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  • #16
    Originally posted by LiFePO4_Only View Post
    On one of your links i started eyeing up this battery,

    http://store.evtv.me/proddetail.php?...ec12400&cat=10

    Do you think it would be a good idea (basically a good economical move vs other batteries) for me to buy 2 of these and wire them in series and have a 24 volt system? I gotta say that i'm attracted to the military grade durability of them!!
    If it fits your needs go for it. It is a Bottom Balanced battery package from Jack. The cells are matched then Bottom Balanced so no BMS is required, nor could one be used. Just be sure to follow Jack's strict instructions to never charge at higher than 14.4 volts, or allow it to ever see 10 volts.

    The only down side is the expense as you are paying a premium for matched cells, Bottom Balanced, and Assembled in a 12 volt package. You are paying 78-cents per watt hour vs 45 cents buying the cells yourself and doing the work. If you are OK with the convenience of a packaged system, go for it. Jack's is a good small businessman and stands behind his products. It is where DIY EV builders buy their batteries and chargers.

    Don't cheap out on a charger. At $8000 worth of batteries last thing you want is to destroy them with a cheap charger. How do you intend to charge them? If from commercial power use a good quality CC/CV PFC charger. Jack has them, not sure about 24 volts.
    MSEE, PE

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    • #17
      Originally posted by LiFePO4_Only View Post
      Well forget that idea it says do not use in series.

      http://store.evtv.me/proddetail.php?...ec12400&cat=10

      Why?? Can i wire 2 of them in parallel then? I don't get it i thought wiring in series was very preferred and safe? Damn it 2 military durable batteries would of looked so bad ass!!
      Because they are matched cells Bottom Balanced and no way to access the individual cells for balancing. Call Jack if you want a 24 volt revision he will make you one. He will sell you two of the same modules matched up. Without the cells properly Bottom Balanced, you run a high risk of over discharging one of the two packs.

      Better yet build one yourself at almost half the cost. But do your homework before attempting. LFP batteries are not for inexperienced people and novice users.
      MSEE, PE

      Comment


      • #18
        Originally posted by Sunking View Post
        Just be sure to follow Jack's strict instructions to never charge at higher than 14.4 volts, or allow it to ever see 10 volts.
        Aren't there ways to put these protections in place automatically, don't people have set ups that will cut off charging/discharging automatically at certain points? How do people do that?


        Originally posted by Sunking View Post
        If you are OK with the convenience of a packaged system, go for it.
        Are you implying that there are some disadvantages to a packaged system, or are you just talking about being OK with the added cost of a packaged system?

        Originally posted by Sunking View Post
        Don't cheap out on a charger. At $8000 worth of batteries last thing you want is to destroy them with a cheap charger. How do you intend to charge them? If from commercial power use a good quality CC/CV PFC charger. Jack has them, not sure about 24 volts.
        From what i've read it sounds like use MTTP or go home. And i read a sizing thread that suggests that i should use a 2000 watt inverter with 24V, however i still don't know what the MTTP equivelent is for inverters, is there a certain one you'd suggest?

        I would charge this with regular AC from my wall, or from my Honda inverter generator, or from solar panels. Is there a certain spec to look for in an MTTP charger to make sure it handles both grid AC and panels? I really appreciate all the great help thank you!

        Comment


        • #19
          Originally posted by LiFePO4_Only View Post
          Aren't there ways to put these protections in place automatically, don't people have set ups that will cut off charging/discharging automatically at certain points? How do people do that?
          That is the job of the charge controller, better ones will have programmable setpoints.




          Are you implying that there are some disadvantages to a packaged system, or are you just talking about being OK with the added cost of a packaged system?
          Sunking will have to answer this one. I don't know .


          From what i've read it sounds like use MTTP or go home. And i read a sizing thread that suggests that i should use a 2000 watt inverter with 24V, however i still don't know what the MTTP equivelent is for inverters, is there a certain one you'd suggest?
          To limit the amount of current the inverter will pull from the batteries, 1000 watts per 12V increment, is a reasonable scale factor.
          1Kw @ 12V = 90A (there are some inverter losses) Trying to wrangle more than 90 amps gets pretty tough.
          2Kw @ 24V = 90A
          No 36V gear made, it's an orphan voltage.
          4Kw @ 48V = 90A


          I would charge this with regular AC from my wall, or from my Honda inverter generator, or from solar panels. Is there a certain spec to look for in an MTTP charger to make sure it handles both grid AC and panels? I really appreciate all the great help thank you!
          No, MPPT is a method of electronically tracking the PV panels minute by minute response to solar & cloud conditions to get the most possible power from them. (Mult Point Power Tracking). For your Grid or Generator powered charger, Look for efficiency and Power Factor (PF). 90% of the time, you will use the PV to recharge your bank, but in bad weather, you use the generator to Bulk charge them in the AM, and hope there is enough sun to top them off, otherwise, you run another bulk cycle in the evening. The Bulk portion of the charge, puts a lot of power into the batteries in a short time, maximizing your fuel usage.

