Lithium Iron Phosphate Batteries; LFP; LiFePO4 discussions

13

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  • RWBRWB Solar Expert Posts: 168 ✭✭✭✭✭
    Re: Lithium Iron Phosphate Batteries; LFP; LiFePO4 discussions
    RCinFLA wrote: »
    Four pack versus 12v AGM, about twice the price ($500-$540 for 100 A-H)

    Its not really fair to compare a AGM battery to a LFP Battery. They are different in so many ways.

    100Ah AGM battery can only provide you 30 amp hours if you want it to last 3000 cycles.

    100Ah LFP Battery can provide you 80 Amp Hours every day for 3000 cycles.


    The 100AGM battery really only gives you 30 Amp Hours every day if your trying to get a long life out of your battery.

    So yea LFP is double the price but it's also more than double the battery.

    LFP - 80 Amp Hours a day x 3000 days gives you = 240,000 Amp Hours
    AGM -30 Amp Hours a day x 3000 days gives you = 90,000 Amp Hours

    The LFP Battery Pack will Provide you with 150,000 More Amp Hours before it starts providing you with 80% of its rated capacity.

    The numbers only get better if you discharge less than 80% DOD everyday.

    70% DOD Daily = 70 AH per day x 5000 Days = 350,000 Amp Hours
    AGM -20 Amp Hours a day x 5000 days gives you = 100,000 Amp Hours

    LFP Gives you 250,000 More Amp Hours than AGM Batteries

    The difference is amazing and its not really fair to compare LFP to AGM, or AGM to LFP.
  • RCinFLARCinFLA Solar Expert Posts: 1,280 ✭✭✭
    Re: Lithium Iron Phosphate Batteries; LFP; LiFePO4 discussions
    RWB wrote: »
    Its not really fair to compare a AGM battery to a LFP Battery. They are different in so many ways.

    The numbers only get better if you discharge less than 80% DOD everyday.

    70% DOD Daily = 70 AH per day x 5000 Days = 350,000 Amp Hours
    AGM -20 Amp Hours a day x 5000 days gives you = 100,000 Amp Hours

    LFP Gives you 250,000 More Amp Hours than AGM Batteries

    The difference is amazing and its not really fair to compare LFP to AGM, or AGM to LFP.

    5000days/365 = 13.7 years! Do you really think they will last that long?

    Accelerated discharge/charge test cycling does not necessarily expose all failure and aging modes. I do agree you can get more usuable A-H per cycle. Longevity remains to be proven.

    I was only comparing price. I am not convinced of a price to payback advantage at their current pricing. One story from the web I came across had 20% of the batteries received failing within a short time. With an unproven track record it is a lot of money to put on the line. If the price ratio was 1.1 to 1.5X I would take the risk.
  • RWBRWB Solar Expert Posts: 168 ✭✭✭✭✭
    Re: Lithium Iron Phosphate Batteries; LFP; LiFePO4 discussions
    RCinFLA wrote: »
    5000days/365 = 13.7 years! Do you really think they will last that long?

    Accelerated discharge/charge test cycling does not necessarily expose all failure and aging modes. I do agree you can get more usuable A-H per cycle. Longevity remains to be proven.

    I was only comparing price. I am not convinced of a price to payback advantage at their current pricing. One story from the web I came across had 20% of the batteries received failing within a short time. With an unproven track record it is a lot of money to put on the line. If the price ratio was 1.1 to 1.5X I would take the risk.

    Yea I think its possible that they could last that long or longer if treated correctly.

    I'm looking for data that proves the manufacturer life cycle ratings wrong too though but have not come up with much on this yet. So until I do find some good data proving the cycle test wrong I'm going to keep my mind open about whats possible.

    For the regular Solar House Setup you can use Lead Acid or LFP, either way will work but for Portable Type Systems the lead acid batteries are not even something we consider because of all the benefits LFP Gives us vs AGM.
  • BB.BB. Super Moderators, Administrators Posts: 30,515 admin
    Re: Gel Batteries
    momofgcm wrote: »
    My batteries are Gel lead acid batteries. My MK batteries are 8G4D LTP. I will have to find out what the LTP stands for.

