Lithium Iron Phosphate Batteries; LFP; LiFePO4 discussions

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  • BB.BB. Super Moderators Posts: 26,837 admin
    Re: Gel Batteries

    Basically Lithium is a light weight, energetic metal (put some in water and stand back).

    Lead is very dense and relatively inert (obviously a heavy metal toxin). The dilute sulfuric acid used as an electrolyte is not great stuff to splash around (get some acid in a rag, and you can get spontaneous combustion). But if you treat the battery badly, it is unlikely to do much in the way of excitement (other than if you get sparks near the hydrogen gas during charging/equalization).

    So, the battery guys are trying to make light weight batteries with high energy density and long cycle life for many applications. One of the major problems to date is that many types of Lithium batteries are fairly dangerous if operated outside their normal design range and can have "thermal runaway" (i.e., explosions, fires, etc.). And those fires cannot be put out with water.

    Remember the laptop/cell phone fires with Lithium Ion rechargeable batteries (minor manufacturing errors?). Also, the CR123 non-rechargeable batteries are known to explode if used incorrectly (like one new cell in series with a discharged cell).

    I believe that one of the LFP's major advantages is that the lithium is in a relatively benign form in the cell.

    From the LFP Wiki I linked to earlier:
    Advantages and disadvantages The LiFePO4 battery uses a lithium-ion-derived chemistry and shares many of its advantages and disadvantages with other lithium ion battery chemistries. The key advantages for LiFePO4 when compared with LiCoO2 are improved safety through higher resistance to thermal runaway, longer cycle and calendar life,I][URL="http://en.wikipedia.org/wiki/Wikipedia:Citation_needed"]citation needed[/URL][/I higher current or peak-power rating,[6] and use of iron and phosphate which have lower environmental impact than cobalt. Cost may be a major difference as well, but, that cannot be verified until the cells are more widely used in the marketplace.I][URL="http://en.wikipedia.org/wiki/Wikipedia:Citation_needed"]citation needed[/URL][/I
    LFP batteries have some drawbacks:
    1. The specific energy (energy/volume) of a new LFP battery is somewhat lower than that of a new LiCoO2 battery. Battery manufacturers across the world are currently working to find ways to maximize the energy storage performance and reduce size & weight.[7]
    2. Brand new LFPs have been found to fail prematurely if they are deep cycled (discharged below 33% level) too early. A break-in period of 20 charging cycles is currently recommended by some distributors.I][URL="http://en.wikipedia.org/wiki/Wikipedia:Citation_needed"]citation needed[/URL][/I
    3. Rapid charging will shorten lithium-ion battery (including LFP) life-span when compared to traditional trickle charging.I][URL="http://en.wikipedia.org/wiki/Wikipedia:Citation_needed"]citation needed[/URL][/I
    4. Many brands of LFP's have a low discharge rate compared with lead-acid or LiCoO2. Since discharge rate is a percentage of battery capacity this can be overcome by using a larger battery (more ampère-hours).
    While LiFePO4 cells have lower voltage and energy density than LiCoO2 Li-ion cells, this disadvantage is offset over time by the slower rate of capacity loss (aka greater calendar-life) of LiFePO4 when compared with other lithium-ion battery chemistries (such as LiCoO2 cobalt or LiMn2O4 manganese spinel based lithium-ion polymer batteries or lithium-ion batteries).[8][9] For example:
    • After one year of use, a LiFePO4 cell typically has approximately the same energy density as a LiCoO2 Li-ion cell.
    • Beyond one year of use, a LiFePO4 cell is likely to have higher energy density than a LiCoO2 Li-ion cell due to the differences in their respective calendar-lives.

