P.M.]

Then why are you posting in a lifepo4 thread.

I left it alone trying to learn stuff until I saw something inaccurate with respect to a subject I may actually know something about. Simply commenting on your prior inaccurate statements with respect to the Carnot cycle and perhaps helping others avoid getting it as wrong as you seem to have it.

I try to stay out of areas where I'm ignorant. My comment about my cluelessness was meant as a non volatile attempt at politely suggesting you do the same with respect to Thermodynamics so as to perhaps help avoid spreading misinformation to others as ignorant as, IMO only, you seem to be on the subject of Thermodynamics.

Good luck in your future endeavors.

[dax]

Seems to me that I'm about as clueless about lifepo4 as you are about Thermodynamics. I try to stay out of areas where I'm clueless. Fair enough ?

Then why are you posting in a lifepo4 thread. Don't need to learn about thermodynamics, got 3 engineers for that. Know enough to be able to set up and test in a practical situation and I am not clueless, you are. Our engineers do the sums, make some changes, test under real conditions and not in a lab or home workshop with controlled environments and then we introduce them to our systems. Went through a few engineers until we found those who actually listened and were prepared to step outside their programming into the real world an really experiment.

I understand supposed experts have this deluded belief only their programming is right and things like lateral approaches are wrong. In the real world, lateral approaches actually work and that's what counts. Not some blind claim by over educated clones unable to see past their simple programming and determined to be right against the reality.

Our systems using peltiers works and have had many supposed experts claim otherwise, even after seeing the working data. I put up with this for decades, having experts tell me what and how I build is wrong and won't work. But it does and has made us a lot of money, so to me it means nothing when experts run down our approach and systems. Especially when the experts, are just employed slaves and not real innovators or developers of new approaches. Fair enough.

[J.P.M.]

The carnot cycle is not efficient, it's really only theoretical .

Of course it's theoretical, but to say it's not efficient is off the mark. The Carnot cycle is a way of describing the upper limit of any thermodynamic cycle's efficiency of any device when operating between 2 temperature limits. That (theoretical) Carnot efficiency will vary as the two temp. limits vary.

A Peltier device can be described as a thermodynamic system that operates in a series of consecutive states, sort of in a circular fashion that's called a cycle. It's efficiency can be determined and compared to that of a Carnot cycle device which also operates in a cycle. When that comparison is made, it is found that the Peltier cooling mechanism is usually about 10-15 % as efficient as a device operating on a (theoretical) Carnot cycle. See the open literature if interested or an undergraduate text in Thermodynamics.

Seems to me that I'm about as clueless about lifepo4 as you are about Thermodynamics. I try to stay out of areas where I'm clueless. Fair enough ?