    Found a nice page here on Terminal Types from Trojan Batteries:

    View Terminal Types - Trojan Battery Company

    LPT (not LTP) stands for Low Profile Terminal

    -Bill :confused:
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • DapdanDapdan Solar Expert Posts: 313 ✭✭
    Re: Lithium Iron Phosphate Batteries; LFP; LiFePO4 discussions

    Hey All,

    I have read this thread with great interest. I have also seen that video where an EV guy complains about a failure rate of 20% and that he cannot get any satisfaction from Thundersky. Here is the link to the video:

    http://www.youtube.com/watch?v=FB1iKYgKSqo

    RWB,

    in your experience have you had any failures or any need to claim on warranty or know of anyone first hand that have attemped a warranty claim. In terms of warranty issues does one have to deal directly with the manufacturer in China or the agent in the US. What does the warranty cover anyway. I am almost sold on this battery tech except that I have seen no details or mentioned on warranty. I dont think is should be an issue since the battery is so " GREAT" the manufacturer should have minimum warranty issues all the more reason to give a "GREAT" warranty.

    Cheers...
    Damani
  • Chuck46Chuck46 Solar Expert Posts: 95
    Re: Lithium Iron Phosphate Batteries; LFP; LiFePO4 discussions

    Alright now so more questions.

    Can you parallel two series strings for more AH?
    If yes what is the maximum recomended number of parallel strings (or is there)?

    The reason for the questions is a 100 AH would not do me for more then a couple of hours as I run a shop, 2300 sq ft home, three wells, heaters for water troughs (keeps em from freezing) and night lights because of predetors.
    Like everyone else I am looking for and answer to battery issues. Lead acid is alright but I know that somewhere there is a bettery mouse trap. So if these batteries can do it maybe the cost is worth it.

    Chuck
  • audredgeraudredger Solar Expert Posts: 272 ✭✭
    Re: Lithium Iron Phosphate Batteries; LFP; LiFePO4 discussions

    Looks to me like the LFYP vs FLA is very competitive an an amp hour basis!

    24 L16RE-B's = 2220 ah @ 24v 555 ah @ 25% DOD = $7390 (NAWS)
    16 400 ah LFYP = 800 ah @ 24v 560 ah @ 70% DOD = $7280 (Includes Shunts $400)

    8-10 years FLA vs 13+ years FLYP; Lighter Weight; No Watering; Little Degradation if left at 50% DOD...

    With only a 3% loss per month this may be a "long" term storage solution!?
    800 ah hours in June would give you 799.82 ah in December

    Beginning to look like a no brainier to me..... only one last question; warranty? If I mess up and kill a FLA there is a pro rated warranty... What if I kill a FLYP? More yard art?
  • mike95490mike95490 Solar Expert Posts: 8,763 ✭✭✭✭✭
    Re: Lithium Iron Phosphate Batteries; LFP; LiFePO4 discussions
    Chuck46 wrote: »
    ...heaters for water troughs

    OUCH!!
    Insulate and passive solar heat in winter ? would that do it?
    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 ,

  • RCinFLARCinFLA Solar Expert Posts: 1,280 ✭✭✭
    Re: Lithium Iron Phosphate Batteries; LFP; LiFePO4 discussions

    From EV guys' experience the warranty is almost not existant. Stated warranty is one year. If you buy from a US distributor you may get the one year warranty. If you buy directly from China, go through the freight clearing process, you likely will get no warranty because you are not big enough for manufacturer to pay attention to. If you are General Motors things are different.

    As to paralleling, the EV guys are doing this. There is a lot of monitoring of cells to keep tabs on conditions. They are drawing 2C and 3C discharges in some cases so are hard on cells. They are putting together >15 kWH battery packs.

