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Nickel Iron vs. Lead Acid - Off Grid battery debate

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  • Originally posted by russ View Post
    Old Bill - Easy to preach to the unknowing isn't it - not even any knowledge necessary possibly?
    Let's hear about anything that I ever said that is untrue.

    You may be acting like a Little man with a big problem.

    Why step on your best thread - ever?

    I did a lot to straighten this subject out.

    I know it. They know it.

    Bill Blake

    Comment


    • Originally posted by Sundetective View Post
      Let's hear about anything that I ever said that is untrue.

      You may be acting like a Little man with a big problem.

      Why step on your best thread - ever?

      Bill Blake
      Bill - Any best thread ever, which this is not and you have little to do with, outside of blather and attacks or patting your self on the back.

      You have the head problem.

      Have a nice day.
      [SIGPIC][/SIGPIC]

      Comment


      • I'm not seeing the poor charge efficiency at the bottom range of the cells. Not sure from redox chemistry why that would occur. Maybe it's some weird phenomena in Chahong's design but what it might be I cannot imagine right now? Not sure it matters but I'll repeat that my cells are 50-60 year old Edison C6 cells currently giving me 300 amp-hr of their original rated 337.5 amp-hr capacity. Perhaps they are different in their use characteristics.

        For the record...

        1) Poor charging efficiency was ONLY at the top end of the cell. Charging efficiency appeared to be a very smooth curve with near 100% coulombic efficiency at the bottom end of the cell (i.e. little charging then discharging) and then dropping to about 90% as I pushed past 150 amp-hr charging. Cummulative efficiency dropped to about 75% as I pushed past the 240 amp-hr charge mark and gets stupid low from there.

        2) I've got 20 of these C6 cells strung together running the power in my greenhouse hooked to 600 watts of solar panels. I'm running my cells for the most part in the bottom of their range. The system on the greenhouse is "tuned" so that the batteries are cycling maybe from 30% - 50% during normal days. (My greenhouse doesn't draw that much electrical energy.) More than 3 or 4 stormy days in a row and my system will "run dry" and go off-line at some points during the nights although I can't remember exactly when my last power outage was (and we've had some pretty gloomy weather lately). Weeks on end of good sun and I figure I'm probably pushing the bank into the 80% charge levels.

        3) I've only added water once this year so far to the batteries - and that was more because I was afraid I was getting forgetful, not because they were in danger of needing fluid yet. Going to be interesting to see what the summer brings as I get better light.

        Comment


        • Thanks for the heads-up, Robert.

          I haven't really progressed in my choice making since the last time I posted a reply, except that I've visited the gentleman who sells (or wants to sell) Russian NiFe batteries. A very friendly person who's in it for the transition towards sustainable mobility and society, definitely not a devil.

          We had a long talk and I explained that what I liked about the NiFe is its environmental aspects and longevity. What I liked less is that if you want to get the max out of them with regards to environmental aspects and longevity, it's best not to drain more than 30% of the capacity (similar to lead-acid), which makes them expensive. If you do take out more you have to add water and sooner or later replace the electrolyte. The latter is also a downside for me, having skipped most of my chemistry classes in high school. He told me he wasn't a fan of lithium hydroxide because of its toxicity, low availability and high costs. He preferred 100% potassium hydroxide for the electrolyte, even if that meant lower electrolyte cycle. I know hydroxide stuff is used to make soap and other cosmetic products, so maybe I can overcome this antipathy.

          Basically, right now, I'm doubting whether I should opt for good, old NiFe or ultramodern LiFeYPO4, and I told him as much. I sent him this cost comparison (prices in euros; €1 = $1.3) :

          15 x 160 Ah LiFePO4 @ 3.2 V = 7680 Wh
          DOD 60% = 4608 Wh
          Costs = € 2836 (without VAT)
          €/Wh = 0.62

          According to manufacturers you get 3000 cycles with 80%, and 5000 cycles with 70%. I would go for 60% to be on the safe side and compensate for PRomises.

