LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks

[rgleason]

Chris Wizgall wrote:
"The SG200 does not have to synchronize from time to time, once it has learned the batteries being monitored. For LiFePo4, our experience is that takes 1-3 cycles to happen. In fact, after this happens, you can disconnect the SG200, say when putting up for the winter, and then reconnect in the spring. The SoC will be reasonably accurate at this point, if allowed to rest (no loads or charging) for a bit when the reconnection happens"

That's great news. Perhaps SOC and other readings including history can become available through the APP bluetooth connection? That would become very useful for triggering changes, etc. however it would require additional CPU and programming which is most appropriately opensource code.

[mat jam]

Originally Posted by newhaul

Mat you have no clue about the use of Lfp as house banks. The data in the video is not really applicable to our low C draw rates nor our low C charge rates .
The video bounces all over the place with the various chemistry of Lipo . And use in ev based systems with high C rates of charge and discharge.

There is a big difference between discharging at a .2C and charging the same as opposed to charging and discharging at 5C as mentioned in the video.

The video does not bounce all over the place. The video is about LifePO4. With these batteries and what they promise, cruisers are using high current drawing appliances /equipment and drawing down their batteries to 20% which according to the expert will reduce life cycles considerably.

Your attempts at obfuscation is duly noted.

[mat jam]

Originally Posted by evm1024

I strongly suggest that you take the time to read every single post in this thread. All of your questions have been talked about at length. Everyone who has engaged you in conversation in this thread has read every post. Reading them is the least you could do in order to come up to speed.

You will find out that many have years of experience with their LiFePO4 banks and that there are some who have years of controlled capacity testing.

I think that reading the 6195 posts would simply be the courteous thing to do.

"If you take your batteries below 50% SoC you can expect hundreds NOT thousands of cycles." Just show me the data that refutes this. Should be easy with all the experience as you say.

[rgleason]

who said this? I believe it is incorrect, look up the manufacturer's charts!

"If you take your batteries below 50% SoC you can expect hundreds NOT thousands of cycles." Just show me the data that refutes this. Should be easy with all the experience as you say.

[newhaul]

Originally Posted by rgleason

who said this? I believe it is incorrect, look up the manufacturer's charts!

"If you take your batteries below 50% SoC you can expect hundreds NOT thousands of cycles." Just show me the data that refutes this. Should be easy with all the experience as you say.

I know for sure mainesail will refute that he routinely runs down to 20% and the last I heard from him on the subject iirc around 5,000 cycles so far on his Winston cells with no loss of capacity.

[newhaul]

Originally Posted by mat jam

The video does not bounce all over the place. The video is about LifePO4. With these batteries and what they promise, cruisers are using high current drawing appliances /equipment and drawing down their batteries to 20% which according to the expert will reduce life cycles considerably.

Your attempts at obfuscation is duly noted.

perhaps you should rewatch the video a few times and read this entire thread your questions have been answered several times .
Or you could ask over on S.A. I'm sure they will tell you the same thing we are nicely trying to tell you .

[CatNewBee]

Originally Posted by mat jam

....The info in the video are pretty accurate for the basis of all LifePO4 batteries. You seem to be skipping over any comments that do not agree with your position. A timeline of 18 months is not a long enough time for you to be singing the praise of these batteries. When you can make the claim in another 6-8 years then you will have my kudos. Otherwise they are just a novelty item with a large price tag that offer SOME benefits. And not cost effective over their use life cycle. MY LA batteries are nearing two years and there is no noticeable degradation. And they have been taken down below 50% numerous times in their first season and left with little charge in the off season until the next season. You see two can play this game. What we want is hard science or evidence, which the video provides, not consumer praise of a product that is in its infancy. You weaken your argument by glazing over major points and focusing on minor ones.

We want the whole truth and nothing but the truth and yes we can handle it.

Did you read my post about the 7 years test of over-charging, abusive float of the LiFeYPO4? Well, not yet 8..9 years, but close.

Dou you have battery powered tools, like a drill or something? Older once have had NiCd or NiMh batteries, the new ones are all LiPo, and sold in Walmart and all other stores. Your cell phone, tablet, notebook, wireless headphones, cameras etc. operate on LiPo or LFP alone, no FLA chemistry there. To say, LFP is not consumer ready is simply ridiculous. Even in automotive e-mobility applications LFP and LiPo lead the pack. All e-bikes, scooter and fancy new e-skateboards, e-boards, e-diving things, drones, e-outboards - all of them are powered by Lithium in consumer professional built applications. Even submarines are LFP powered. Where have you been during the last decade?

I understand, that you are reluctant to invest, this is OK, but do not claim they are not delivering the performance without being able to proof it. There are even consumer grade drop in solutions around for those who do not want to dive in technically and get the most out of it.

[Paul L]

Originally Posted by newhaul

I know for sure mainesail will refute that he routinely runs down to 20% and the last I heard from him on the subject iirc around 5,000 cycles so far on his Winston cells with no loss of capacity.

5,000 cycles is over 13 years daily use. Has this actually been tested by Mainsail?

[Delfin]

Originally Posted by mat jam

Just curious, but what do think makes carbon foam Firefly batteries "dangerous goods"?

Originally Posted by mat jam

I am only paraphrasing what I was told. I imagine their classification - being batteries - is as a dangerous good for shipping.

