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

[sytaniwha]

On the "Lithium Battery Failures" posting.

I agree with "downunder" that this particular link is talking about all "Lithium-Ion" cell chemistries in general. LiFePO4 is indeed included in the general "Li-Ion" category because it is a lithium based chemistry, but it does have some important differences to most of the other Li-Ion chemistries.

Firstly, the major difference between the Li-Ion chemistries is in the cathode. The most common kind of Li-Ion cell uses a lithium-cobalt cathode, and is widely used in portable devices (phones, notebooks, etc etc). It is this type of Li-Ion which has undergone some notable "violent dis-assembly" events, resulting in a few fires and harm to some people. A lot of those events came about due to short circuits, and have earned Li-Ion generally a bad name.

LiFePO4 was in part developed because of the inherent thermal and electrical instability of Li-Co based chemistries. Some of the characteristics of LiFePO4 which differentiates it from other Li-Ion chemistries are:

• the bonds between atoms in the cathode are much stronger and so oxygen cannot be released, making them virtually in-combustible (it's the loose inter-atomic bonds which make LiCo dangerous),
• no lithium remains in the cathode of a fully charged cell, vs about 50% for LiCo, which makes the cells very resilient to over-charging from a safety perspective,
• the cells are very temperature stable, vs LiCo becoming unstable above 60 degC,
• it has a lower energy density (15% below LiCo),
• it has greater cycle life capacity stability (i.e. LiCo capacity reduces more quickly with cycles),
• it cannot be charged or discharged at rates as high as LiCo,

I could go on, but hopefully you get the idea: there are some trade-offs which have been made in LiFePO4 in order to make it more stable and as safe as any battery chemistry.

I think one of the critical real-world illustrations of the safety difference between LiFePO4 and other Li-Ion chemistries is in the classification for flying. LiFePO4 can be air-freighted in bulk (e.g. my 4 * 400 Ahr cells were flown China-Hong Kong-Kuala Lumpur-Langkawi), whereas equivalent cells in other lithium chemistries cannot. I am not aware of any jurisdiction in the world where they cannot be flown - but I'm not an expert in that so I'm open to correction on that one.

So, in my opinion, (and having worked in the rechargeable battery industry for many years), LiFePO4 cells are as safe as any other rechargeable chemistry, and definitely safer than wet-cell lead-acid and other Li-Ion tech.

I think that they are perfectly suited to yacht house-bank applications, and by far the best option that we have at the moment.

Cheers,
Paul.

[EmPrep]

First post here and I want to thank all of you for the great information that you have afforded me and my emergency preparedness business in this thread.

My project presently is to long term compare (4) Crown CR-225 225 Ah 6 volts recently purchased with a similarly sized bank of LiFePo4s that I have yet to source for emergency back up power only (I will be using this charger with most likely the custom charge setting if the pre-programmed LiPO setting is not compatible with LiFePO4s Marine Battery Charger - Sterling Power ProCharge Ultra- Power Factor Corrected (PFC) PCU - 60amp
). My thinking behind the purchase of this charger was that it consumes but 900 watts of fluctuating power that is well within the continuous rating of the Honda EU2000i that we already offer and obviously the one programmable charging algorithm for future battery chemistries.

In exchange for the generous information already provided here I certainly promise to keep members abreast of how this long term test progresses yet I really need to know what is the best quality cell (400Ah or so total?) of this type currently available here in the states (I picked the Crown on the FLA side which is most likely debatable).

I understand that there is more equipment needed, protocol to be followed and that I need to reread this thread several more times to understand the results that you would genuinely be interested in...yet I would sincerely appreciate any help given and wish all of you/yours a very Merry Christmas.

John

[Target9000]

So, I was thinking (wishing really) that you more experienced electric types would start posting links, costs, sources, etc for the equipment you're using. Diagrams and photos are fun too.

I started looking online for where to find cells, but the 400ah variety seem pretty scarce and the few sources I found look a little shady. Also, are there other options for the LVC than the vetus battery watch? I looked for it online, very little info.

I know you guys are partial to the cell monitors too. How do they work in conjunction with a traditional battery monitor like the Victron or Xantrex? Also, I'm sure they generate a ton of data, but what someone like myself needs is... A way to draw meaningful conclusions on that data. Are you aggregating the data on a PC and using it in some way? Is there a battery monitor out there that does it for you? etc.

What are you using to protect the batteries from corrosion? What type of studs are you using? Where are they mounted?

Can we get some nitty gritty details going?

[EmPrep]

Originally Posted by Target9000

"So, I was thinking (wishing really) that you more experienced electric types would start posting links, costs, sources, etc for the equipment you're using. Diagrams and photos are fun too.

I started looking online for where to find cells, but the 400ah variety seem pretty scarce and the few sources I found look a little shady..."

This is what I have run in to as well...anything evidently reasonably priced and/or of any quality originating from but one country (buyer beware)...and at least two members on this thread purchasing from another with no brand given or follow up experience in play (more power to all three and no obligation to do so implied).

