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Old 25-01-2013, 19:34   #1456
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Re: LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks

One of the give aways that it wasn't the cells themselves is the reports of corrosive "elrectrolyte" seen leaking from the battery area onto the ground. The electrolyte in these batteries is not corrosive, nor is there enough of it to leak out in an amount that could be seen running anywhere.
In regards to solar system sizing to battery capacity, that's the case with AGM batteries and flooded cell as they have a restricted charge acceptance rate, those rules don't apply with lithium ferrous batteries, 3C is about the limit with the Winston and Sinoploy cells, the others maybe be down to 1C but that's still quite high compared to lead acid batteries of any sort.
All the graphs on the Winston and Sinopoly sites are conducted at 0.5C but the stuff in the technical literature that is available gives information regarding curves and Peukert’s effect expected life cycle and extreme testing at much higher rates.
The LYP chemistry is a different to the LFP chemistry in the way it handle temp and high discharge rates.

There is a lot of theory creeping into this thread, theories are great if they are linked to actual tested proved results, otherwise they are just theories.

T1 Terry
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Old 25-01-2013, 19:57   #1457
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Re: LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks

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Originally Posted by hellosailor View Post
FWIW, in the US a 600W solar array for a 400AH battery would not be out of line. The 600W array would provide a full charge for flat batteries in 10 hours, more or less. And since we expect to get the equivalent of 5 hours of full power in any full days use from a solar array, that means a 600W array could recharge a 400AH battery from the 50% discharge point, in one day. Or fully recharge in two days.
Correct, I have 400W of solar for 260Ah of LFPs, which is about the same ratio. At solar's low price per watt these days, extra panels make a lot more dollar sense than an overpriced MPPT controller.

That's my "theory" and I'm sticking to it!
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Old 25-01-2013, 20:29   #1458
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Re: LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks

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Correct, I have 400W of solar for 260Ah of LFPs, which is about the same ratio. At solar's low price per watt these days, extra panels make a lot more dollar sense than an overpriced MPPT controller.

That's my "theory" and I'm sticking to it!
We agree on that part, unless you have a system in excess of 1.5kW an MPPT controller is a waste of good $$, if you have a system that uses more than one charging source at the same time, MPPT wouldn't work, they don't share well with others. It's all has to do with the way they sense battery voltage to determine the correct charging voltage, if they sense a higher voltage as result of another charging source still pumping into the batteries holding them at anything higher than 12.8v they determine the battery to be fully charged, so they go into float mode. The same problem occurs when using lithium batteries, they don't return to bulk chare mode because they never see a voltage less than 12.8v. The only way around it is to raise the charging voltage threshold, not a clever move when it comes to recharging lithium ferrous batteries.

T1 Terry
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Old 25-01-2013, 20:32   #1459
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Re: LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks

Terry does this apply to a MPPT controller built solely to charge LiFePO4 as well?
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Old 25-01-2013, 20:34   #1460
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Re: LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks

My 320 watts of solar with a 200 aH bank fits the above scenarios as well.
My BlueSky MPPT controller is also equipped with the ProSolar monitor/programmer, so I've set it up to go to bulk whenever the battery goes below 13.2 volts.
It returns to float at 13.8 if I remember correctly.
I can't check right now as the boat's in the Port Townsend yard getting a bottom job.
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Old 25-01-2013, 21:00   #1461
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Re: LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks

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Originally Posted by Lagoon4us View Post
Terry does this apply to a MPPT controller built solely to charge LiFePO4 as well?
I've sent you a pm, better than discussing it on an open forum

T1 Terry
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Old 25-01-2013, 23:30   #1462
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Re: LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks

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Originally Posted by T1 Terry View Post
[COLOR=black][FONT=Verdana] if you have a system that uses more than one charging source at the same time, MPPT wouldn't work, they don't share well with others. It's all has to do with the way they sense battery voltage to determine the correct charging voltage, if they sense a higher voltage as result of another charging source still pumping into the batteries holding them at anything higher than 12.8v they determine the battery to be fully charged, so they go into float mode.

MPPT won't make any difference to how well the controller copes with multiple charge sources..