          If you have Grid power, you do not want a battery based system, unless you have thousands of dollars to replace batteries every couple of years with, a simple Grid Tie system is better if you have reliable grid power.
          Powerfab top of pole PV mount (2) | 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

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          • #20
            Thanks! Ok my mistake, it was implied in Sunking's post that a charge controller handles all that, i misunderstood when i read it (i'm obviously a total rookie).

            Originally posted by Mike90250 View Post
            If you have Grid power, you do not want a battery based system, unless you have thousands of dollars to replace batteries every couple of years with, a simple Grid Tie system is better if you have reliable grid power.
            I am looking for part time portable use. I was under the impression that LiFePO4s can last you a life time if you aren't a constant user of them. When i say part time i mean i would go thru EDIT...2 cycles a month, i've read quotes of 5,000 cycles if you don't discharge under 20%, so 2 cycles a month should last a life time right?

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            • #21
              Originally posted by LiFePO4_Only View Post
              Aren't there ways to put these protections in place automatically, don't people have set ups that will cut off charging/discharging automatically at certain points? How do people do that?
              Sure. Depends on how you intend to charge them. The battery you looked at is intended to be used in a RV or Boat as a House battery and charged by either the engine alternator, or a charger. The voltage regulator controls the charging voltage. Being a lithium battery you have to guard against over charging and especially over discharging. Just one over discharge and it will turn your LFP battery into a BRICK you can use as a wheel chock for your RV or a Boat Anchor for your boat.

              Solar is a challenge with LFP batteries. Solar Charge Controllers are designed to be used with Lead Acid batteries, not LFP. You can modify them for Solar, but as I have warned you need to know what you are doing of you will have a expensive boat anchor on your hands.

              Originally posted by LiFePO4_Only View Post
              Are you implying that there are some disadvantages to a packaged system, or are you just talking about being OK with the added cost of a packaged system?
              Both in some respects. With LFP or any lithium battery many folks what to use a Battery Management System to control battery charging and discharging. This require you to be able to install a circuit board on each individual battery cell. Battery systems with a BMS are Top Balanced. Jack at EV VERKS and many DIY types do not use BMS because they are very expensive and shown to be the root cause of most premature failures. The battery you are looking at is Bottom Balanced, and thus no need for expensive BMS and high risk of it destroying the battery. All you have to do is never charge it higher than 14.4 volts or never let it go below 10 volts ever.

              Originally posted by LiFePO4_Only View Post
              From what i've read it sounds like use MTTP or go home. And i read a sizing thread that suggests that i should use a 2000 watt inverter with 24V, however i still don't know what the MTTP equivelent is for inverters, is there a certain one you'd suggest?
              There is no equivalent MPPT Charge Controller for an Inverter. They do not do the same thing. A MPPT Charge Controller charges a battery. An Inverter discharges a battery by converting DC to AC line voltages to power your gizmos.

              Originally posted by LiFePO4_Only View Post
              I would charge this with regular AC from my wall, or from my Honda inverter generator, or from solar panels. Is there a certain spec to look for in an MTTP charger to make sure it handles both grid AC and panels? I really appreciate all the great help thank you!
              Again you are talking Apples and Oranges. The MPPT Charge Controller is for charging your batteries and is the Magic Black Box that connects your solar panels to the batteries for charging. The Inverter connects to you rbatteries and makes AC line voltage to power your gizmos. There are some specialized Inverters called Hybrid Inverters that have built in Battery Chargers powered from commercial AC power or a generator.

              You need to tap the breaks or you are going to make some huge costly mistakes. Judging from your questions you do not have the knowledge required to pull it off. Last thing you want to start with is Lithium batteries as those are for experts with years of battery experience. You do not even know the basic elements of the equipment used.
              MSEE, PE

              Comment


              • #22
                Sounds like i should just buy a charge controller and a battery charger instead of worrying about a 2 in 1. I think i just worded my post in a confusing way. At first i said that MTTP was the best charge controller, then i was trying to ask what the 'MTTP Equivelent' of an inverter is. I simply should of just asked what the best 2000 watt pure sine inverter was. I always confuse people when i text too lol.

