help with choice of battery. as well as Ideas in regards to charging

KenMorganKenMorgan Registered Users Posts: 56 ✭✭
I have the chance to buy one of two battery packs.  set a is a 2 volt industrial battery that is used for float on electric trains here in japan.  they are wired in series and used to propel the train to the next closest station in the event of a power outage.  so they basically float for 8 year and then replace them at that time.  they might actually get used once every two or three years during an earthquake or other disaster.  this battery bank would be a total of 24 for my 48 volt system along with 6 spares that I would float as a 12 volt system in case one or two of the used batteries proved to be bad.  total cost would be 3k for a 48volt 500 A/H bank (at 10 hours and if the calculators are correct over 700 at a 20 hour rate.)   maker GSYuasa to date has not replied once when I contacted them via their US website and the Tokyo main office will not give out charging requirements to normal folks like me...  buy a bunch of batteries from them and they will give you a charger...does me no good as I am not buying new.  these batteries tend to have a 20 year life span in float with the occasional hard drain x 1 or twice a year and are then immediately recharged.

battery bank #two is also GSYuasa but it is a flooded 48volt pack for use on electric forklifts.  it is 545 Ahs for 6 hours which equates to about 850 + at 20 hours.  once again they will give no data out (or at least they have not to this point.  however being flooded and could test SG to ensure that they are getting fully charged  Edit:  it is about the same price as the above batteries.

disadvantages of the forklift battery are that they are connected with cast lead bars from cell to cell, so if a cell were to die i would have to some how find a matching cell and then cut the bar and re-solder the lead together to replace one.

disadvantages of the AGM I can't measure the SG, and have no clue on their charging parameters and do not even know how they would react to being drawn down to say an 15-20% dod (150 amps used is my high average for my cabin when I am there, when gone it drops to a low daily average of about 60 amps) and I am way over paneled so with my old bank i could recharge fully even on cloudy days.  original bank (600 Ah) was some L8 sized agm's from China and they lasted 3 years and are on their way out. so I wanted a slightly better brand and as I am property rich but cash poor I have to shoot for one of the two above.

any thoughts?   I remember seeing that one of the members was using batteries form a train but I cannot recall who he was or what type of batteries he had (AGM vs liquid acid) 
18 JA solar 200 watt panels, 20 sharp 200 watt panels,  morningstar controller(s) and a magnum 4448 inverter with all the usual junk that goes with it. 

Comments

  • mcgivormcgivor Solar Expert Posts: 3,815 ✭✭✭✭✭✭
    edited March 11 #2
    Ten year old second hand batteries used in an application that they were not intended for, may result in going broke trying to saving money, just my personal opinion. In industry batteries are routinely replaced because it a false economy to use them beyond a certain time frame.

    For $3K  32 × 280 Ah LiFePo4 cells could be purchased to make a 560 Ah 48V nominal bank, new not used which would store more usable energy, allowing significantly faster charging. New lead acid would be even less expensive, they are worth something usually scrap value, I got around 10% of initial cost back.

     


    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • KenMorganKenMorgan Registered Users Posts: 56 ✭✭
    here in japan the agm cyclic version of the batteries is 6k per two volt cell new from GSYuasa.  that would cost me about 144,000 just for hte batteries.  even in the us all I see for the trojan wet cell equivlants is like 600 per battery....  even that is 14K plus  I have seen forklift batteries new in the US for about 6k but the companies i have seen to date will not ship internationally.  I have not been able to get the price for the forklift battery new but I would guess its at least 8 or 9 k here as the forklifts themselves are about 16k new.

    not saying that you are wrong.  but their has to be a better anwser.  I saw an add from the sponser on some new LiFepo4 battteries and sent this forums sponsor an email but got no reply back  its only been three days, but for something in the range of a 6K purchase i would have thought that they would have down backflips to follow up... 
    18 JA solar 200 watt panels, 20 sharp 200 watt panels,  morningstar controller(s) and a magnum 4448 inverter with all the usual junk that goes with it. 
  • mcgivormcgivor Solar Expert Posts: 3,815 ✭✭✭✭✭✭
    Are there import duties on batteries in Japan, that would be key in the logistics of ordering from China, I recently ordered CALB  LiFePo4 cells from there because there are no taxes or duty on batteries imported to Thailand.  Shipping was by air, arrived 3 days after factory capacity testing to ensure matched cells, the 200 Ah 3.2V cells were $145, there are lower cost options, but I trust my vendor based on past experiences.

