LiFePO4 - The future for off-grid battery banks?

[Sunking]

I have not seen you answer this question, but you have posted quite a bit on this thread. Would you mind supplying the information you are asking me to provide?

Have you not figured out yet????

[Sunking]

So apparently my assumptions about how long it takes to charge AGM to 100% against lithium are wrong, so this comes down more to the type of AGM and the chargers capability to provide enough power to a large bank of AGM's?

Wrong again. Battery type has nothing to do charger power. The amount of power is determined by YOU, and only you can answer that question. You have to determine how much power measured in Watt Hours you will use in a day. You have to be able to generate that much in a day to replace it. You do not need to know or care what battery type that is. If you use 1 Kwh of power a day and 3 Sun Hours in winter you had better have have a 500 watt panel, with a 40 amp MPPT controller and a 12 volt 400 AH battery. Makes no fricking difference if it is FLA, AGM, LFP or any alphabet soup battery you want. The only thing that matters is HOW MUCH MONEY will you pay up. The most expensive option you can choose with the shortest life time is AGM and LFP. Some 400% more at end of product life.

It is bad enough to decide to go off-grid and pay 5 times more than the POCO wil charge you using FLA, but do you realy want to pay 20 times more using AGM or LFP? That is the real question you should be asking yourself. Because as of now all your assumptions are false. Any decision based on false assumptions does not end well or work out.

The very first step of any design is to determine the objective. For off-grid solar the objective is HOW MANY WATT HOURS IN A DAY. Until you know that, you have no biz doing anything. The equipment used is just a minor detail and child play.

AGM batteries do have a place in a Solar applications, a very rare specific NICHE application. Such as:

• Unusual installation orientation like on their side.
• Where spills cannot be tolerated like on aircraft.
• Extremely High Charge and/or Discharge currents are required. You thought they could not be high rates when in fact that is what they are made for.
• Extreme Cold below-30 F

[PNjunction]

Why can't the OP get his question answered ??

Because it only turns into a veiled salesmanship job - unintentional or not. Without knowing the exact power needs, and geographical location to determine what the solar insolation is, NO CHEMISTRY is plausible unless you want to wing it.

Lifepo4 is such an upsetting technology, because the "lead acid mindset" can't get over the too-good-to-be-true aspects of it. It also turns wizards into nobodies, because aside from just sizing your bank right and operating it within some common-sense guidelines, you can get on with your life and don't really need to spend a lot of time in forums trying to make the most of it.

It breaks the status-quo, and that deep down is what really upsets people who may have dedicated a lifetime of knowledge to the proper care and feeding of lead acid. All that goes out the window, and are now desperately searching for anything to nitpick on for justification. I know it disturbed me - but that is only after I had actual physical experience.

Offended by the relative ease of operations, the only thing left to do is be a naysayer.

So unless the op wants a sales pitch, which is better served at a professional distributor, I'll ask the question to you:

What system of lifepo4 do YOU have? If none, then why don't you get on the field with us. Cost is minimal for a benchtop. Until then, most of it is just disgruntled naysaying. It's boring after this many years quite frankly.

Mine is a small 12v system, both 20ah and 40ah consisting of GBS cells. (easily scaled into the kw or more range if I really wanted to go there), with NO automatic balancing. Common sense things like you'd use with any chemistry are there, such as an LVD and monitoring. Since I'm running in a "Sub-C" environment like most anyone that uses them for solar storage does, I don't encounter the issues always brought up by other applications, like EV. Although I don't need it, an iCharger 306B was used for initial sanity balance, and to also measure the IR. A West Mountain Radio CBA-IV was used for capacity testing of each cell.

Because I like hydrometers, flukes, and battery maintenance in general (lead-acid included, I LOVE pure-lead agm too!) this may be overkill for some.

The op needs ENGINEERING before salesmanship. That will come when the power needs and solar insolation, or at least a general geographical location can be provided.

Until then, what are YOU using to properly evaluate lifepo4 under real world conditions? Or is it all just talk? Don't be a spectator. Get on the field with us, even with a small benchtop - otherwise what you say is only noise from the stands.

[lkruper]

Most people don't want the criticism and ridicule from the posters that inhabit the site. Potential Advertisers / Sponsors would see it as a net loss to be on here.

Willy, you replied to this poster:
Quote Originally Posted by Iron Bran - Lots of chatter, very few photos. Anyone have actual install photos to share???

I know you must have intended to upload a photo of your LI system, but I don't see it. Could you supply one?

[SunEagle]

The Moderator has spoken, meanwhile back at the ranch I have 8, 260 amp hr LiFepo4 batteries ( $2,500 ) cycling everyday for the last 11 months. I have yet to see the Value in them vs other batteries. I'll let you guess why the other members that have them won't post in here, but I have been labeled as a " Hack " so what do I know.

I want to thank you for providing information concerning a working system. Hopefully anyone interested in building their own system might utilize that information.

By the way, I've been called names much worse but I don't let it bother me.

[Willy T]

The Moderator has spoken, meanwhile back at the ranch I have 8, 260 amp hr LiFepo4 batteries ( $2,500 ) cycling everyday for the last 11 months. I have yet to see the Value in them vs other batteries. I'll let you guess why the other members that have them won't post in here, but I have been labeled as a " Hack " so what do I know.