                But you're right i do want to step on the brakes and not spend money until i'm sure about everything i need. I really want LiFePO4s because of all it's obvious advantages (weight being a big plus alone), but man when you say something like 'People really need to know what they're doing when using lithium' that kind of scares me and makes me wonder if i should go AGM instead. Isn't one of the major advantages of LFPs safety? I've heard that people have poked holes thru them, baked them, slammed them on the ground over & over, and still there was no harm.

                EDIT...
                Hey if i do decide to go with a different battery chemistry could you tell me what would be the next best thing (like i've also heard all AGMs aren't created equal either)? But man that would really suck to go lead acid. Thank you

                I'm also thinking of just scraping the solar idea altogether, just getting the batteries, inverter, and battery charger, and just using 120VAC as my sole charging source. The panels really beef up portability size, a Honda 2000i is pretty portable

                EDIT AGAIN...
                I promise I'm not stalking you Sunking lol, I happen to come across an older post from you that said...

                "DyslexicDancer, what you are running into is there is no demand yet for charging LFP batteries with solar or wind. Well they do but for RC models or very small batteries.

                It is real easy to charge LFP batteries, in fact the charging algorithm is less complicated then any of the lead acid technologies. A lithium charger is a voltage regulated device. The difference between Lead and Litium is with lithium needs a higher voltage for each cell, tighter voltage tolerance, and terminate the charge as soon the current tapers down to 3 to 5% of initial charge. That is a very simple charger to make. All it is just a simple float voltage, and current monitor."

                Bingo!!! It is real easy and non-complicated to charge LFP batteries!! HOWEVER not with solar. So if I just want to charge with 120V via wall or inverter than I'm totally cool with those Milspec beast LiFePO4s right?? However, I am now contemplating 16 of these;

                http://www.electriccarpartscompany.c...ils_p_298.html

                EDIT AGAIN AGAIN...
                Now I read another post from you that LFP is the only way to go with solar, I'm so confused LOL, and drunk, i'm drunk and researching and confused haha...elsewhere you say LFP has problems when it comes to solar

                Comment


                • #23
                  Originally posted by LiFePO4_Only View Post
                  But you're right i do want to step on the brakes and not spend money until i'm sure about everything i need. I really want LiFePO4s because of all it's obvious advantages (weight being a big plus alone), but man when you say something like 'People really need to know what they're doing when using lithium' that kind of scares me and makes me wonder if i should go AGM instead. Isn't one of the major advantages of LFPs safety? I've heard that people have poked holes thru them, baked them, slammed them on the ground over & over, and still there was no harm.
                  Yes LiFeP04 is the safest of the Lithium family of batteries. It is the Marijuana of the hard drug scene. Does not mean it cannot be dangerous and deadly. Perhaps this video might help. CALB is the battery inside the box you were looking at.

                  MSEE, PE

                  Comment


                  • #24
                    Originally posted by LiFePO4_Only View Post
                    Hey if i do decide to go with a different battery chemistry could you tell me what would be the next best thing (like i've also heard all AGMs aren't created equal either)? But man that would really suck to go lead acid. Thank you
                    Flooded Lead Acid is the least expensive and longest lasting of the Pb world. AGM cost roughly twice as much as Flooded and only last half as long as Flooded. AGM cost about the same as Chi-Com LFP. AGM batteries are good, but you really need to justify the expense. AGM is good in mobile applications like planes where spills cannot be tolerated. They were invented for the aircraft and aerospace industries. AGM is also great for extreme cold climates. Or where one really needs very high charge and discharge rates. AGM is similar to Lithium in that you really need to be able to justify the expense when you are paying 2 to 5 times higher prices.

                    Originally posted by LiFePO4_Only View Post
                    I'm also thinking of just scraping the solar idea altogether, just getting the batteries, inverter, and battery charger, and just using 120VAC as my sole charging source. The panels really beef up portability size, a Honda 2000i is pretty portable.
                    Now you are starting to think. Solar should be the last option considered. Solar should only be used when there is no other feasible option available. Again it is justifying the expense coupled with very poor performance and limitations of solar.

                    Originally posted by LiFePO4_Only View Post
                    "DyslexicDancer, what you are running into is there is no demand yet for charging LFP batteries with solar or wind. Well they do but for RC models or very small batteries.