    Those prices are crazy, I had considered 2V LA cells before moving to LiFePo4, a 2000Ah OPZ tubular  2V Weida cell is less than a $1000 https://shop.solaris.co.th/solar-batteries.html?battery_types=12 exchange rate 30 Bhat to $1 US, the AGM ones are slightly more, but nowhere near the prices you're looking at, could there be some environment tax?  


    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • mike95490mike95490 Solar Expert Posts: 9,274 ✭✭✭✭✭
    Float duty cells, will most likely, fail quickly when used in deep cycle (20%) application.  You are doing a service taking their trash away for them. Plan on using the dead cells as core exchange for new deep cycle batteries.

    Lead buss bars on forklift batteries.  Carefully saw the bars apart, and drill a hole to put a thru-bolt and conventional lug onto it.  do as needed.
    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 ,

  • KenMorganKenMorgan Registered Users Posts: 56 ✭✭
    Mike thats what I was thinking just wanted to see if that was a minority opinion or or not. 
    18 JA solar 200 watt panels, 20 sharp 200 watt panels,  morningstar controller(s) and a magnum 4448 inverter with all the usual junk that goes with it. 
  • KenMorganKenMorgan Registered Users Posts: 56 ✭✭
    edited March 12 #7
    mcgivor said:

    Those prices are crazy, I had considered 2V LA cells before moving to LiFePo4, a 2000Ah OPZ tubular  2V Weida cell is less than a $1000 https://shop.solaris.co.th/solar-batteries.html?battery_types=12 exchange rate 30 Bhat to $1 US, the AGM ones are slightly more, but nowhere near the prices you're looking at, could there be some environment tax?  

    Mcgivor, thanks for that link.   

    I just asked for a quote from that company in thailand.  pretty sure those are china batteries but the places I spoke with in china said they could not ship the liquid acid batteries with the acid when I asked if they could ship it separately they ignored my emails after that.  the battery without acid is fine, the acid itself is fine together they constitute haswaste from the minute it leaves the country it was made in.  if these guys have a way to do it that price point for the 600 amp hour 2 volt batteries is exactly what I was looking for.

    thats why i went with the china AGM's initially but I think i just got a shitty maker when I ordered them.  the agm's in my camper are about 10 years old and going strong.  the ones for the house lasted almost exactly 3 years.  even though I charged them at the rate according to the maker and never ran them below a DOD of 30% (70% remaining)  they are obviously on their way out.  as far as the lithium batteries go I do not want to play with assembling my own.  If they are assembled with a tested and proven BMS and the company selling them is willing to spend the time to back their crap then I would be cool.  hence the ones that AW&S are offering were attractive. (Edit:  I meant NAW&S)    I think it would have been about 6K for a set of them which would have roughly the same capacity I have now, but they did not answer any of my requests for information or quotation on shipping.



    18 JA solar 200 watt panels, 20 sharp 200 watt panels,  morningstar controller(s) and a magnum 4448 inverter with all the usual junk that goes with it. 
  • 706jim706jim Solar Expert Posts: 423 ✭✭✭✭
    While know my comments are not in the same ballpark as what you're asking here i'll tell you my story. A close relative worked for the railroad and was able to scrounge up probably 100-150 Nife cells that are used on railway wig wags. They are replaced every ten years and "should have lots of life left in them". Turns out they were not a success story with limited current and wildly fluctuating voltages.

    But they were free.

    15 years goes by.