It's hard to give back to this thread and forum membership if there is (seemingly) no consensus on at least the top two or three manufacturers/models out there, where we can source them and frankly what brands to avoid given where they're coming from, cost overall and other goodies needed to properly/safely consider their use.

Not complaining one bit here and like the poster above me I'm sure...both grateful and hoping that it doesn't come off that way!

[downunder]

From this forum it seems at present the only economocal LiFeO4 batteries are being sourced from China and trials seem very successful and promising.

To imagine other manufactures in other countries such as USA, Europe etc are going to be competetive is I think fanciful. Actually the Chinese manufacturers are the ones doing the development of volume/price necessary to make LiFeo4 accessible to the majority of us crusiers. Nobody else is doing it. Who??????

Based on the work done by these pioneers on boats and earlier by the electric car pioneers I believe we can accept the current quality of LiFeO4 at prices now similar to convential AGM bank prices.

Price will only improve. We can always however pay $20,000+ for a high end product from USA/ Europe(mastervolt) if we chose.

Just Beware. Your choice.

[goboatingnow]

Originally Posted by downunder

From this forum it seems at present the only economocal LiFeO4 batteries are being sourced from China and trials seem very successful and promising.

To imagine other manufactures in other countries such as USA, Europe etc are going to be competetive is I think fanciful. Actually the Chinese manufacturers are the ones doing the development of volume/price necessary to make LiFeo4 accessible to the majority of us crusiers. Nobody else is doing it. Who??????

Based on the work done by these pioneers on boats and earlier by the electric car pioneers I believe we can accept the current quality of LiFeO4 at prices now similar to convential AGM bank prices.

Price will only improve. We can always however pay $20,000+ for a high end product from USA/ Europe(mastervolt) if we chose.

Just Beware. Your choice.

The Chinese sources or their distributors are generally ok. There was obviously th e big issue with EV components last year but that wasn't any thing to do with the manufacturers. I have one of the thunder sky units and I'm looking to buy some of winstons cells. Any one in Europe know a good outlets. Air freights costs are very high from china

Dave

[deckofficer]

I read a news report just today that CALB has started a price war. This US based retailer might be able to, in the not too distant future, be in position to pass those savings to their customers. We can only hope.

CALB/SkyEnergy : Lithium Batteries, Empowering EVs

[EmPrep]

Originally Posted by deckofficer

I read a news report just today that CALB has started a price war. This US based retailer might be able to, in the not too distant future, be in position to pass those savings to their customers. We can only hope.

CALB/SkyEnergy : Lithium Batteries, Empowering EVs

A price war with who?

I look at this company and see all the names that I am familiar with in my research so far (Thundersky, CALB, Sinopoly) and am assuming that Winston now has his own line as well (although I don't know how one tells the difference anymore given that many companies could care less whose technology that they are using given any permission to do so or not).

A price war sounds good...but how many companies (with U.S. distribution) would be involved, what are their names and would each product then offered be of the same quality?

I'm about ready to find out who exactly sells this Winston fella's stuff here in the Midwest, buy one and forget about it!

[EmPrep]

...here's some food for thought from at least one distributor on price cutting (ie. the upcoming price war mentioned above) and overall quality regarding LiFePO4s: LiFePO4 Technology : Lithium Batteries, Empowering EVs
"...However, in order to make a cheaper LiFePO4 battery some companies will use lower grade materials to become more price competitive..."

It seems funny that there has been so much uproar this summer involving this fellow Winston, the large part both he, his much argued about technology and now spilt(?) multi-billion dollar companies have recently went through...but not much at all (that I can find) on how prices will soon come down through (cough) 'competition'...with 'quality' cells somehow being provided by all players moving forward into 2012 and beyond.

Are there any independent forum enthusiasts or electrical engineer DIYers online testing/using these things on a regular basis...and if so...why hasn't a clear winner been chosen (or even a close second) as to what is the best cell out there or what importer here in the states works hardest to make these customers happy at any price point?

Since there seems to be no consensus

[witzgall]

On the link 1000 meter, it calculates, or allows you to set a Charge Efficiency Factor. Essentially, this is how many of the amps generated actually are stored into the battery. It is expressed as a percentage, up to 99%. This would mean that if you generated 100 ah, 99 of them would be stored into the battery.

Does anyone have any wisdom on what this should be set to for LIFEPO4? I am not sure I trust it to calculate this, as it has to reach full charge (as the meter sees it) over an over to tweak this value.


Chris

[CharlieJ]

The CEF is calculated using the Peukert Exponent that is User entered during setup as part of the algorithm. As the Peukert effect is nearly non-existent in LFP batteries, and barring information from the battery manufacturer, I would recommend a Peukert Exponent of 1.05 as a starting point. You will probably find that after a few cycles, the PE can be reduced until you have a match.

Of course, you can go through the entire PE derivation by doing a test discharge and calculation if you are a glutton for punishment!

[s/v Jedi]

Google search shows a Peukert coefficient of 1.05 as typical for LiFePO4.

cheers,
Nick.