Ah so. I guess that "major retailer" must not carry batteries at all then, since carbon foam Fireflys are just an AGM battery with a different anode construction than typical. Or, the person you spoke with is clueless, and you, lacking any practical experience, can't detect that.

Originally Posted by mat jam

The info in the video are pretty accurate for the basis of all LifePO4 batteries. You seem to be skipping over any comments that do not agree with your position.

No, just attempting (and failing) to point out to you that while the video is full of great information, it takes a smidgen of knowledge to understand the context. Again, different people have tried to explain this to you to no avail.

Originally Posted by mat jam

A timeline of 18 months is not a long enough time for you to be singing the praise of these batteries.

The only "praises" I am singing are noting empirical observations about voltage, capacity, stability, time to re-charge, etc. My expectation is that cycle life will also be in the thousands, as this chemistry has demonstrated time and again.

Originally Posted by mat jam

When you can make the claim in another 6-8 years then you will have my kudos. Otherwise they are just a novelty item with a large price tag that offer SOME benefits. And not cost effective over their use life cycle.

Could you demonstrate that please? Cost divided by cycles for LFP vs. cost divided by cycles for LA? You might also include costs of recharging via genset for LFP vs. LA since that is how mine are used. Love to see your data, but then again, you don't have any data, do you? Just opinions.

Originally Posted by mat jam

MY LA batteries are nearing two years and there is no noticeable degradation. And they have been taken down below 50% numerous times in their first season and left with little charge in the off season until the next season.

What you just described is the proven method for killing an LA battery, which certainly suggests that you know even less about this topic than I thought you did. So I guess my final bit of advice for you is what has been offered by others. Instead of making a spectacle of yourself arguing a position that no one with any experience would validate, perhaps learn something about the topic, then chime in. A good place to start is the link I sent you many posts ago on MaineSail/CMS/Rod Collins bench testing on LFPs, and given your above comments on how you are torturing your LA bank, perhaps you should brush up a bit on basic chemistry.

Cheers!

[newhaul]

Originally Posted by Paul L

5,000 cycles is over 13 years daily use. Has this actually been tested by Mainsail?

I went back to the discussion last August and I have to correct myself . Rod posted that he had just over 1,000 cycles on his 9 year old Winston cells with a routine 80% dod with no loss of capacity. So my irrc was not correct.

[transmitterdan]

In an industry obsessed with fire risk one wonders how the name Fire Fly made it out of the marketing department. Not to mention the obvious double entendre of not putting them on airplanes especially due to risk of fire. Sheesh....

[senormechanico]

Originally Posted by mat jam

Nobody is claiming LA are are better. Just pointing out the weakness of an argument claiming a proof of longevity with 18 months experience.

There should be objective reasonable verifiable facts presented. I have yet to hear any argument against the main points presented in the video - one being - that if you take your batteries below 50% SoC you can expect hundreds NOT thousands of cycles.

How about at least 5 years use (can't remember the exact purchase date) with discharges as much as 83% a few times? Most daily discharges are taken to 40% (60% remaining).

The 200 aH LiFePo4 bank performs like new.


Has anyone considered that mat jam might just be a troll?

[john61ct]

Originally Posted by newhaul

not hard at all you find the manufacturer and specify what you want

Well the list of cells I'm willing to bother with is: Winston/Thundersky (Voltronix), CALB, GBS, A123 & Sinopoly, with K2 perhaps a contender now that Trojan is working with them?

I do not know of any other high quality makers of LFP, prismatics or cylinders. And have not found any of these to be responsive wrt selling / advising retail consumers of sub-pallet quantities, and believe they do not deal in BMS.

I also want as much as possible to buy my cells through a trustworthy local (North American) supplier for handing warranty issues.

I think you may be referring to Ali or eBay sellers direct from China?

Would be great, but I've seen too many get scammed with no recourse. Some even fraudulently sell as LFP some other LI chemistry, and of course you have no way of knowing the actual provenance of the pouches / cylinders or whatever is inside the packs they are assembing for you.

[john61ct]

Originally Posted by CatNewBee

Regarding the price, LFP is not more expensive than GEL or AGM, in the long run it is cheaper.

Depends on your market. When quality deep cycling lead is available locally for ~$1 / Ah @12V, changes the calculus drastically.

I have not seen quality LFP sources here for under $7-9 / Ah delivered, often much higher.

[newhaul]

Originally Posted by john61ct

Well the list of cells I'm willing to bother with is: Winston/Thundersky (Voltronix), CALB, GBS, A123 & Sinopoly, with K2 perhaps a contender now that Trojan is working with them?

I do not know of any other high quality makers of LFP, prismatics or cylinders. And have not found any of these to be responsive wrt selling / advising retail consumers of sub-pallet quantities, and believe they do not deal in BMS.

I also want as much as possible to buy my cells through a trustworthy local (North American) supplier for handing warranty issues.

I think you may be referring to Ali or eBay sellers direct from China?

Would be great, but I've seen too many get scammed with no recourse. Some even fraudulently sell as LFP some other LI chemistry, and of course you have no way of knowing the actual provenance of the pouches / cylinders or whatever is inside the packs they are assembing for you.

you can get all of those brands direct without the markup that a reseller will add.
However the part of my post you quoted was wrt the bms not the Lfp cells .