    And now I have this giant mess of toxic batteries to dispose of and they're on our island.

    My generation is the one that went from happily dumping trash like this into the lake (who will ever know?) to recycling things properly.

    There was a happy ending though. The coast guard icebreaker was visiting and asked if we had any hazardous items to dispose of.

    My answer: "Hold my beer!"

    So in your case, it sounds like there would be considerable effort to get these batteries and there would be no recourse if they don't work out. In one of the earlier posts, someone commented that you were "getting rid of someone else's garbage".

    That's what ended up happening to me.

    Island cottage solar system with 2400 watts of panels, 1kw facing southeast 1kw facing southwest 400watt ancient Arco's facing south.Trace DR1524 MSW inverter, Outback Flexmax 80 MPPT charge controller 8 Trojan L16's. Insignia 11.5 cubic foot electric fridge. My 28th year.
  • KenMorganKenMorgan Registered Users Posts: 56 ✭✭
    edited March 12 #9
    706jim said:
    While know my comments are not in the same ballpark as what you're asking here i'll tell you my story. A close relative worked for the railroad and was able to scrounge up probably 100-150 Nife cells that are used on railway wig wags. They are replaced every ten years and "should have lots of life left in them". Turns out they were not a success story with limited current and wildly fluctuating voltages.


    So in your case, it sounds like there would be considerable effort to get these batteries and there would be no recourse if they don't work out. In one of the earlier posts, someone commented that you were "getting rid of someone else's garbage".

    That's what ended up happening to me.

    Ken
    JIm thanks for the insight.  both of these packs are lead acid so getting rid of them is not a problem.  They will buy them back at the cost of the lead, so about 30-45% of what I would be paying for them. 

    Your comments about the limited current and wildly changing voltages does catch my eye.  this is one reason I was leaning towards the forklift batteries they are liquid and are designed for deep cycle.  the company selling them does a draw down capacity test for them and the battery back showed almost full capacity on the test.  the batteries are rated for 6 hours, so they drew it down at 150 amps for 3 hours then lifted the load and recorded the voltage after it settled for 3 hours.  basically they drew 450 amps over three hours and the battery voltage still climbed to above 48 volts after resting.  they then recharged it of course so the forklift battery is probably a safer bet.  They have other sizes as well but this one at 3k is about where my wallet sits at the moment. 

    my final option is too pay about 15k and buy my way back into the grid as last year they stopped servicing my area unless you bought back in.  I will off course be responsible for any maintenance costs on my line from the minute I by back in.   I could possibly (no guarantee) convert my PV array into a grid tie system to offset costs but there is no guarantee that they would let me as they like their money.

    I need to figure out a way to s??t out cash I guess  :( 
    18 JA solar 200 watt panels, 20 sharp 200 watt panels,  morningstar controller(s) and a magnum 4448 inverter with all the usual junk that goes with it. 
  • littleharbor2littleharbor2 Solar Expert Posts: 1,599 ✭✭✭✭
    mcgivor said:
    Ten year old second hand batteries used in an application that they were not intended for, may result in going broke trying to saving money, just my personal opinion. In industry batteries are routinely replaced because it a false economy to use them beyond a certain time frame.

    For $3K  32 × 280 Ah LiFePo4 cells could be purchased to make a 560 Ah 48V nominal bank, new not used which would store more usable energy, allowing significantly faster charging. New lead acid would be even less expensive, they are worth something usually scrap value, I got around 10% of initial cost back.

     


    Not wanting to derail this thread but could you explain, in more detail this battery setup? I presume a BMS would be required but beyond that I'm pretty clueless in the lithium battery world. If I could build a battery this size for $3,000.00 I would when the time comes to replace my AGM's

    2.1 Kw Suntech 175 mono, Classic 200, Trace SW 4024 ( 15 years old  but brand new out of sealed factory box Jan. 2015), Bogart Tri-metric, 540 ah @24 volt AGM battery bank. Plenty of Baja Sea of Cortez sunshine.