    I read that China and a place in East Europe are the two primary world sources of Lithium raw material.

    Probably in a few years, when EV's and hybrids are using large quantity of these batteries, things should get better.
  • Chuck46Chuck46 Solar Expert Posts: 95
    Re: Lithium Iron Phosphate Batteries; LFP; LiFePO4 discussions

    Mike I do wish passive solar would work but it doesnt yet.

    15KV battery pack is impressive so parrellleling is not a problem with these batteries. This might be an answer to my needs.

    Chuck

    Major forgot, I am not sure what is ment by 2C or 3C can yoou give a brief explination?
  • mike95490mike95490 Solar Expert Posts: 8,763 ✭✭✭✭✭
    Re: Lithium Iron Phosphate Batteries; LFP; LiFePO4 discussions
    Chuck46 wrote: »
    Mike I do wish passive solar would work but it doesnt yet.





    Major forgot, I am not sure what is ment by 2C or 3C can yoou give a brief explination?

    2) 2c or 3C C= Capacity A 50 AH Capacity battery 2C = 100Amps 3C = 150A

    1) Let's find a way to make solar heating for the critter tank work. For the same size collector, heat is several times more efficient. If you had just a couple hours of sun a day, a collector, and an intermediate/storage tank, a passive thermosiphon would work. A day without sun, you have to burn generator fuel, only if it gets way below freezing. What about a simple sky cover, that prevents the tank from radiating it's heat out to the stars at night? (thats a way ancients made ice, shallow open trays at night, open to the sky)

    Is much water consumed at night, can it drain into an insulated tank? or a demand waterer fed from an insulated tank. Propane heater ? change out a 30gal propane tank weekly?
    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 ,

  • Chuck46Chuck46 Solar Expert Posts: 95
    Re: Lithium Iron Phosphate Batteries; LFP; LiFePO4 discussions

    http://en.wikipedia.org/wiki/Lithium
    This was interesting reading on lithium.

    Mike, critter tanks are scattered all over the place but the heated ones are for birthing and new borns with their moms. Some of them get real curious about stuff and knock it over or try to eat it so any design has to consider this behavior. I have looked for options but everyone feels their solution is gold plated:roll:
    go figgure.
    Chuck
  • RWBRWB Solar Expert Posts: 168 ✭✭✭✭✭
    Re: Lithium Iron Phosphate Batteries; LFP; LiFePO4 discussions
    Dapdan wrote: »
    Hey All,

    I have read this thread with great interest. I have also seen that video where an EV guy complains about a failure rate of 20% and that he cannot get any satisfaction from Thundersky. Here is the link to the video:

    http://www.youtube.com/watch?v=FB1iKYgKSqo

    RWB,

    in your experience have you had any failures or any need to claim on warranty or know of anyone first hand that have attemped a warranty claim. In terms of warranty issues does one have to deal directly with the manufacturer in China or the agent in the US. What does the warranty cover anyway. I am almost sold on this battery tech except that I have seen no details or mentioned on warranty. I dont think is should be an issue since the battery is so " GREAT" the manufacturer should have minimum warranty issues all the more reason to give a "GREAT" warranty.

    Cheers...
    Damani

    Yes I have had 1 Cell from a 40AH Battery Pack that went bad on me. The Battery pack had been sitting in a hard case by its self for 6 months or so while I forgot about it. I have no idea what the SOC was on the battery before it was thrown into the hard case for 6 months or longer. I do know that when I pulled it out I could see that the Balancing Module was not lit up green like the others so I tested it and it was for sure a dead cell.

    I called my US Supplier and they told me to send it in and they would verify the serial number and that it came from them and then send me a replacement. They honor the 1 year warranty.

    You guys probably do not know this but there is actually a Factory Producing ThunderSky LFP Battery Cells in the USA..................But the cost per cell is double what it cost if they come out of China :)

    And that 1 Cell that went bad is the only cell out of 80 Different Thunder Sky Cells, and I left it sitting for half a year without any protections or knowing the SOC before forgetting about it. I'll get it replaced for free, not big deal.