    Just as a point of interest (at least I found it interesting :roll:)--Powered Copper is used as a fire suppression agent for burning metals:
    • Powdered copper metal (Cu metal) is preferred for fires involving lithium and lithium alloys. Developed in conjunction with the U.S. Navy, it is the only known lithium fire fighting agent which will cling to a vertical surface thus making it the preferred agent on three dimensional and flowing fires.
    • Graphite-based powders are also designed for use on lithium fires. This agent can also be effective on fires involving high-melting metals such as zirconium and titanium.
    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • RWBRWB Solar Expert Posts: 168 ✭✭✭✭✭
    Re: Gel Batteries

    We use these Balancing Modules:

    http://www.evworks.com.au/index.php?product=BMS-CM160-V6

    Read These PDF's

    http://www.evworks.com.au/store/datasheets/EVPower_CM_datasheet.pdf

    http://www.evworks.com.au/store/datasheets/cell_module_installation.pdf


    You can see they start shunting current off at 3.65V so no matter how high you want to charge each cell these modules keep a 4 Cell pack at or below 3.65V x 4 = 14.6V .

    The LFP AC Chargers we use are specifically designed for Thundersky Battery packs and it will bring the battery up to 15V briefly at the end of charging. Not over 15v.

    I have tried regular 14.4V SLA Chargers to charge a Dead LFP Battery and then drained the battery to see how many amp hours I ended up getting out of the battery pack. Then I did the same test with the LFP specific battery charger and tested to see if charging at 15V actually charged the battery any fuller and give me more amp hours vs charging up to 14.4V only. There was only a .25 Amp Hours of difference, no big difference really. Not what you would expect after reading over Thundersky's data.

    I have also found test that the EV guys would do on this exact same thing we are talking about. They found the same thing to be true. You do not gain near as much as what Thundersky says in the charts by raising the charging voltage.

    So my real world testing of never charging over 15V with our LFP AC Charger and 14.6-14.4V Bulk for Solar Charging always charges my batteries up enough to get me well over their rated output, even when I discharge the fully charged battery under a full 1C load.

    So I have no reason to believe that charging at the higher voltages will give you more battery capacity.

    Also if your going to bring your battery voltage up to 16V you will be hearing the alarm on your inverter and probably anything that's connected with a High Voltage Alarm or Disconnect. Usually at 15V things start shutting off or alarming. That's another reason I charge up to 14.6-14.4V Both Work.

    I recently chose 14.4 because it right below where my balancing modules start shunting off the current of the cell to keep the voltage at or below 3.65V. No reason to charge the battery above that voltage because its just going to be shunted off anyways.

    The balancing cells just keep any cell that hits 3.65V first from being over charged. All the cells hit the 3.65V ceiling at the end of bulk charging within a 5min time frame from my testing. Its cool to watch whats going on, and easy to tell if something is wrong with each cell.
  • RWBRWB Solar Expert Posts: 168 ✭✭✭✭✭
    Re: LiFePO4 Battery? Anybody tried them?

    Here is my post from another thread:

    We use these Balancing Modules:

    http://www.evworks.com.au/index.php?...t=BMS-CM160-V6

    Read These PDF's

    http://www.evworks.com.au/store/data..._datasheet.pdf

    http://www.evworks.com.au/store/data...stallation.pdf


    You can see they start shunting current off at 3.65V so no matter how high you want to charge each cell these modules keep a 4 Cell pack at or below 3.65V x 4 = 14.6V .

    The LFP AC Chargers we use are specifically designed for Thundersky Battery packs and it will bring the battery up to 15V briefly at the end of charging. Not over 15v.

    I have tried regular 14.4V SLA Chargers to charge a Dead LFP Battery and then drained the battery to see how many amp hours I ended up getting out of the battery pack. Then I did the same test with the LFP specific battery charger and tested to see if charging at 15V actually charged the battery any fuller and give me more amp hours vs charging up to 14.4V only. There was only a .25 Amp Hours of difference, no big difference really. Not what you would expect after reading over Thundersky's data.

    I have also found test that the EV guys would do on this exact same thing we are talking about. They found the same thing to be true. You do not gain near as much as what Thundersky says in the charts by raising the charging voltage.

    So my real world testing of never charging over 15V with our LFP AC Charger and 14.6-14.4V Bulk for Solar Charging always charges my batteries up enough to get me well over their rated output, even when I discharge the fully charged battery under a full 1C load.

    So I have no reason to believe that charging at the higher voltages will give you more battery capacity.

