Interesting LiFePo4 battery configuration

OldManOldMan Registered Users Posts: 128 ✭✭✭
Instead of soldering hundreds of 18650 cells, prismatic cells are used. Priced incredibly right. ALL prismatics are made in China as are ALL lithium batteries. Can anyone tell me if the Battle Born batteries are 18650 packs or prismatics?
I was convinced about what direction I would go with batteries until I saw these. Now I've forgotten about those in favor of packs made with prismatics. Now I wouldn't use anything else.
Hoping eventually to have four.
How about you?

Comments

  • jonrjonr Solar Expert Posts: 1,265 ✭✭✭✭
    edited December 2018 #2
    Be careful with no-name stuff from China.  And shipping charges.   Also add an external BMS if you put more than one of these in series.

    I am available for custom hardware/firmware development

  • AmpsterAmpster Registered Users Posts: 123 ✭✭✭
    edited December 2018 #3
    I dove deeper into the site and after seeing the construction I would rather assemble a 48 volt pack from their prismatics using my own BMS. Of course that assumes I could get some assurance about the life expectancy of those cells. Overall the cost per kWh could be competitive depending on shipping.
  • OldManOldMan Registered Users Posts: 128 ✭✭✭
    Ampster said:
    I dove deeper into the site and after seeing the construction I would rather assemble a 48 volt pack from their prismatics using my own BMS. Of course that assumes I could get some assurance about the life expectancy of those cells. Overall the cost per kWh could be competitive depending on shipping.
    I had one shipping quote at $60 per pack.
  • OldManOldMan Registered Users Posts: 128 ✭✭✭
    edited December 2018 #5
    jonr said:
    Be careful with no-name stuff from China.  And shipping charges.   Also add an external BMS if you put more than one of these in series.
    Are you saying the BMS in the units are somehow defective? If you want a BMS display on the battery, ask for it.
    That said, Electric car batteries in Utah has a wonderful,  inexpensive BMS chip.

  • mcgivormcgivor Solar Expert Posts: 2,770 ✭✭✭✭✭
    OldMan said:
    Instead of soldering hundreds of 18650 cells, prismatic cells are used. Priced incredibly right. ALL prismatics are made in China as are ALL lithium batteries. Can anyone tell me if the Battle Born batteries are 18650 packs or prismatics?
    I was convinced about what direction I would go with batteries until I saw these. Now I've forgotten about those in favor of packs made with prismatics. Now I wouldn't use anything else.
    Hoping eventually to have four.
    How about you?



    These pre assembled batteries cannot be used in series to achieve a higher nominal voltage, due to internal BMS, parallel is possible, so if your system is 12V no problem.  There are pre assembled batteries at higher nominal voltages available from some manufacturers, convenient for those who don't want to build their own, however being sealed there is no access to individual cells to check cell voltage for ballance.

    Battle Born are made up of smaller cells, they confirmed that in reply to a query I made, there are pros and cons to each configuration, however for solar application prysmatic are better suited, especially in a DIY bank, IMHO.

    Price wise $360 is the single piece price, always haggle with them before ordering, it's the Chinese way, you may save a little, my negotiations resulted in the equivalent of shipping costs. For comparison my individual 100Ah cells were $65 so a DIY 12V 100Ah would be $260 add BMS plus wiring etc. the price is about the same, scaled up in voltage and capacity not as close.

    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery bank 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah FLA 24V nominal used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • jonrjonr Solar Expert Posts: 1,265 ✭✭✭✭
    > Are you saying the BMS in the units are somehow defective?

    Not defective, just not designed to create > 12V batteries.

    I am available for custom hardware/firmware development

  • OldManOldMan Registered Users Posts: 128 ✭✭✭
    jonr said:
    > Are you saying the BMS in the units are somehow defective?

    Not defective, just not designed to create > 12V batteries.
    12v is ok with me.
  • AmpsterAmpster Registered Users Posts: 123 ✭✭✭
    mcgivor said:
    ........... For comparison my individual 100Ah cells were $65 so a DIY 12V 100Ah would be $260 add BMS plus wiring etc. the price is about the same, scaled up in voltage and capacity not as close.