[lkruper]

Please answer his question. Your post is all well and good, but it is way off the original OP's post that was answered.

I have not seen you answer this question, but you have posted quite a bit on this thread. Would you mind supplying the information you are asking me to provide?

[SunEagle]

Please answer his question. Your post is all well and good, but it is way off the original OP's post that was answered.

Well in the first place the OP "solarnoobie" has not posted since 10-18-2012 so I doubt even providing an answer to his question would matter.

As for the later post from "jedics", his question concerned the lack of a parts list from an "existing working system" that used LiFePO4 batteries.

While I agree having "hands on" "real life" experience concerning technology is a better way to learn and understand what you are dealing with. Sometimes using that technology in a controlled environment (like a lab or test system) does provide useful data that is very accurate.

So asking only those that have first hand "real life" experience with a certain technology to provide data would be limiting all the positive data that might be gotten from other sources.

The original OP is long gone and this thread has more argumentative posts then useful data. So maybe it is time to close it or at least start a new one with up to date hardware data.

[lkruper]

Please answer his question. Your post is all well and good, but it is way off the original OP's post that was answered.

I was not addressing the OP, I was addressing you (and indirectly commenting on his lack of enough information to answer the question).

Did you miss that part

LI is way over my head at the moment, and I am not afraid to admit that. But I am interested in learning and participating in all aspects of battery and solar technology.

[Willy T]

< snip >

Please answer his question. Your post is all well and good, but it is way off the original OP's post that was answered.

Originally Posted by jedics View Post
I noticed there isnt much of people posting what components they are actually using in their system here, is that because moderators dont want the site turning into a sales place?

[lkruper]

It would be fairly obvious that if you don't have a PV Solar System using LiFePo4 batteries, then there should be no opinion since the poster doesn't have a functioning system to give a qualified answer on what components he could use.

Ripping my post apart in Quotes and name calling still doesn't answer his question.

There are many reasons why your opinion regarding the opinion of others is incorrect. Let's start with the opinion of those who purchased a system from an "expert". Any time they have a problem they call the expert. Nothing wrong with that, they paid for it. But do they know anything? They do have a functioning system, don't they? But they have one data point and not necessarily a deep or broad understanding of the subject.

Next take someone who is widely read and has made batteries and solar their hobby and passion. This sort of inquisitive endeavor has no bounds. A person like this can learn more about solar in a few months than a person who has a system learns in their lifetime.


As for whether or not someone can answer the question of the OP, there were not enough specifics given to answer the question even if it was about Flooded Lead Acid batteries. The only thing specific was the "sales" pitch with "I have a friend who works at Tindo Solar" !

Thanks for listening to my opinion

[Willy T]

I dont know,.............maybe people have different opinions, do you know the answer, i dont

It would be fairly obvious that if you don't have a PV Solar System using LiFePo4 batteries, then there should be no opinion since the poster doesn't have a functioning system to give a qualified answer on what components he could use.

Ripping my post apart in Quotes and name calling still doesn't answer his question.

[solar pete]

I agree with you.

Why can't the OP get his question answered ??

I dont know,.............maybe people have different opinions, do you know the answer, i dont

[Willy T]

Howdy, I think PNJ is right this thread feels like it needs to either be deleted or turned into a sticky, ?

I agree with you.

Why can't the OP get his question answered ??

I noticed there isnt much of people posting what components they are actually using in their system here, is that because moderators dont want the site turning into a sales place?

[solar pete]

It's all relative and scalable. That charge has been levied against me elsewhere, from those who have no intention of EVER looking into lifepo4. At least we are on the field, apples-to-apples (one is just bigger than the other!) It is almost as if in the Pb world, that a guy with a flooded battery on a bench top is irrelevant unless he starts out with a 10Kw bank of Rolls-Surrettes as his first project.



True enough, but the worth is far more than mere upfront cost, or weight, even in a fixed installation. It has to do with operational freedom.

No sulfation, so no need to keep or desire them to be fully charged.
PSOC operations are not only totally possible, but from a lifecycle standpoint, encouraged!
Ability to walk away from them in a discharged state and return a year or more later at nearly the same SOC. (no parasitic draws of course)

So IF that operational freedom is important and represents a big break from maintaining a lead-acid based project badly, this could be a major turning point for many.

A bench-top project or Golf-Cart provides the hands-on that is so important, but the biggest thing about it is that unlike mere talk, experience even at the small level, breaks the so-called "lead-acid" operational mentality and prepares you for the bigger stuff should one want to go there.

Put it this way - I'd first trust the guy with a bench top flooded, rather than a guy whose only experience is with AA flashlights merely *talking* about wet-cells.

Anyway, all of this is old news and has been hashed to death since 2008 or so in most forums. I think many are just burned out of repeating the same thing over and over, or more likely, going lifepo4 has turned the corner into being a commodity product. If you want it, it is easy to get these days.

Howdy, I think PNJ is right this thread feels like it needs to either be deleted or turned into a sticky, ?