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

[deckofficer]

Originally Posted by SailFastTri

Would be interested in what you all think about this product 12V 100Ah,StarkPower 'UltraEnergy" LiFePO Lithium Energy Storage Battery as a "drop in replacement" for LA batteries?

That was bound to happen. Making LiFePO4 a drop in replacement for the large market that doesn't want to do things on the cell level. The pros and cons have been discussed before on this thread. A good way to go with certain limitations for those that want bms and packaging all tidy.

Draw backs are cost per watt, a bit of watering down on some C specs (not as much on this offering than others), and inability to check for yourself cell voltages. For the mass market, this is one of the best LiFePO4 batteries I've seen, but for special apps such as large house banks, I would rather stay with a single series string of an a-hr of my choosing instead of using a bunch of 12 volt batteries in parallel for the needed capacity.

[mrm]

Originally Posted by SailFastTri

Would be interested in what you all think about this product 12V 100Ah,StarkPower 'UltraEnergy" LiFePO Lithium Energy Storage Battery as a "drop in replacement" for LA batteries?

Hmm... not enough capacity for house bank and not enough current for a starting battery. So of not much direct boat use, except in some niche applications (like dedicated SSB supply maybe). Plus, considering that BMS is built in, quite lousy warranty terms.

Here is their mouth:

Originally Posted by product page

LIFETIME:
• Expected number of charge cycles over 2,000.
• Self-discharge rate only 2% per month.
• Expect 8-10 years of battery life that will reduce your operating cost by half
compared to lead acid.

And here is their money:

[quote]
WARRANTY INFORMATION:
1 Year Full Replacement Warranty
[/quote]

Quite a difference.

[deckofficer]

Originally Posted by mrm

Hmm... not enough capacity for house bank and not enough current for a starting battery. So of not much direct boat use, except in some niche applications (like dedicated SSB supply maybe). Plus, considering that BMS is built in, quite lousy warranty terms.

Even though they said 1C discharge in their first table, on the second table they said 20~30C for max discharge. I think they meant pulse, and 10 seconds of cranking a diesel engine would fall under a pulse rating.

[mrm]

Originally Posted by deckofficer

Even though they said 1C discharge in their first table, on the second table they said 20~30C for max discharge. I think they meant pulse, and 10 seconds of cranking a diesel engine would fall under a pulse rating.

Nope.

Their first table is a product specification (Model No. SP-12V100-EP etc..).
Their second table is just some 'starkpower advantages' mumbo-jumbo.

Quite nasty misleading marketing practices IMO.

Also see their note, just above second table:

NOTE:
StarkPower’s “UltraEnergy” are to be used for energy storage applications and NOT for engine starting applications.Max 4 packs in series for 48V systems.Unlimited packs in parallel at 12V.

[ebaugh]

Originally Posted by SailFastTri

Would be interested in what you all think about this product 12V 100Ah,StarkPower 'UltraEnergy" LiFePO Lithium Energy Storage Battery as a "drop in replacement" for LA batteries?

There are several of these companies out there. All are pretty small. I'm certain on 100AH sizing, if you open them up you will find some standard Chinese cells inside. Probably packaged with a small PCB for a BMS of dubious quality. If you go to the dealer/distributer list at Elite Power, the GBS importer and follow the dealer links you will find a couple more of these businesses.

I'm not saying it's a bad idea, but until more is published on the cell management specs and their pricing gets better, you can do more for less buying cells and using a Celllog 8.

Some of these seem to be targeting group 24 and 27 sizes. Unless you are an airplane, or speed racer on land or sea, or maybe a competition car stereo guy it's pretty silly to switch from LA to Li for starting engines with alternator backed charging.

[deckofficer]

A bit of a drift, but they used LiFePO4 400 amp Thunder Sky cells.
Switch1 - YouTube!

The Switch Boat Show Version - YouTube

[Lagoon4us]

A few different charge curves.
http://liionbms.com/pdf/thundersky/TS-LFP100.pdf
http://liionbms.com/pdf/zhejiangheadway/HW38120LS.pdf
http://liionbms.com/pdf/psi/PC40138F1.pdf
http://liionbms.com/pdf/shandong/200...k/GP18EVLF.pdf
http://liionbms.com/pdf/huanyu/HYP-3.2V-100Ah.pdf

[noelex 77]

Originally Posted by ebaugh

Some of these seem to be targeting group 24 and 27 sizes. Unless you are an airplane, or speed racer on land or sea, or maybe a competition car stereo guy it's pretty silly to switch from LA to Li for starting engines with alternator backed charging.

LA batteries are very cheap around capital cities, especially in the USA. In out of the way places the cost goes up dramatically. LA batteries are heavy and are often classified as dangerous goods making transport very expensive.

I am skeptical of the cycle life that is promoted for lithium, nevertheless the price has reached a stage where as an electronic "tinkerer" I am considering lithium.

Within a few years I think we will see this philosophy will extend to more mainstream marine applications.

I suspect the break even point for most cruising boats is now.
The future will see more advantage to lithium as the costs come down and the technology matures.

[Lagoon4us]

Some very interesting test data.
http://www.ev-power.eu/docs/pdf/GWL/...Evaluation.pdf

[Lagoon4us]

An opinion i found regarding YTTRIUM.