                    It is real easy to charge LFP batteries, in fact the charging algorithm is less complicated then any of the lead acid technologies. A lithium charger is a voltage regulated device. The difference between Lead and Litium is with lithium needs a higher voltage for each cell, tighter voltage tolerance, and terminate the charge as soon the current tapers down to 3 to 5% of initial charge. That is a very simple charger to make. All it is just a simple float voltage, and current monitor."
                    Was there a question? The statement holds true today. For solar there is not very much out there for lithium batteries (charge controllers). Again it is economics. Today economics do not work for Lithium batteries when is comes to renewable energy applications. Technology part is simple.

                    N
                    Originally posted by LiFePO4_Only View Post
                    ow I read another post from you that LFP is the only way to go with solar, I'm so confused LOL, and drunk, i'm drunk and researching and confused haha...elsewhere you say LFP has problems when it comes to solar
                    I think you took that out of context.

                    With solar and many other rechargeable battery applications Lithium is just not feasible yet and does not compete with Lead Acid. Think of it this way. If you were to come to me as a customer force to go off grid with Stand Alone Solar Battery System. I offer you two solutions:

                    1. The Flooded Lead Acid solution will cost you 60-cents per Kwh, paid in advance every 5 years with battery replacement.

                    2. The Lithium Solution will cost you $1.20 per Kwh, paid in advance every 5 years with battery replacement.

                    The market has spoken to manufactures.
                    MSEE, PE

                    Comment


                    • #25
                      Originally posted by Sunking View Post
                      DAMN!!! So much for punching holes in LiFePo4s just causing a 'Little' smoke.

                      I'm really leaning towards 16 3.2V 400AH Calbs. The equivelent FLA weight would be significant. Is there any link that you know of that is completely dripping with great information about setting up and maintaining a 48V LiFePO4 system for a newb who is too hard headed to stay away from them lol? I've also now completely ruled out solar as an input option.

                      Comment


                      • #26
                        LiFePO4_Only, I have had a look through your previous posts and can't see much information as to what exactly what your "non permanent portable type set up" is for. Maybe a short description of what you want to do and what the power requirement will be would be helpful.

                        Simon
                        Off-Grid LFP(LiFePO4) system since April 2013

                        Comment


                        • #27
                          I want back up power in case of power outages (and quite simply i am not a fan at all of lots of gasoline in my house, i do not have a garage so at most i want one 5 gallon tank). Also in the not too distant future i will have an off the grid set up of some kind (get away pad for weekends & vacations). I want a sort of 2 birds with 1 stone set up, enough power for both situations, yet not bulky enough to stop me from loading up the truck with the system for the vacation pad. This is why i really want the weight advantage of LiFePO4.

                          For awhile my plan was just to buy a Honda EU7000is and call it a day, but i'm really not a fan of gasoline (5.1 gallon tank). Actually i might still just say screw it and buy the EU7000is. However If i instead go with the battery bank power i will just buy the small Honda 2000i to go along with it (1 gallon tank). They also make tri fuel Honda and Yamaha inverter generators that can also run on propane or natural gas, so that is still a possibility that i haven't totally ruled out.

                          Comment


                          • #28
                            Originally posted by LiFePO4_Only View Post
                            I want back up power in case of power outages
                            Do you know how much time you will need backup power for and how much power you will need?

                            Also in the not too distant future i will have an off the grid set up of some kind (get away pad for weekends & vacations).
                            What is the time frame for this, one year, two years or what.
                            Do you know what your power requirements for the 'vacation pad' will be.

                            Simon
                            Off-Grid LFP(LiFePO4) system since April 2013

                            Comment


                            • #29
                              I mean by all means I can adjust and be conservative and make it work...but I can't help but to think "The more power the better!" I'm only gonna get so much anyway, you top out at 48V. Like out of the gate I want the vitals like a refrigerator, freezer, etc., but if I could move into the realm of a window AC unit blasting whenever I want etc, by all means I will be happy. Kind of talking about the off grid place. As for emergency back up at home it's kind of like owning a gun for home defense, I assume I'll never critically need it, but it's just a matter of having it and not needing it over needing it and not having it. So again the more power the better (to a degree, i see some of these insane set ups on Youtube and I know i am a total joke compared to that...my absolute hands down maximum power supply that I would ever dream of would be 48V at 1,000AH). My off grid would be for pleasure not survival, and home back up will be for an emergency that i will never see in my lifetime lol

                              Comment


                              • #30
                                Originally posted by LiFePO4_Only View Post
                                I want back up power in case of power outages (and quite simply i am not a fan at all of lots of gasoline in my house, i do not have a garage so at most i want one 5 gallon tank). Also in the not too distant future i will have an off the grid set up of some kind (get away pad for weekends & vacations).
                                Wrong answers.
                                MSEE, PE

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