[T1 Terry]

Bugga, I one finger typed a big long post and it vanished, must have been a sign :lol:

A sort of an answer to 'what batteries are best and what to avoid'

Up until roughly 12 mths ago in the prismatic cell market (the ones mostly used for house batteries) it was a bit tricky to say who's batteries were better.
The way Chinese 'Sellers' were set up, what they sold didn't reflect any particular manufacturer. Thundersky was yellow, CALB was blue and Hi Power was grey. They supplied their cases to which ever start up factory offered the best price and they put their plates in them. They were all a standard size so this worked well.
Then Winston Chung came on the scene and decided quality needed to be improved to lift the game if they were going to crack the world market.
As the lead man at Thundersky he established better quality control measures in a few of the factories and this lead to a more uniform product. He also carried out research into different chemistries but he did this under his own company name as far as I can tell while still running Thundersky, things are one a little different in China I guess and ethics…… well
So CALB cells became known for their close internal resistance matching within a supplied set but this really only happened from the factory so any overseas reseller is unlikely to have this same service to offer. It's a long and complex procedure to test each cell to group them, it’s not just the cell voltage they leave the factory at. Capacity matching, discharge rate matching etc
Thundersky had a big split up, Winston Chung went out on his own with Winston Battery Ltd and his patented LYP chemistry (yttrium in the mix and a modified electrolyte) and locked a few factories in as his sole manufacturers.
Sinopoly split off and still sell the LFP cells from a few of the other factories and also offer a different configuration cell, lower and wider but still in the same capacity range. I guess they still hold the licence for that technology so CALB would be made under licence to Thundersky/Sinopoly still I presume. No idea who manufactures the hi Power cells. There are a few other start up sellers but not much is known about them.
There is another seller and possibly also the manufacturer in Taiwan, Heter, supposed to have very good test procedures but still trying to break into the market big time.
Winston have developed another chemistry, lithium sulphur, but these are very big capacity batteries at this stage and their cycle life isn’t as good but they are much lighter so the energy density numbers are better.
Now, enter the biggest lithium battery manufacturing plant in the world, Liotech, a Chinese/Russia venture Russia Builds Liotech, World’s Largest Lithium Ion Battery Factory | The Green Optimistic A combination of Thundersky and a government based Russia company. I guess Winston Chung is spitting chips at the moment.

My way of looking at it, stay with the known seller brands, Heter may be worth considering, Tawain have quite a good quality reputation these days.

Keep in mid also, these are built as electric vehicle batteries, as house batteries they don’t work near as hard so comparison testing is only going to reflect EV performance, not house battery performance.

T1 Terry

[OceanPlanet]

I've been using 1.05 or so for the Peukert's setting also.

A quick reminder for those just joining this very long thread...the various brand names mentioned here (Thundersky, CALB, whatever) are simply CELL manufacturers. For a comprehensive house battery system there is quite a way to go from the basic cells to having a reliable and safe house bank system.

Sure, some of the DIY aces here are fully capable of assembling something that can work for them with a minimalist (or no) BMS (Battery Management System). However, no professional marine systems installer worth their salt would want to send their clients out to see without a fully-protected system that their client can't mess up.

All I'm sayin is that there are DIY cells/kits, and then there are fully protected systems that are designed specifically for house banks. Very different things.

[goboatingnow]

Originally Posted by OceanPlanet

I've been using 1.05 or so for the Peukert's setting also.

A quick reminder for those just joining this very long thread...the various brand names mentioned here (Thundersky, CALB, whatever) are simply CELL manufacturers. For a comprehensive house battery system there is quite a way to go from the basic cells to having a reliable and safe house bank system.

Sure, some of the DIY aces here are fully capable of assembling something that can work for them with a minimalist (or no) BMS (Battery Management System). However, no professional marine systems installer worth their salt would want to send their clients out to see without a fully-protected system that their client can't mess up.

All I'm sayin is that there are DIY cells/kits, and then there are fully protected systems that are designed specifically for house banks. Very different things.

This is wrong, an industry has grown up around LifePo4 that's a bit like the one that used to exist for osmosis treatment. It uses fear of unknown technology coupled with application feedback from other uses, especially EV to build a mini-industry that suggests you need all these bells and whistles. Let me say first, fair play to them. The truth is you can use liFepo4 batteries with the same approach as current LAs. ( in typical boat environments) , in fact they are easier to use , likely to survive much longer and provide you with all the benefits of such technology.

You don't need low voltage cutoffs, cell monitors or complicated BMS. While you risk more money then conventional LAs you still don't need these devices. At a very minimum an LVC is useful to have and are readily available as battery watch systems already produced by several marine electronics manufacturers. The rest you can do with a multimeter and even if you don't have a multimeter, it's still difficult to f&€k it up.

As to " However, no professional marine systems installer worth their salt would want to send their clients out to see without a fully-protected system that their client can't mess up." what fantastic irony. God help "the clients" when all this "can,t mess up" stuff fails.

Dave