    That is $260 for 1200 Watts or $216 per kWh. Is that a USA price for local pickup? I have a BMS so that number works for my future expansion plans. 

  • mcgivormcgivor Solar Expert Posts: 2,770 ✭✭✭✭✭
    Ampster said:
    mcgivor said:
    ........... For comparison my individual 100Ah cells were $65 so a DIY 12V 100Ah would be $260 add BMS plus wiring etc. the price is about the same, scaled up in voltage and capacity not as close.

    That is $260 for 1200 Watts or $216 per kWh. Is that a USA price for local pickup? I have a BMS so that number works for my future expansion plans. 

    The price is FOB, shipping charges were $250 for 32×100Ah cells to Thailand, no import duties or tax on batteries here, vendors will provide shipping costs.  
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery bank 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah FLA 24V nominal used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • AmpsterAmpster Registered Users Posts: 123 ✭✭✭

    @mcgivor, in December you posted that you purchased some 100 Amphour prismatics from Alibaba. If you are happy with them, do you mind posting the name of the vendor?

    My plans are evolving and I may want to upgrade my pack sooner than I thought.

  • mcgivormcgivor Solar Expert Posts: 2,770 ✭✭✭✭✭

    The link to the supplier is http://www.aukpower.com they were very prompt with response, shipping was seamless, had two cells with labels loosing print, they sent replacements without question, without charge, so service wise very positive. The bank is performing well, no surprises, but to be honest I'm not pushing the envelope, very conservative on the maximum limitations stated in the specifications. Six months so far without deviation in voltage between cells, even when using the BMS's maximum ballancing voltage of 3.6 VPC which I did a few days ago just for curiosity's sake, they were < 20mV difference between cells. The capacity is amazing, but the most important thing, for me at least, is the lack of temperature gain, they stay well below ambient, a problem LA could never compete with.

    The lack of maintenance is is not something I'm accustomed to, however I do check every day, only to find everything is normal, though I do understand 180 +/- cycles is a fraction of the predicted life expectancy, but so far so good.

    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery bank 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah FLA 24V nominal used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • AmpsterAmpster Registered Users Posts: 123 ✭✭✭
    edited February 17 #13

    Thanks. I sent them a quote request. It is the weekend there and the tail end of Chinese New Year. I'm in no rush and have requested the quote be for slower Sea Shipping to my nearest port of Oakland.

    After sending the inquiry via the website I also found their listing on Alibaba and they have very good prices for CALBs also. There is a special on a generic 100 Ahr LFP. It has unusual dimensions but for storage I could make that shape work.

  • mcgivormcgivor Solar Expert Posts: 2,770 ✭✭✭✭✭

    The ones I got were these http://www.aukpower.com/products-info.asp?id=233 they do have different dimensions but the price was right at $65 per 100Ah cell, they honored an outdated price on Alibaba, since updated. The freedom of DOD without the need to recharge is truly a refreshing change, takes a little getting used to, today was a rare rainy day for this time of the year with around 10% normal solar input, despite this the bank voltage just holds in its mid plateau, seemingly forever. The temptation to use the generator will have to wait in order to learn the actual capacity limitations, in fact I hope tomorrow is equally low in terms of production, for nothing more than to learn the limitations, not only of the capacity reserve, but the ability to recover using solar exclusively. Yes I do have a parachute as well as a reserve, should things go wrong, but so far so good.

    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery bank 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah FLA 24V nominal used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • AmpsterAmpster Registered Users Posts: 123 ✭✭✭

    Those are the one I am looking at. I am trying to confirm an Alibaba price of $35 which is pretty cheap. Are you the guy who gave them a good rating on Alibaba fr 48 cells?

  • mcgivormcgivor Solar Expert Posts: 2,770 ✭✭✭✭✭

    The price will be closer to $70 for 100Ah, $35 must be for a smaller capacity, often they have different capacities within the same post, which can be confusing. No the feedback for 48 cells was not me.

