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LiFePO4 - The future for off-grid battery banks?

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  • #31
    John P,
    thank you once more. I will check once more data concerning solar isolation.

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    • #32
      Hi Josko -

      Try PV Watts http://rredc.nrel.gov/solar/calculat...ttsv1_intl.cgi

      Russ
      [SIGPIC][/SIGPIC]

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      • #33
        Russ, I can not open a link?

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        • #34
          I'll try again - that was the link I used but after your comment I could not open it either!

          http://rredc.nrel.gov/solar/calculat...ATTS/version1/

          Russ
          [SIGPIC][/SIGPIC]

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          • #35
            Originally posted by Jonathan Cole View Post
            Hi Steve,

            LiFePo cells have a higher nominal voltage than lead acid batteries and usually the charge controller is programmed for specific batteries and their optimal charging characteristics. No charge controllers that I know of are set up for these batteries. What make of solar charge controller did you use?

            By the way, an MPPT charge controller only makes economic sense if you live in the high cool lattitudes. Otherwise it is more cost effective to purchase a pulse width modulation charge controller which is less than half the price and has more than twice the warranty (5 years vs. 2 years). You are better off getting the cheaper charge controller and spending the savings on additionall PV panels which have a 20-25 year warranty.

            Jonathan
            Sorry for my delay to this question. I have a Morningstar TS_MPPT60 controller to charge it is set to 'custom' mode where it regulates voltage and current and I turn off all equilization and float settings.

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            • #36
              this is very cool

              Just joined this thread. I am interested in BMS myself. Am looking for a solar setup with around 2kwh+ storage. Will be following this thread.

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              • #37
                Hi plateauhops, Welcome to Solar Panel Talk!

                You can learn along with the rest of us! Most of us have a lot more to learn than Mike & Sunking but everyone should learn something everyday!

                I admit it is easier for me as I have so much to learn!
                [SIGPIC][/SIGPIC]

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                • #38
                  Originally posted by russ View Post
                  Hi plateauhops, Welcome to Solar Panel Talk!

                  You can learn along with the rest of us! Most of us have a lot more to learn than Mike & Sunking but everyone should learn something everyday!

                  I admit it is easier for me as I have so much to learn!
                  Thanks Russ!

                  Comment


                  • #39
                    LiFePO4 batteries

                    im also thinking of going down the route of LiFePO4 batteries?
                    at the moment im running 16x 6v yuasa160en giving 2 banks of 48v (which i dont think is enough) run through tristar controllers we have a 1x2000w 12meter windturbine non gied wire that runs through a tristar-60 pwm charge controller & 12x80w solar panels but at the moment there facing west on my car port they will be shortly going up on a solar tracker system which ive yet to build this will be going through a tristar-60 mppt charge controller (on order) running all are led 240v lighting 70w hole house, tv amazing samsung 21" led monitor hocked upto hd box 25w, standerd fridge freezer 150w kick in, intrernet pc 20w, 265w day to day runs off a studer 400watt inverter & all the bigger stuff washing machine, wellwater pump etc, runs off an old ups inverter charger 3750w which has 2 massive coils in it great for big stuff at full capacity but draws to much to just leave it ticking over so its just turned on when we need it & use it with a 6kva lister diesel generator for back up an charging. cost so far on evrything

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                    • #40
                      Hi Livesly - Welcome to Solar Panel Talk!

                      Quite a project!

                      Russ
                      [SIGPIC][/SIGPIC]

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                      • #41
                        thanks russ yes it is a projeck & a half but more of a nercesity i would say! its easy to see why people get anoud on these sites there is alot off diffrent appinions on here. has no one herd of dont baleave every thing you read
                        any way after looking into my 6v 160 en yausa batteries there 160ah at 10hr rate thats good is it not?
                        & does any one no the hour rate on these 3.2 400hr LiFePO4 lithium batteries cant find it any where??

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                        • #42
                          The LiFePO4 battery uses a lithium-ion-derived chemistry and shares many of its advantages and disadvantages with other lithium ion battery chemistries.

                          However, one key advantage over other lithium-ion batteries is the superior thermal and chemical stability, which provides better safety characteristics than lithium-ion batteries with other cathode materials.[6] Due to significantly stronger bonds between the oxygen atoms in the phosphate (compared to the cobalt), oxygen is not readily released, and as a result, lithium iron phosphate cells are virtually incombustable in the event of mishandling during charge or discharge, and can handle high temperatures without decomposing.[6]

                          Lithium Iron Phosphate chemistry also offers a longer cycle life over standard lithium ion cells.[6]

                          The use of phosphates also reduces the cost, safety and environmental concerns of Cobalt cells, particularly in regards of cobalt entering the environment through improper disposal.[6]

                          One of the other major advantages for LiFePO4 when compared with LiCoO2 is higher current or peak-power rating.[7]

                          LFP batteries have some drawbacks:

                          The energy density (energy/volume) of a new LFP battery is somewhat lower than that of a new LiCoO2 battery. (14% reduction in energy density) Battery manufacturers across the world are currently working to find ways to maximize the energy storage performance and reduce size & weight.[8]
                          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 amp

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                          • #43
                            Livesley im sure the Reply given by DELTAFOX25 has answered your question in it somewhere.
                            I cant give you the answer you were looking for as that figure as you noted is usually never quoted The only figure quoted is Max Discharge <3c
                            Why do you need that figure ? to calculate what?

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                            • #44
                              thanks it was a good detailed awnser

                              yeah he did awnser my question after disifaling it all out i just wanted a simple way of working it out ie will 320ah of the LifePO4 batteries at 48v last as many or more hours of run time as my 320ah yuasu en160-6 battery bank at 48v? thats the simple question im looking for really? sorry i like things simple but i am disslexic as you may noticed from my spelling? any way after looking into it a bit it seems the batteries ive got all ready are quit good but i cant help thinking 1 day they will start to age before that happens like every one off grid i would like to look into a replacement battery bank? so if any one can sergest an afordable low mantanece battery bank id like to hear any sergestions?

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                              • #45
                                LIVERSLEY an afordable low mantanece battery bank id like to hear any sergestions? Its not an easy question to answer .. Affordable? it depends as to how you determine that.. Affordable up front?? Affordable over many years??? Standard lead acid deep cycle batteries (12v)are the lowest cost,2v cells of high ahr are far more expensive and need regular maintainance and equalizing,(not easy with solar chargers) but if good quality like Surrette will have long life if very carefully maintained. Lithium ion phosphate batteries have the potential to have very long life if used in a solar energy setup. but have very high initial cost.. but no maintainance

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