    Also if your going to bring your battery voltage up to 16V you will be hearing the alarm on your inverter and probably anything that's connected with a High Voltage Alarm or Disconnect. Usually at 15V things start shutting off or alarming. That's another reason I charge up to 14.6-14.4V Both Work.

    I recently chose 14.4 because it right below where my balancing modules start shunting off the current of the cell to keep the voltage at or below 3.65V. No reason to charge the battery above that voltage because its just going to be shunted off anyways.

    The balancing cells just keep any cell that hits 3.65V first from being over charged. All the cells hit the 3.65V ceiling at the end of bulk charging within a 5min time frame from my testing. Its cool to watch whats going on, and easy to tell if something is wrong with each cell.
  • mike95490mike95490 Solar Expert Posts: 7,283 ✭✭✭✭
    Re: Gel Batteries

    So I have my 48V system bunker full of cells and the balancing modules, and my Solar Flooded Lead Acid charger is "charging". How do I convey the "battery full" signals to the charger? They are't really made for remote indication of full, they use internal voltage setpoints. Is it best to reset the factory setpoints to the 58.4V (4 x 14.6v)? Any thermal considerations, I expect the bunker to vary from 35F in the winter, to 75F in the summer, does that change voltage setpoints at all?
    This sounds like a big project to switch over, and I guess I should start planning now, for when current bank expires.
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • RWBRWB Solar Expert Posts: 168 ✭✭✭✭✭
    Re: Gel Batteries

    If it was me I would just wire up my cells to a 48V configuration which is 16 Cells along with a balancing module onto of each cell to balance out each cell from going over 3.65V and becoming over charged, this will also keep all cells at the same voltage on the high end giving you a balanced set of batteries. You will be able to watch each cell as it hits the 3.65V mark and a RED light will show up on the balancing module as seen in the picture.

    Then just do not fully discharge your battery 100% Keep the SOC above 90-80% and do not take the battery voltage below 10V for a 12v bank and you should never have any low voltage cell issues. Low voltage is just as bad for these battery packs as it is the Lead Acid Battery Packs.

    As far as temperature compensation goes you can see that the Thundersky manual does not recommend any special charging changes for -35C weather, it just says that the discharge voltage drops to 1.5v instead of 2.5V.

    You could call some of the Thundersky Resellers and ask them about this like I did and see what they tell you about temp compensation.

    It's not really that complicated, it's just something new that people are not used to yet.
  • mikeomikeo Solar Expert Posts: 385 ✭✭✭
    Re: Gel Batteries
    It's not really that complicated, it's just something new that people are not used to yet.

    Dose the sense wire that links all of the balancing modules just put out a set voltage when all modules are to bypass mode? ON -OFF? Could this be used to shut signal the charger to go to float mode?
  • RWBRWB Solar Expert Posts: 168 ✭✭✭✭✭
    Re: Gel Batteries

    The sense wire just remains a closed circuit unless there is one cell that under 2.5V or above 4.1V then it becomes an open circuit and you lose the current that was running through the wires.

    You can do what ever you want with that signal wire.

    You can buy LFP Specific Battery Chargers also if you want in 12,24, and 48V versions from the same place that sells the balancing modules.

    With my 12V packs once you hit 14.4V with a regular Lead Acid Charger all the cells are pretty much full. You can use a 14.4V Charger without any issues, at least I have without any issues or battery capacity losses.
  • audredgeraudredger Solar Expert Posts: 272 ✭✭✭✭✭✭
    Re: Gel Batteries

    Do LFP batteries degrade like FLA if under charged? In other words, do the sulfate or something similar?

    I'm thinking of my now 4 year old FLA's : 2,610 amps @ 24v that yields only 652 amps @ 24v (25% DOD) vs FLP's 800 amps @ 24v would yield 640 amps @ 24v (80% DOD). What if, I increased the FLP bank capacity to 1400 or 1600; Fully charge in the summer and only partially charged in the winter.... would they degrade with only partial charge for weeks at a time?
  • RWBRWB Solar Expert Posts: 168 ✭✭✭✭✭
    Re: Gel Batteries
    audredger wrote: »
    Do LFP batteries degrade like FLA if under charged? In other words, do the sulfate or something similar?