    Its funny because the Lead Acid Batteries seem to be the batteries that are going bad on us all the time. My partner has thrown away 15 quality Hawker Odyssey AGM Batteries and other brands over the last year because they go bad if you store them for very long, and he charged them once every Month or so but it still did not help.

    I bet there are alot of lead acid batteries out there that never meet their rated output and life cycles.
  • RWBRWB Solar Expert Posts: 168 ✭✭✭✭✭
    Re: Lithium Iron Phosphate Batteries; LFP; LiFePO4 discussions
    RCinFLA wrote: »
    From EV guys' experience the warranty is almost not existant. Stated warranty is one year. If you buy from a US distributor you may get the one year warranty. If you buy directly from China, go through the freight clearing process, you likely will get no warranty because you are not big enough for manufacturer to pay attention to. If you are General Motors things are different.

    As to paralleling, the EV guys are doing this. There is a lot of monitoring of cells to keep tabs on conditions. They are drawing 2C and 3C discharges in some cases so are hard on cells. They are putting together >15 kWH battery packs.

    I read that China and a place in East Europe are the two primary world sources of Lithium raw material.

    Probably in a few years, when EV's and hybrids are using large quantity of these batteries, things should get better.

    Yea there is no need to buy directly from China, Buy from EV Components on one of their Bulk Buys they do every month or 2 months. You can get the cells at 1.10 Dollars per Amp Hour that way, and if you have problems you should have no problem getting it taken care of.

    If you guys have any specific questions call DAVE at EV Components.com he has been selling these batteries for years now, ordering hundreds of thousands of amp hours worth of cells every month. So he knows whats up and can answer your questions what ever they might be.

    Again you can buy from the USA Manufacture of these cells also but will pay more that way. I have no idea who the USA Factory is because I don't want to pay double for the same thing I can get for half the price LOL
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: Lithium Iron Phosphate Batteries; LFP; LiFePO4 discussions

    rwb,
    from you,
    "My partner has thrown away 15 quality Hawker Odyssey AGM Batteries and other brands over the last year because they go bad if you store them for very long, and he charged them once every Month or so but it still did not help."

    forgive my sidestepping here, but somehow this does not sound right as agms do not lose that much of their power during shelving as you are indicating. i have recently, as an experiment, left my sunxtender sit with no loads or float charge for a month just to see the result. the voltage hardly dropped at all and was brought back up in no time. i believe the measured resultant voltage was about 12.7v (exact reading i don't recall) and usually my rest voltage is in the range of 12.8-12.85v. it used to be about .05v higher for the rest voltage, but i'm not going to complain about a battery that is going to be 7 this year. knowing this i suspect there's more to the story as to why your partner is "throwing away" batteries. what of the warranties on those batteries if it's applicable?
  • jeffkrusejeffkruse Solar Expert Posts: 205 ✭✭✭
    Re: Lithium Iron Phosphate Batteries; LFP; LiFePO4 discussions

    I won’t be ready for battery replacement for at least 5 years(I hope) but I do look at these batteries as the next step.

    I have a question, with a Xantrex 4548 and an XW charge controller how many cells would be needed? The XW only goes to 64V for charging. Is the input voltage wide enough for the 4548 to work with these cells. At 64V what would be the SOC?
  • RCinFLARCinFLA Solar Expert Posts: 1,280 ✭✭✭
    Re: Lithium Iron Phosphate Batteries; LFP; LiFePO4 discussions
    jeffkruse wrote: »
    I have a question, with a Xantrex 4548 and an XW charge controller how many cells would be needed? The XW only goes to 64V for charging. Is the input voltage wide enough for the 4548 to work with these cells. At 64V what would be the SOC?

    16 cell in series for 48v system. 3.2vdc nominal per cell X 16 = 51.2 vdc.