  • mcgivormcgivor Solar Expert Posts: 3,815 ✭✭✭✭✭✭
    edited March 12 #11
    @KenMorgan said 
    I just asked for a quote from that company in thailand.  pretty sure those are china batteries but the places I spoke with in china said they could not ship the liquid acid batteries with the acid when I asked if they could ship it separately they ignored my emails after that.  the battery without acid is fine, the acid itself is fine together they constitute haswaste from the minute it leaves the country it was made in.  if these guys have a way to do it that price point for the 600 amp hour 2 volt batteries is exactly what I was looking for.

    Weida is a German company and the owner of Solaris is German though it is possible Weida relocated it's operationsns to China, don't know the answer to that with globalization and all. The OPzV  are the sealed version of OPzS flooded
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • KenMorganKenMorgan Registered Users Posts: 56 ✭✭
    quick bit of research shows that they are china based.... now I am really confused.

    18 JA solar 200 watt panels, 20 sharp 200 watt panels,  morningstar controller(s) and a magnum 4448 inverter with all the usual junk that goes with it. 
  • mcgivormcgivor Solar Expert Posts: 3,815 ✭✭✭✭✭✭
    You're correct, when I doing research the Hoppecke were what I was quoted for, crafty buggers using a German name, doesn't nesesarally mean they're bad though.  
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • KenMorganKenMorgan Registered Users Posts: 56 ✭✭
    edited March 14 #14
    I wish I knew enough about how these BMS's worked,  of if someone sold a reliable & safe BMS that could be scaled to the size I need I would be willing to tinker with them, but at this point in time I either have to purchase a premade battery, which is expensive as sin, or go with lead acid. 

    Regardless I have hooks in the water for both a lithium setup from NAWS, or possibly (if they can ship them)  some rolls surrettes in lead acid. 

    Still researching the requirements of shipping from the US to Japan, and or from the Company that mcgivor suggested.  They are building a quote with shipping included for the non sealed 600 Amp hour batteries. 

    One question i do have if anybody could answer it.   these large batteries are all rated at either 8 hour, or 10 hour.  GB batteries from the states has a calculator that helps to convert from 6 hour rates to any rate between 6 hours and 30 hours.  If I were to buy a battery pack from with NAWS or from Solaris, which figure should I use for battery capacity....  the stated  6, 8, 10 hour rate, or the calculated 20 hour rate?

    My inverter and my solar controllers are all based off of a 20 hour rate so the 600 Ah OPzS batteries from Solaris are listed as 600Ah at 8 hours.  through that in the calculator and it works out to be a little over 800 for a 20 hour rate.  should I punch in 600 Ah or 800 Ah?

    ken

    edited for my inability to type a single sentence without screwing up.




    littleharbor2 said:
    mcgivor said:
    Ten year old second hand batteries used in an application that they were not intended for, may result in going broke trying to saving money, just my personal opinion. In industry batteries are routinely replaced because it a false economy to use them beyond a certain time frame.

    For $3K  32 × 280 Ah LiFePo4 cells could be purchased to make a 560 Ah 48V nominal bank, new not used which would store more usable energy, allowing significantly faster charging. New lead acid would be even less expensive, they are worth something usually scrap value, I got around 10% of initial cost back.

     


    Not wanting to derail this thread but could you explain, in more detail this battery setup? I presume a BMS would be required but beyond that I'm pretty clueless in the lithium battery world. If I could build a battery this size for $3,000.00 I would when the time comes to replace my AGM's



    18 JA solar 200 watt panels, 20 sharp 200 watt panels,  morningstar controller(s) and a magnum 4448 inverter with all the usual junk that goes with it. 
  • mcgivormcgivor Solar Expert Posts: 3,815 ✭✭✭✭✭✭
    The  BMS needs to be sized according to the maximum discharge current expected, the maximum charging current in the case of dual port types, the cell protection is pretty standard on most, when I ordered mine, I provided the requirements including that it was for offgrid and they recommend one that fit the criteria.