The main difference between lifepo4 and lifeypo4 is additional Yttrium at the cathode of the lifeypo4 cells to speed up electron transfer especially at cold temperatures. They are the better choice, especially for electric car usage. I received my cells in spring of last year, my car was one of the first conversions done with Yttrium cells. While driving through the whole last winter here in Germany I´m very surprised of these cells providing high amps at cold, freezing temperatures. I was able to drive my car at the coldest days. Without Yttrium this should not be possible regarding the experience of others. The voltage sag under freezing point is too much with the old cells. Yttriums sag a little bit, but you´re able to drive and receive the whole stored energy. Believe me, they´re really good.

[Lagoon4us]

And this is from the supplier/manufacturer of the cells i've ordered.
FAQ: The difference between the LFP and LFYP
FAQ: Is there a fundamental difference between the LFP (LiFePO4) and LFYP (LiFeYPO4)?

Yes. The essential difference is the use of the chemical element yttrium (Y) instead of iron (Fe).

The chemical structure is in stead of LiFePO4 (LFP) changed to LiFeYPO4 (LFYP). See the chemical composition LiFeYPO4 batteries according to the manufacturer:
lithium & solar power LiFePO4, The material composition of the LiFeYPO4 battery...

The essential difference is in the behavior of chemical elements yttrium and iron. While iron is very susceptible to oxidation and reactions with other chemical compounds, the element yttrium is more chemically stable, not easy to to reach with other compounds. The result is much stronger chemical stability and durability.
While LiFePO4 battery shelf-life is usually given as 3 to 5 years. For batteries using yttrium the service life is set to 10 or more years. Not for nothing did one of the leading scientists said: “Yttrium may be the iron of the future”.

[mbianka]

Originally Posted by deckofficer

Capt Mike,

You were an early adopter of electric propulsion, why not LiFePO4 when your AGMs need replacing? If this thread has proved one thing, that would be you get a lot more bang for the buck, both on purchase and ratings of the cells. My (2) 12 volt packs of 100 a-hr each, if rated like a LA at the 20 hour rate would probably be 160 a-hr, add to that 80% DOD vs 50% DOD, and 2000 cycles vs 500, well you get the picture.

Deckofficer:

Yeah it was a leap of faith to go to Electric Propulsion back in 2008. I did not know anyone who had done it and I could not find any boat the same size as mine to use as an example. It was going to be the best thing I ever did or a very expensive mistake. Even the insurance company said "YOUR GOING TO DO WHAT?" at first. Happily it has worked out better than I expected.

That said I know the LifePO4 technology has a tremendous up side on a boat with electric propulsion. With weight, range, space etc... But, for me my current EP AGM setup has been working so trouble free for the past five years that I don't even think about it much these days. I just drop the hook start the Honda and charge. I'm not ready yet to tempt fate and move to a new battery chemistry. I'm in a "if it ain't broke don't fix it mode". I don't want to spend too much time on my knees manually checking/maintaining battery cells. Did that kind of stuff with the old diesel and the flooded batteries. It's one of the reasons I converted to EP went with AGM. Things are so relatively maintenance free now including with the AGM batteries I would hate to go through the expense of converting and then have additional maintenance with the LifePO4 cells. Still I'm keeping an eye on the technology and might make the switch when it comes time to replace the battery bank. Just want a little more of a track record and looking to see the charging and balancing LifePO4 become as easy as my current setup. I think it's still not there yet. But, think it will be. In the meantime I'm glad you and others are leading the way working out all the kinks and quirks.

[ebaugh]

Originally Posted by mbianka

I think it's still not there yet. But, think it will be. In the meantime I'm glad you and others are leading the way working out all the kinks and quirks.

I suggest you study the EV forums at DIY Electric Car and EVTV.ME to get an appreciation of the differences between AGM/LA and LiFePO4 from an audience with similar applications. I don't know if range is important to you or not, but if so, the differences in EV cars is astounding. It's the difference between going to the market vs a daily commute to the office much further away. You have I think more of a hybrid solution, so it may not all apply. Nevertheless I think it would be interesting. Those guys, the EV community, are the true pioneers of this, not marine house banks.

[T1 Terry]

Originally Posted by Lagoon4us

A few different charge curves.
http://liionbms.com/pdf/thundersky/TS-LFP100.pdf
http://liionbms.com/pdf/zhejiangheadway/HW38120LS.pdf
http://liionbms.com/pdf/psi/PC40138F1.pdf
http://liionbms.com/pdf/shandong/200...k/GP18EVLF.pdf
http://liionbms.com/pdf/huanyu/HYP-3.2V-100Ah.pdf

That first thundersky link is right out of the archives, were did you find it. this is extremely early days stuff, 4.2v charging went out with the aluminium block for the negative terminals. if you check the cell in the last link, 2 aluminium terminal blocks, tells you how far that was into the development stage.
the Headway and wat ever brand the third link is are tipical cylindrical high output low capacity type cells, not suited for storage batteries but quite good for electric bikes etc where light weight but high current is the requirement.
couldn't get the 4th link to load.

T1 Terry

[Lagoon4us]

Originally Posted by T1 Terry

That first thundersky link is right out of the archives, were did you find it. this is extremely early days stuff, 4.2v charging went out with the aluminium block for the negative terminals. if you check the cell in the last link, 2 aluminium terminal blocks, tells you how far that was into the development stage.
the Headway and wat ever brand the third link is are tipical cylindrical high output low capacity type cells, not suited for storage batteries but quite good for electric bikes etc where light weight but high current is the requirement.
couldn't get the 4th link to load.

T1 Terry

And it changes continually...