MPPT solar charge controllers have two basic components. The MPPT part and the battery regulating part.
The MPPT part is a voltage conversion that converts the higher panel voltage to the lower battery voltage gaining some current. Think of it as gear box between the panel and battery, keeping the panel operating at efficient "speed".
The second part is the regulator. This reduces the panel output as the battery becomes charged. The regulator part is exactly the same as a non MPPT regulator. Any charging conflict, or problem, will be the same in a MPPT controller as a regular "PWM" (non MPPT ) controller. There are various degrees of sophistication and adjustability in the regulator part of both MPPT and non MPPT controllers.

I don't have a lithium house bank but with a good adjustable solar controller I don't see any problems or conflicts with other charging sources.
The better controllers have an adjustable return voltage and, or, time. This needs to set slightly differently for lithium, but with the right setting I would expect it to function correctly. MPPT, or not, will not change this.

My only slight concern will all solar systems and lithium batteries is voltage hysteresis.
Solar controllers do not have a very tight voltage control on their settings, because with LA there is no need.

So a voltage set point of say 14.2v will see the controller loosely maintain 14.2v, but brief excursions up to as high as 14.5v are seen even with best controllers.
This means the voltage set point for lithium batteries will need to set reasonably low to avoid exceeding the maximium cell voltage, particularly if there is a little cell imbalance.
Given the high charge acceptance of lithium and the desirability of keeping the batteries below 100% for maximium life I don't think it will be a big problem, but I suspect a few expensive batteries may be damaged untill we learn the ideal settings and ways of managing this problem.
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Old 26-01-2013, 01:45   #1463
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Re: LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks

Quote:
Originally Posted by T1 Terry View Post
One of the give aways that it wasn't the cells themselves is the reports of corrosive "elrectrolyte" seen leaking from the battery area onto the ground. The electrolyte in these batteries is not corrosive, nor is there enough of it to leak out in an amount that could be seen running anywhere.
In regards to solar system sizing to battery capacity, that's the case with AGM batteries and flooded cell as they have a restricted charge acceptance rate, those rules don't apply with lithium ferrous batteries, 3C is about the limit with the Winston and Sinoploy cells, the others maybe be down to 1C but that's still quite high compared to lead acid batteries of any sort.
All the graphs on the Winston and Sinopoly sites are conducted at 0.5C but the stuff in the technical literature that is available gives information regarding curves and Peukertís effect expected life cycle and extreme testing at much higher rates.
The LYP chemistry is a different to the LFP chemistry in the way it handle temp and high discharge rates.

There is a lot of theory creeping into this thread, theories are great if they are linked to actual tested proved results, otherwise they are just theories.

T1 Terry
Terry,

Are not, all of the testing and results so far based on high voltage and low amperage..relevancy... over 70 volt(EV Guys), and or single cell 3.45 volt(single) manufacture guys??

Has any one tested as a 12 volt, or 24 volt nominal pack? at the amperage's we typically work at?

From what I can discern, all of the life expectancy and other tests are based on a single prismatic cell(3.xxxV.)

All of the EV guys are working and testing HV, low amp packs (relative) to what a typical house bank that a cruising yacht works at?.

Lloyd

ps: I've read, that all manufactures rate their cells life expectancy, based on a single cell V/amp C/DsC cycle. and no warranty for a pack installed minus a BMS? is that true??

Do you know what the Manufactures warranty includes and excludes???
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Old 26-01-2013, 02:19   #1464
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Re: LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks

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Originally Posted by FlyingCloud1937 View Post
Are not, all of the testing and results so far based on high voltage and low amperage..relevancy... over 70 volt(EV Guys), and or single cell 3.45 volt(single) manufacture guys??

Has any one tested as a 12 volt, or 24 volt nominal pack? at the amperage's we typically work at?

From what I can discern, all of the life expectancy and other tests are based on a single prismatic cell(3.xxxV.)

All of the EV guys are working and testing HV, low amp packs (relative) to what a typical house bank that a cruising yacht works at?
That is completely irrelevant to cell life -- except with regard to balancing. (In the single cell case the potential balancing issue don't exist.) All performance issues, charging issues, chemistry issues, potential failures occur at the level of a cell and the cell doesn't know or care how many other cells are connected in the battery bank. To the extent we know how a 3.2V cell works, we know how a 12.8V or 25.6V bank of 4 or 8 cells work to exactly the same extent, modulo the balancing issues. The higher voltage EV applications are affected by any potential balancing issues far more than a 12.8V or 25.6V house bank.