    Set bulk at 57.6v, float at 56.0v to 54.5v. I would set low battery cutoff on inverter at 45.0v to 48.0v depending on you max load expectation and A-H ratings of batteries.
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: Lithium Iron Phosphate Batteries; LFP; LiFePO4 discussions

    for those following my comments on the agms going dead, i have moved them into their own thread here,
    http://forum.solar-electric.com/showthread.php?p=52452#post52452
    i did not want to distract from the op as it is a good discussion.
  • audredgeraudredger Solar Expert Posts: 272 ✭✭
    Re: Lithium Iron Phosphate Batteries; LFP; LiFePO4 discussions

    I posted this on the Outback Forum four days ago... no response yet?!

    I am considering a "24v" LiFeYPO4 Battery bank. These battery's typically have a BMS (battery Management System) across each 3.2v cell. This BMS is a 600mA shunt that shunts across the terminals when the cell reaches 3.65v. My question is; with the bulk, absorb & float voltages set at 29v (8x3.65v) how will a my MX60 & FX80 chargers react when a cell tops off and the shunt closes to limit overcharging?

    Perhaps, I can get an understanding here... as I understand it, charge controllers are designed for LA batteries... as they get full the resistance increases, with a LFP and a BMS, as it tops off the shunt will close lowering the resistance (?). Wouldn't the controller misinterpret this and up the amps?
  • GreenerPowerGreenerPower Solar Expert Posts: 264 ✭✭✭✭✭✭
    Re: Lithium Iron Phosphate Batteries; LFP; LiFePO4 discussions

    I feel that 600mA shunt is not sufficient for 10s of Amps charging, especially these cells can be charged at 1C to 3C rate. What happens when, say 9A is still going through the fully charged cell and only 600mA bypassed the cell by the shunt, the voltage across the cell would still jump up beyond the handling capability of the shunt. This site says the 1-year guarantee is honored only if the recommeded BMS is used and those shunts are used on each cell. So are they really effective ? they advertise those are good even for 160AH cell i.e. 160Amps charging ? Maybe that charger and the "1-wire" communication with the shunts is doing somthing else ?

    These BEQs are better but I still fill not sufficient for, say >50A charging while each can shunt 3.65A max.
    GP
  • audredgeraudredger Solar Expert Posts: 272 ✭✭
    Re: Lithium Iron Phosphate Batteries; LFP; LiFePO4 discussions

    the 600mA is a concern for me too... the second BMS looks like it would (may) be short lived what with open circuts...

    I have the potential of putting 108 amps to the bank on a clear day... if I limit the voltage to say 27 volts and only go for 90% SOC, one cell may top off and then those shunts will go off like popcorn! LOL
  • john pjohn p Solar Expert Posts: 814 ✭✭✭
    Re: Lithium Iron Phosphate Batteries; LFP; LiFePO4 discussions

    Greener power what you are missing that a well designed multi stage 50a charger is not going to be putting 50a into the battery pack when the battery pack is almost full.
    At "float " level the charger would just be putting a few amps only into the pack.
    The 600ma really does work and is ok for a battery pack up to about 160ah.
  • audredgeraudredger Solar Expert Posts: 272 ✭✭
    Re: Lithium Iron Phosphate Batteries; LFP; LiFePO4 discussions

    John, its not the float cycle that really concerns me but bulk & absorb... BTW I'm looking at 700ah cells, 400ah min. two banks 24v 700 ah, perhaps 48v bank (s)

    does that "well design charger" also include an 80amp solar charge controller?