    Building a DIY bank takes some time but is actually a lot simpler than many think, however pre manufactured batteries may be the way to go because they are packaged nicely for a clean simple installation. My reason for building my own bank was for the challenge and education received in doing so.

    Ordering from the U.S. will likely put the already expensive batteries out of reach with shipping included, the cells within are more than likely from China in the first place. There are so many available in China, I ordered my cells from there and have been extremly satisfied with not only the product but with the after sales support, this link is a sample of what's available.
    https://www.alibaba.com/countrysearch/CN/48v+600ah+lifepo4+battery.html?fsb=y&IndexArea=product_en&CatId=&SearchText=48v+600ah+lifepo4+battery&isGalleryList=G

    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • KenMorganKenMorgan Registered Users Posts: 56 ✭✭
    mcgivor said:
    The  BMS needs to be sized according to the maximum discharge current expected, the maximum charging current in the case of dual port types, the cell protection is pretty standard on most, when I ordered mine, I provided the requirements including that it was for offgrid and they recommend one that fit the criteria.

    Building a DIY bank takes some time but is actually a lot simpler than many think, however pre manufactured batteries may be the way to go because they are packaged nicely for a clean simple installation. My reason for building my own bank was for the challenge and education received in doing so.

    Ordering from the U.S. will likely put the already expensive batteries out of reach with shipping included, the cells within are more than likely from China in the first place. There are so many available in China, I ordered my cells from there and have been extremly satisfied with not only the product but with the after sales support, this link is a sample of what's available.
    https://www.alibaba.com/countrysearch/CN/48v+600ah+lifepo4+battery.html?fsb=y&IndexArea=product_en&CatId=&SearchText=48v+600ah+lifepo4+battery&isGalleryList=G

    Mcgivor, can we go offline in PM's to talk about this?  I would rally like to build my own but lack of knowledge keeps me from trying this.  some of my questions for instance are:  does the BMS stop the battery from overcharging?  does it prevent them from overheating?  can I set a solar controller at xx.xx voltage and the BMS handles it after that?  maybe i am old and stupid but it seems i seem to get conflicting data every time i search.

    I would gladly welcome some input prior to spending what little money i have available for this.  it is literaly cheaper for me to run a genset (multiple sized units depending upon load) than it is too tie back into the grid.  solar has handled it well since I made the jump other than the batteries.  my camper which was my first foray into solar is still going stron, the only difference is scale and battery maker.  my camper I used some very costly batteries bought locally... (1200.00 USD per 12 volts 200 A/h battery x 2.)  produced in China with japanese QC  no issues.  i tried to save money by going direct and got bit in the ass it seems.  I don't know enough or cannot seem to find a solid ref sourcce to reseach the whole BMS vs lithium etc.  maybe you can walk me through this and I can start a new thread to help lead others with your knowledge?

    18 JA solar 200 watt panels, 20 sharp 200 watt panels,  morningstar controller(s) and a magnum 4448 inverter with all the usual junk that goes with it. 
  • mcgivormcgivor Solar Expert Posts: 3,815 ✭✭✭✭✭✭
    edited March 14 #17
    Will send a PM message with my contact information 
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • KenMorganKenMorgan Registered Users Posts: 56 ✭✭
    mcgivor said:
    Will send a PM message with my contact information 
    thank you for your consideration and time.

    18 JA solar 200 watt panels, 20 sharp 200 watt panels,  morningstar controller(s) and a magnum 4448 inverter with all the usual junk that goes with it. 
  • jtdiesel65jtdiesel65 Solar Expert Posts: 223 ✭✭✭
    I've been doing a lot of reading on this and what I see is that:

    - AFAICT all lithium cells are from China. You may buy a name brand battery from the US or elsewhere, but when you pull off the cover you will find cells from China.
    - The cost is prohibitive unless you buy your own cells and make up your own battery.
    - Batteries from larger well known battery vendors have problems too. You are not necessarily avoiding issues by buying brand names. Some vendor batteries have limits on how that can be hooked up in series or parallel.
    - Buying DIY cells from China is a path with potential landmines. There are plenty of stories of success and plenty of stories of things going bad.  Problems can be shipping, dents, problems with battery posts, unclear age the cells, etc. It seems rare that the cells do not perform well, but it does happen.
    - If you buy cells from China to make your own battery, order an extra one or two. Make sure you get enough busbars.
    - Putting together a battery from cells requires you to top balance them. I read that some people don't do this but it seems the concensus is that it is best practice. You may need a power supply to do this correctly.
    - Putting together a battery from cells requires some extra parts you don't do with lead acid. You will need a BMS. You will need a way for the BMS to disconnect the battery on low/high temps and low/high cell voltage. For an offgrid system that seems to be either a shunt trip breaker or a contactor. If its a contactor then you need a precharge for the inverter capacitors. The contactors can weld themselves closed on inrush current. This adds cost.
    - Lithium cells ideally need to be in a controlled environment. 50-75F degrees appears be desirable.  
    - BMS can fail or not work as advertised. Best options seem to be Batrium, Orion, Rec, and maybe Chargery.  There doesn't seem to be a single definitive best. Some of the ones from China are in no way something one would want to use. Many of them have sloppy soldering and wire size that doesn't match the advertised current rating. They are cheap tho.
    - BMS integration with inverters, charge controllers, etc is hit or miss.



  • KenMorganKenMorgan Registered Users Posts: 56 ✭✭
    well I pulled the trigger yesterday on 32 of the lithium cells from china along with a BMS made by Daly.  it supposedly disconnects at overcharge measured per cell and at oer discharge measured per cell.  now to compress or not to compress?  some guys on you tube compress their batteries in the pack, others do not. 
    18 JA solar 200 watt panels, 20 sharp 200 watt panels,  morningstar controller(s) and a magnum 4448 inverter with all the usual junk that goes with it. 
  • jtdiesel65jtdiesel65 Solar Expert Posts: 223 ✭✭✭
    KenMorgan said:
    well I pulled the trigger yesterday on 32 of the lithium cells from china along with a BMS made by Daly.  it supposedly disconnects at overcharge measured per cell and at oer discharge measured per cell.  now to compress or not to compress?  some guys on you tube compress their batteries in the pack, others do not. 

    IIUC, the data sheet states greater number of cycles if they are compressed. I think it was 2000 more on 3000 expected so 5000 total. You'll want to verify those numbers. I'm not sure anyone has actually verified the number of cycles they provide. All these numbers might be marketing.  Number of cycles in a solar setup is fuzzy anyway.  Evidently they are ~1 mm difference in width comparing low to high state of charge. IMO at the very least, they need to be placed in a box or something that minimizes the stress on the busbars. Or use flexible busbars.
  • KenMorganKenMorgan Registered Users Posts: 56 ✭✭
    KenMorgan said:
    well I pulled the trigger yesterday on 32 of the lithium cells from china along with a BMS made by Daly.  it supposedly disconnects at overcharge measured per cell and at oer discharge measured per cell.  now to compress or not to compress?  some guys on you tube compress their batteries in the pack, others do not. 

    IIUC, the data sheet states greater number of cycles if they are compressed. I think it was 2000 more on 3000 expected so 5000 total. You'll want to verify those numbers. I'm not sure anyone has actually verified the number of cycles they provide. All these numbers might be marketing.  Number of cycles in a solar setup is fuzzy anyway.  Evidently they are ~1 mm difference in width comparing low to high state of charge. IMO at the very least, they need to be placed in a box or something that minimizes the stress on the busbars. Or use flexible busbars.
    Nice you re looking at other factors which are just as important... lets go people...lets work this issue and figure it out!  

    18 JA solar 200 watt panels, 20 sharp 200 watt panels,  morningstar controller(s) and a magnum 4448 inverter with all the usual junk that goes with it. 
Sign In or Register to comment.