(I guess you probably already knew that, but you seem to be on a crusade of spreading Fear, Uncertainty, and Doubt about LiFePO4 batteries. I would be pleased to see you apply your formidable talents to a constructive, rather than this destructive, endeavor.)
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Old 26-01-2013, 02:35   #1465
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Re: LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks

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Originally Posted by FlyingCloud1937 View Post
All of the EV guys are working and testing HV, low amp packs (relative) to what a typical house bank that a cruising yacht works at?.
Now you must be joking, right?
EVs, with their range of around 50miles per charge, discharge their packs in about an hour, maybe two. This is 1C to 0.5C discharge current.

References:
Electric cars: the truth about the cost – and range - Telegraph
2013 Chevrolet Volt Boosts EV Range to 38 Miles


Now show me a boat (excluding electric propulsion ones) which does that with a house bank. For reference, that would be continuous load of 200-400 Amperes with 400Ah house bank.

M.

PS: DNFTT
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Old 26-01-2013, 02:37   #1466
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Re: LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks

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That is completely irrelevant to cell life -- except with regard to balancing. (In the single cell case the potential balancing issue don't exist.) All performance issues, charging issues, chemistry issues, potential failures occur at the level of a cell and the cell doesn't know or care how many other cells are connected in the battery bank. To the extent we know how a 3.2V cell works, we know how a 12.8V or 25.6V bank of 4 or 8 cells work to exactly the same extent, modulo the balancing issues. The higher voltage EV applications are affected by any potential balancing issues far more than a 12.8V or 25.6V house bank.

(I guess you probably already knew that, but you seem to be on a crusade of spreading Fear, Uncertainty, and Doubt about LiFePO4 batteries. I would be pleased to see you apply your formidable talents to a constructive, rather than this destructive, endeavor.)
MC,

really give me the math.

Will you warranty my cells... no matter how they are connected.

I'm not talking short circuit.

Heat is amperage!

voltage drop is also amp related.

what say you.

Now for the real thrill, it doesn't matter how many batteries I' sell. I get paid the same.

But if you have a proven technology, that exceeds, today's, then I'll have a line of customer's.

But I can't go there, unless I can put my family in the same boat.

Lloyd
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Old 26-01-2013, 02:45   #1467
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Re: LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks

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Originally Posted by mcarling View Post
That is completely irrelevant to cell life -- except with regard to balancing. (In the single cell case the potential balancing issue don't exist.) All performance issues, charging issues, chemistry issues, potential failures occur at the level of a cell and the cell doesn't know or care how many other cells are connected in the battery bank. To the extent we know how a 3.2V cell works, we know how a 12.8V or 25.6V bank of 4 or 8 cells work to exactly the same extent, modulo the balancing issues. The higher voltage EV applications are affected by any potential balancing issues far more than a 12.8V or 25.6V house bank.

(I guess you probably already knew that, but you seem to be on a crusade of spreading Fear, Uncertainty, and Doubt about LiFePO4 batteries. I would be pleased to see you apply your formidable talents to a constructive, rather than this destructive, endeavor.)
Do you know what the Manufactures warranty includes and excludes???

Please Share,

lloyd
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Old 26-01-2013, 03:01   #1468
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Re: LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks

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Originally Posted by mrm View Post
Now you must be joking, right?
EVs, with their range of around 50miles per charge, discharge their packs in about an hour, maybe two. This is 1C to 0.5C discharge current.

References:
Electric cars: the truth about the cost Ė and range - Telegraph
2013 Chevrolet Volt Boosts EV Range to 38 Miles


Now show me a boat (excluding electric propulsion ones) which does that with a house bank. For reference, that would be continuous load of 200-400 Amperes with 400Ah house bank.

M.

PS: DNFTT
No,

what is an inverter?

How much does it draw?

What is the heat?

just, FSAG's..I would love to see this technology, become real.

Lloyd
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Old 26-01-2013, 03:20   #1469
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Re: LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks

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Originally Posted by FlyingCloud1937 View Post
Do you know what the Manufactures warranty includes and excludes???
I hope you're kidding. First, choose a manufacturer and a product. Then read the warranty.
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Old 26-01-2013, 03:23   #1470
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Re: LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks

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Now for the real thrill, it doesn't matter how many batteries I' sell. I get paid the same.
I take this as an admission that someone is paying you to sell lead-acid batteries by spreading Fear, Uncertainty, and Doubt about LiFePO4 batteries.
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