          Compared to the Russian batteries:

          40 x 300 Ah NiFe @ 1.2 V = 14400 Wh
          DOD 30% = 4320 Wh
          Costs = € 5467 (without VAT)
          €/Wh = 1.27

          The LiFeYPO4 is much cheaper, takes up less space, and if it does more than 5000 cycles, you get 15 years of operation (and more if you don't mind the capacity loss). I haven't been able to find much conclusive information on environmental impacts, except that it is much better than Lithium-Ion batteries because it doesn't contain cobalt. And it doesn't explode when overcharged.

          After I sent him this comparison, he replied that he could give me a discount which would bring down the €/Wh cost to approximately 0.93. In that case he wouldn't make a profit, on condition that we would stay in close contact to exchange data and experiences and my set-up is an example for other people who would be interested in doing the same. He basically wants to gather people who want to buy NiFe batteries and then order big batches in Russia to reduce costs.

          I think the idea is kind of cool, as I'm also in it for the transition towards sustainable mobility and society etc. But I'm just not so sure about NiFe. Right now I tend towards LiFeYPO4. I know this thread is about NiFe vs Lead Acid, but it seems to me LiFe(Y)PO4 is becoming a real contender.

          Comment


          • Originally posted by Neven View Post
            ..... But I'm just not so sure about NiFe. Right now I tend towards LiFeYPO4. I know this thread is about NiFe vs Lead Acid, but it seems to me LiFe(Y)PO4 is becoming a real contender.
            Have you researched the BMS (Battery Management System) needed for LiFe(Y)PO4, it's added cost, reliability, and integration with the charger ? Just making sure you compare apples to apples.

            Although I own NiFe bank, I went through the LiFexx research a couple years ago. The BMS was a pain as most off grid installs will be much larger than what is used for vehicle installs, and beyond the capacity of the smaller BMS kits. Getting the BMS to interact properly with the charger is another issue.

            Mike
            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

            Comment


            • I know about the BMS, but must admit I haven't researched it properly. The NiFe guy also brought this up as a con of LiFeYPO4.

              BTW, Mike, maybe you already wrote about this somewhere, but how is your NiFe bank doing so far?

              Comment


              • Originally posted by Neven View Post
                ....
                BTW, Mike, maybe you already wrote about this somewhere, but how is your NiFe bank doing so far?
                I've got the carbonate test kit, but have not had time to test it. I'm using a lot of water in the
                batteries, that is a expense (distilled @ $1 gallon x 20 gallons) and a waste of half a day to get it
                into the cells

                But the lights have stayed on, the generator is run on cloudy days, and things are manageable.
                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

                Comment


                • Originally posted by Mike90250 View Post
                  I'm using a lot of water in the
                  batteries, that is a expense (distilled @ $1 gallon x 20 gallons) and a waste of half a day to get it
                  into the cells
                  You just thought you retired!
                  MSEE, PE

                  Comment


                  • Tough being retired!
                    [SIGPIC][/SIGPIC]

                    Comment


                    • Originally posted by Sunking View Post
                      You just thought you retired!
                      No he just changed jobs to being a water boy.
                      NABCEP certified Technical Sales Professional

                      [URL="http://www.solarpaneltalk.com/showthread.php?5334-Solar-Off-Grid-Battery-Design"]http://www.solarpaneltalk.com/showth...Battery-Design[/URL]

                      [URL]http://www.calculator.net/voltage-drop-calculator.html[/URL] (Voltage drop Calculator among others)

                      [URL="http://www.gaisma.com"]www.gaisma.com[/URL]

                      Comment


                      • Originally posted by Naptown View Post
                        No he just changed jobs to being a water boy.
                        Your'e a better man than I, Gunga Din.
                        ---R. Kipliing
                        SunnyBoy 3000 US, 18 BP Solar 175B panels.