    I'm thinking of my now 4 year old FLA's : 2,610 amps @ 24v that yields only 652 amps @ 24v (25% DOD) vs FLP's 800 amps @ 24v would yield 640 amps @ 24v (80% DOD). What if, I increased the FLP bank capacity to 1400 or 1600; Fully charge in the summer and only partially charged in the winter.... would they degrade with only partial charge for weeks at a time?

    Good question about what will happen during cold weather.

    Here is a EV Car Thread where they tested these batteries after freezing them

    http://www.diyelectriccar.com/forums/showthread.php/thundersky-200ah-temp-test-39798.html

    Let me know what you guys think.
  • RWBRWB Solar Expert Posts: 168 ✭✭✭✭✭
    Re: Gel Batteries

    We should change the title of this thread.
  • BB.BB. Super Moderators Posts: 26,837 admin
    Re: Lithium Iron Phosphate Batteries; LFP; LiFePO4 discussions

    NOTE:

    I have combined three different Lithium (LFP) Rechargeable Battery Threads into this one.

    If this is a problem, I can split them back apart.

    Please let me know if this does not work for your guys.

    -Bill B. Moderator

    PS: There is still another thread about an LPF Power Pack that one of the members here is building for sale... I have left that thread where it is currently to let everyone discuss that LFP product on its own merits.

    Portable Solar Power

    I have posted this to the end of this LFP thread so that everyone can find it in new posts.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • RCinFLARCinFLA Solar Expert Posts: 1,280 ✭✭✭
    Re: Lithium Iron Phosphate Batteries; LFP; LiFePO4 discussions

    There is probably a lot of real world lessons yet to be learned on these batteries. Looking over the Thundersky data it does seem a bit lacking details. I did not see anything about a break in period where DOD is limited for some number of initial cycles.

    TENERGY has some additional info:
    http://www.all-battery.com/productimages/lifepo4/LiFePO4%20100AH%20battery.pdf

    The charging shunts only can shunt away a maximum of 600 mA (2.2 watts of dissipation). Their primary purpose is to rebalance the cells so any single battery doesn't exceed 4.3 vdc for long period which can be detrimental to cell. The cell volt has an abrupt rise of about 0.1 vdc to 3.65v near end of charge The control line is One Wire protocol and could signal the charger to take action if some cells are not behaving properly. Lithium Iron Phosphate are safer but I would not use them without a charge shunt balancer on each series cell.

    LiIon batteries normally 'die' due more because of Rs increase. The capacity is there you just can't get it out unless current draw is low. The Rs rises versus cycles. Keeping charge and discharge in the 10% to 70% SOC range extends longevity. It would be good to see Thundersky provide this data.

    Cruising the web there are mixed quality messages about these China made batteries. Read some issues with electrode separation from separator resulting in drop in capacity.
  • KamalaKamala Solar Expert Posts: 452
    Re: Lithium Iron Phosphate Batteries; LFP; LiFePO4 discussions

    The LiFePO4 battery is certainly interesting. I have some smaller, portable porjects planned in which I will probably incorporate some of them. The jury is still out regarding their use in large scale, off grid installs, IMHO.

    An excerpt from the doc RC linked to...

    • In case the battery terminals are dirty, clean the terminals with a dry cloth before use. Otherwise performance may occur due to the poor connection with the instrument.

    I like it when "performance occurs!" :roll:

    It's not just a typo. Many more examples of poor translation exist in the linked document. The first time I noticed this phenomena was in 1980 while installing a "booster amp" in my 1979 Monte Carlo. It had a control head with sliding pots for volume and EQ. The instruction manual told me to "slide up and down the volume control." I tried to get on one but they were too small and too close together! :roll:

    Jobs of the future? Learn Mandarin? Probably not. Too archaic. I think there is a more modern Chinese in use today. But I digress...

    K
  • RWBRWB Solar Expert Posts: 168 ✭✭✭✭✭
    Re: Lithium Iron Phosphate Batteries; LFP; LiFePO4 discussions

    Yea the mixed quality issues I have read about also but alot of that is due to the early versions of these cells from quite a few years ago. Even with issues they are still light years better than Lead Acid Batteries from my point of view.