    Just asking here.. I don't know.
  • john pjohn p Solar Expert Posts: 814 ✭✭✭
    Re: Lithium Iron Phosphate Batteries; LFP; LiFePO4 discussions

    Any battery charger whether solar or mains powered should be multistage, so that it reduces the charging current to very little as the battery becomes"full"
    I have set up 96v batteries (200ah cells in series)using those 600ma devices and no problems .. they get used by many people on electric vehicles.
    If you are doing parallel banks of batteries , the over/under charge devices only are correcting the cells in its own string.
    I think you worrying about nothing,they do work and have not heard of failures of them in any worrying amounts.
    One thing to make sure you do is never use wire to interconnect cells use only heavy duty bus bars, if necesary look aroung and buy good thick ones. sometimes the ones supplied by some battery suppliers are just too thin. About 3/16 " is about the min to use
  • KamalaKamala Solar Expert Posts: 452 ✭✭
    Re: Lithium Iron Phosphate Batteries; LFP; LiFePO4 discussions

    john p,

    How is that daisy-chained "signal wire" used? I read on the Thudersky site that it interfaces with their BMS which, apparently, is used to control a charger. But do you know how does it? In other words, what kind of information or control signal goes through that daisy chain?

    Kamala
  • audredgeraudredger Solar Expert Posts: 272 ✭✭
    Re: Lithium Iron Phosphate Batteries; LFP; LiFePO4 discussions

    Thank you john.. all good to know

    BTW are there four terminals on the 800ah cells? http://alliancerenewableenergy.com/800-Ah-TS-LFP800AHA.htm
    if so, do they make a special BMS?
  • john pjohn p Solar Expert Posts: 814 ✭✭✭
    Re: Lithium Iron Phosphate Batteries; LFP; LiFePO4 discussions

    Audredger to be 100% honest im not sure but fairly sure they are 2x400ah batts in one case. I do know the extra terminals are not for battery management

    Kamila the signal wire only transmits a voltage signal to a battery management controler. which strictly is not a true battery management controller as all it does is show on a display or LEDs an over or undercharged cell or complete battery , it can then control a relay to turn off the battery charger if fully charged or turn of some device using the battery power if the battery/ies are to far discharged.
    you need the individual cell levellers to ballance the cells.
    600ma ones ok up to 200ahr but you really need 1.5a ones of you using cells from 400ah to 1000 ah

    To further explain about cell charging . you have to think more along the lines the battery charger is only putting out a"big" charge when the battery is "empty" as it approaches "full" the charge is tiny and the first ones to reach "full" just need to drop tiny amounts of charge so the others can catch up.. But the thing to remember is the cell differences when nearly "full" is very small usually something like this best one 3.65 worst one 3.52 or something like that . that is why 600ma is adequate.. and you not going to get"controllers popping like pop corn. I have measured a 48v chain and only found about .12 difference on average between all. dont lose sleep about it but do use ballancing modules if you can redilly get 1.5a ones use them
  • john pjohn p Solar Expert Posts: 814 ✭✭✭
    Re: Lithium Iron Phosphate Batteries; LFP; LiFePO4 discussions

    BELIEVE THIS AND DONT BELIEVE ANYONE ELSE THAT TELLS YOU DIFFERENTnever let a cell drop below 2.2v or it will die .usually the very first time you do it.. YOU HAVE BEEN WARNED
  • audredgeraudredger Solar Expert Posts: 272 ✭✭
    Re: Lithium Iron Phosphate Batteries; LFP; LiFePO4 discussions

    It looked to me like two +'s on one side and two -'s on the other... figured it was to handle the amperage.. may just stick with 400's or 700's
    Thanks
  • john pjohn p Solar Expert Posts: 814 ✭✭✭
    Re: Lithium Iron Phosphate Batteries; LFP; LiFePO4 discussions

    At the moment im working at a place building 3phase 415v inverters for the military and am also doing work with lifpo batteries and another interesting battery that I cant tell you much about but its very good and has 10 yr life and can be cheaply rejuvinated
    We sometimes have "fun" doing destructive testing and all sorts of useless tests because it has to meet some govt specs. that was why the solder test was done,

    sorry cant show any photos as we not allowed cell phones with cameras in the facility.
    IM an electronics tech for almost 45yrs so have trued and seen almost everything. and will always try to give practical advice to anyone, but sometimes I get complained at as my idears dont always fit the accepted"theory model"
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