                        Comment


                        • Low Temperature Ni-Fe Battery Performance

                          Many people have been asking about Ni-Fe battery efficiency and discharge performance. Please see the attached test results. Tests were performed at the National Renewable Energy Lab in Golden, CO.

                          At room temp, the batteries were charged for 7 hours at the C/5 rate. (intentional overcharge)

                          At freezing temps, the batteries were charged for only 5 hours at the C/5 rate. (no overcharge)


                          Overall, I am impressed with the battery capacity and efficiency numbers. These tests were designed to confirm battery CAPACITY, and not designed for extrapolating efficiency numbers. The fact that the freezing temperature tests were so consistent leads me to believe the data is accurate and valid. I hypothesize that we could have found a more efficient round trip at normal temps by charging for slightly less than 7 hrs.




                          Comment


                          • Ni-Fe status inquiry for Mike and watering system recommendation

                            Hi, I'm new to this site and am wondering if we can get a status update from Mike on how things are going with his Ni-Fe? It seems something is not quite right, as I don't believe they should consume the vast quantities of distilled water he described.

                            Also, on watering batteries of any kind, I was fortunate to get a battery that was equipped with a state of the art watering system from a company called BFS.

                            Basically, once the system is installed, a simple connection to a distilled reservoir is all that is needed to automatically top off all your cells. It's an awesome design and setup. Here's a link to their site. http://www.bfsgmbh.de/en

                            Cheers,
                            -Spencer

                            Comment


                            • Originally posted by Solar Spencer View Post
                              Hi, I'm new to this site and am wondering if we can get a status update from Mike on how things are going with his Ni-Fe? It seems something is not quite right, as I don't believe they should consume the vast quantities of distilled water he described. .......
                              Well, the batteries are holding up. Drinking lots of water, but whats a person to do ? Not charge them ?
                              I try to get a full charge daily, as the ChiCom batteries are only 20% nickel, and are NOT rated for deep discharging (that's why I got an 800ah set, along with their high internal resistance)
                              And today, my charge controller went ape - my 35 minute absorb time, got stuck at 217 minutes. Not sure what my charge controller was thinking, but I'm going to have to add battery water (again!) to the critters. At least it was cold and it didn't warm them up much.
                              And Morningstar seems to have outsourced their tech support to a non-working web page. Slick.

                              I charge with generator on cloudy days, and solar when it's around. If it's a cloudy week, I don't worry about fully charging, or sulfating.
                              I've got a carbonate test kit, but between keeping the place here running (the city had a fire hydrant freeze and blow out, as did half my domestic water plumbing manifolds) I've not had time to get into the testing, just charging and filling, and keeping the generators running. I've got daily logs for the last year, and my base loads are about 7Kwh daily (2 fridges, lights, computers, TV) and my harvest runs about 9 - 10Kwh, so the efficiency is not too bad.
                              So in a special situation - expected long days of clouds, not a lot of full charging, where Pb-H2So4 would suffer, they are ok, but not looking forward to the day to change electrolyte out.

                              --
                              http://tinyurl.com/LMR-Solar
                              http://tinyurl.com/LMR-BigLug
                              http://tinyurl.com/LMR-NiFe

                              Grundfos 10 SO5-9 with 3 wire Franklin motor (1/2hp 240V 1ph # 214505 ) on a timer for 3 hr noontime run - Runs off PV
                              Powerfab poletop PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe battery | 15, Evergreen 205w "12V" PV | Midnight ePanel || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT
                              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

                              Comment


                              • Originally posted by Solar Spencer View Post
                                ........ I was fortunate to get a battery that was equipped with a state of the art watering system from a company called BFS.

                                Basically, once the system is installed, a simple connection to a distilled reservoir is all that is needed to automatically top off all your cells. It's an awesome design and setup. Here's a link to their site. http://www.bfsgmbh.de/en ...
                                Ah, battery watering systems are a dime a dozen, for lead-acid banks. The NiFe banks, with the strong base electrolyte, eats the acid resistant fittings.
                                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

                                Comment

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