    Thanks BB for combining all this talk to one thread.

    I'm glad we are all talking about this because its only going to raise our knowledge about this somewhat new battery tech that can be so beneficial for Solar Power Systems.

    If we have any specific questions I have some contacts that sell tons of these batteries that I'm sure could get the answers in plain English.
  • audredgeraudredger Solar Expert Posts: 272 ✭✭✭✭✭✭
    Re: LiFePO4 Battery? Anybody tried them?

    I'll try again, do LFP's degrade (sulfate/phosphate) if left in a state of partial discharge?
  • RCinFLARCinFLA Solar Expert Posts: 1,280 ✭✭✭
    Re: Lithium Iron Phosphate Batteries; LFP; LiFePO4 discussions

    Interesting link;

    http://gm-volt.com/2009/03/11/100-fold-lithium-ion-battery-breakthrough/

    Recharge 15kWh in 5 minute! That's only 180 kW feed (not factoring charger efficiency loss). Like to see what the electric plug to auto looks like.

    One substation per gas station.
  • RCinFLARCinFLA Solar Expert Posts: 1,280 ✭✭✭
    Re: LiFePO4 Battery? Anybody tried them?
    audredger wrote: »
    I'll try again, do LFP's degrade (sulfate/phosphate) if left in a state of partial discharge?


    No, actually they degrade more if left at full charge. Best storage is about 50% state of charge. Lower would be better but must avoid over discharge, over time, due to self discharge. 50% SOC is compromise to give max storage time (couple of years).
  • audredgeraudredger Solar Expert Posts: 272 ✭✭✭✭✭✭
    Re: LiFePO4 Battery? Anybody tried them?

    How bad is the self discharge? Better or worse than lead acid?
  • solarvicsolarvic Solar Expert Posts: 1,043 ✭✭✭
    Re: Lithium Iron Phosphate Batteries; LFP; LiFePO4 discussions

    Can you keep these batterys in your house or do you have to keep them in a batterybox outside? Are they a fire hazard? Lots of questions and it is an interesting subject I will follow. S:Dlarvic
  • RCinFLARCinFLA Solar Expert Posts: 1,280 ✭✭✭
    Re: Lithium Iron Phosphate Batteries; LFP; LiFePO4 discussions

    Self discharge is low, like 2% to 3% per month.

    Pretty good at cold temps.

    Fire hazard, relatively safe but can get bad if system lets a cell gets a high charge voltage over 4.5 vdc. Battery would get hot, possibly crack case.

    This is why the 3.65v shunts are put on each cell. This does not completely solve the problem (because shunts can not take full charging current) but does help level charge variance per cell.

    China LiFePO4 battery seems like wild west, a big upcoming thing (primarily automobile market) that every manufacturer that was making toasters last week wants to get into. Quality at this time might be pot luck.
  • RWBRWB Solar Expert Posts: 168 ✭✭✭✭✭
    Re: Lithium Iron Phosphate Batteries; LFP; LiFePO4 discussions

    Here is a whole bunch of info on all the test that these Thunder Sky Cells go through. Its alot of them and they explain how they do it specifically.

    http://www.thunder-sky.com/pdf/test-en.pdf

    Here is the page with the results from a Ohio Lab that put 10 of the 160 AH and 10 of the 400 Amp Hour cells through performance and abuse testing and gave the results. This is a 3rd part lab test results on Thundersky cells

    http://www.thunder-sky.com/technical_en.asp?typeid=116

    They say that the batteries contain zero toxic ingredients.


    From the http://gwl-power.tumblr.com/ website.

    What is the life expectance for the LFP cells?


    The shelf life for LFP cells is at least 10 years. However due to internal discharge (approx 3% a month), the batteries should be charged at least one a year when stored for a long period of time. When taking proper care of the batteries the life span of the cells may be 30 years and more.

    What is the life cycle expectancy of the LFP cells?
    Please see the cycle expectancy diagram. The cycle life is 5000 cycles at 80% capacity level, 8000 cycles at 70% capacity level. (The discharge rate is at 0.5 C.). With performing one full cycle full every day day, the 8000 cycles mean nearly 22 years of use.



    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:
    http://gwl-power.tumblr.com/post/180659 ... o4-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”.
  • RWBRWB Solar Expert Posts: 168 ✭✭✭✭✭
    Re: Lithium Iron Phosphate Batteries; LFP; LiFePO4 discussions

    Also here is a test done on the new 100Amp Hour Thundersky Cell.

    http://endless-sphere.com/forums/download/file.php?id=32315

    What I find interesting that is at the end of the PDF is the 25 Hour Voltage Bleed Test. He charges the Cell up to 4.2V, then lets the battery sit for 25 hours and you see that the cell ends up right at 3.6V stable.

    I thought that was interesting because of our past discussions about charging higher than 14.4 or 14.6V.

    This also verifies what I have been telling you about how the cells almost always give you over their rated capacity in Amp Hours even under 1 c loads. That is what the PDF Shows First.
  • RCinFLARCinFLA Solar Expert Posts: 1,280 ✭✭✭
    Re: Lithium Iron Phosphate Batteries; LFP; LiFePO4 discussions
    RWB wrote: »
    Here is a whole bunch of info on all the test that these Thunder Sky Cells go through. Its alot of them and they explain how they do it specifically.

    http://www.thunder-sky.com/pdf/test-en.pdf
    .

    In Thundersky link, it shows a 'belly strap and side support brace' addition. This was mentioned in a ebay advertisement to prevent anode to separator delamination. It may only occur at high charge/discharge rate but is disturbing.
  • Chuck46Chuck46 Solar Expert Posts: 95
    Re: Lithium Iron Phosphate Batteries; LFP; LiFePO4 discussions

    So let me get this 8 cells for 24 volts a BMS or bypass shunt setup my outback charge controllor and I can have some batteries that last a long time need no water and dont do real wierd stuff in the cold. How much $$$$
  • KamalaKamala Solar Expert Posts: 452
    Re: Lithium Iron Phosphate Batteries; LFP; LiFePO4 discussions

    From ThunderSky...

    For 100AH... $132/ cell. So the answer is... PLENTY!
  • Chuck46Chuck46 Solar Expert Posts: 95
    Re: Lithium Iron Phosphate Batteries; LFP; LiFePO4 discussions

    Yeah I did some more looking and cam up with over $5000. So I guess Ill just read and dream
  • RCinFLARCinFLA Solar Expert Posts: 1,280 ✭✭✭
    Re: Lithium Iron Phosphate Batteries; LFP; LiFePO4 discussions

    Four pack versus 12v AGM, about twice the price ($500-$540 for 100 A-H)
  • RWBRWB Solar Expert Posts: 168 ✭✭✭✭✭
    Re: Lithium Iron Phosphate Batteries; LFP; LiFePO4 discussions
    RCinFLA wrote: »
    In Thundersky link, it shows a 'belly strap and side support brace' addition. This was mentioned in a ebay advertisement to prevent anode to separator delamination. It may only occur at high charge/discharge rate but is disturbing.

    Yea you have to keep in mind that the EV Car Guys that are using these batteries in their cars are discharging at crazy high C rates.

    Most people with Solar Power Systems will not be pulling more than 1C on 200 Amp Hour Battery Packs.
  • KamalaKamala Solar Expert Posts: 452
    Re: Lithium Iron Phosphate Batteries; LFP; LiFePO4 discussions

    Yeah, as I said earlier. Small scale, interesting. Larger scale, to be proven.
  • RWBRWB Solar Expert Posts: 168 ✭✭✭✭✭
    Re: Lithium Iron Phosphate Batteries; LFP; LiFePO4 discussions
    Chuck46 wrote: »
    So let me get this 8 cells for 24 volts a BMS or bypass shunt setup my outback charge controllor and I can have some batteries that last a long time need no water and dont do real wierd stuff in the cold. How much $$$$

    If you want a 24V 200Ah Thundersky Battery Pack you can buy that for $2000 or less. Plus the 8 Balancing Cells for $200.

    So 2200 plus shipping for a 200AH 24V LFP Battery Pack.

    Don't know how you came up with 5 Stacks.
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