    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery bank 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah FLA 24V nominal used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • AmpsterAmpster Registered Users Posts: 123 ✭✭✭

    Thanks, classic lost in translation situation combined with "too good to be true" LOL

    Now I am wondering if the price I saw for a CALB 100 was correct..

  • mcgivormcgivor Solar Expert Posts: 2,770 ✭✭✭✭✭

    The CALB 100Ah cells tend to be in the neighborhood of $130, based on previous research, are they twice as good? can't answer that but I do have my doubts.

    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery bank 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah FLA 24V nominal used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • AmpsterAmpster Registered Users Posts: 123 ✭✭✭

    Yeah, If I wanted to send that kind of money I would buy 96 of the cheap cells and either keep 48 in reserve or just wire them all up and the pack would be exercise half as much.

  • OldManOldMan Registered Users Posts: 128 ✭✭✭
    edited February 18 #20

    Carl from Electric Car Parts told me the Calb kind never hold as much juice as the aluminum ones.

  • AmpsterAmpster Registered Users Posts: 123 ✭✭✭

    Do I understand you mean the CALB Aluminum hold the most? Is he talking about Ahrs per kg or Ahrs per volume? I did hear that some 100Ahr CALBs were delivering as much as 120Ahrs Those were the plastic case ones.. At least that was what Jack Rickard was saying when he was selling them. LOL

    What I have discovered from a few conversations with Alibaba leads me to conclude there is a lot of binning. They attract you with good prices then tell you that the cheap ones are B cells. They try to upsell to to the premium A cells. There are still some bargains to be had out there.

    It is an interesting dilemna fo me because I am 75 years old. I might not live long enough to see the end of life of the best cells. LOL

  • OldManOldMan Registered Users Posts: 128 ✭✭✭

    Well, if they do that, I can always say no.

  • RyoliteRyolite Registered Users Posts: 3

    I'm a newbie here, I just bought eight 400AH and eight 160AH Winston Thundersky LFP's and two versions of Deligreen LFP BMS systems through Alibaba, these are for house sloar storage and camper vehicle solar storage respectively. I went with Thundersky because there is growing data that these have a longer life/higher cycle count, 8000 -10,000 cycles than the other Chinese manufacturers LFP batteries. Like Ampster, I'm up there in years and these batteries may outlast me. I highly recommend watching a 1-hour-long youtube video titled "LiFePO4 batteries 101" for anyone looking into LFP batteries, the presenter (ex-JPL engineer) appears extremely knowledgeable about LFP chemistry and specifically mentions Thundersky batteries. Winston is the only manufacturer that uses yttrium in their LFP's, which is they claim improves the cycle lifetime.

  • jonrjonr Solar Expert Posts: 1,265 ✭✭✭✭
    edited March 13 #24

    I'd tend to believe the chart here (ie, more like 2200 cycles at 80% DOD). But in an offgrid solar case, you might size it to typically have less DOD (to get reserve for cloudy days). So possibly 5000 cycles.

    https://files.ev-power.eu/inc/_img/evpower_blog/892/The_Cycle_life_of_Winston_Batttery_cells_-_versus_lead_acid1.gif

    I am available for custom hardware/firmware development

  • BB.BB. Super Moderators, Administrators Posts: 28,879 admin

    I think this is Ryolite's video he was suggesting:

    -Bill

    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • jonrjonr Solar Expert Posts: 1,265 ✭✭✭✭
    edited March 13 #26

    Interesting that he said that pulse charging of lead acid batteries is highly effective.

    His BMS explanation is quite unclear. Of course there isn't per cell monitoring/balancing. But it is often done across parallel cells (and at every series connection point).

    I am available for custom hardware/firmware development

  • AmpsterAmpster Registered Users Posts: 123 ✭✭✭
    edited March 14 #27

    Because lithium batteries have low internal resistance they are more easily paralleled than Lead Acid batteries. In fact Tesla uses 74 of them in parallel in some of its packs. I am currently paralleling 12 cells in a stionary pack made up of modules from a Nissan Leaf. Because cells in parallel will all settle at the same voltage I am not sure any measurements of the individual cell voltages while in parallel would reaveal anything.

    When i notice a group of parallel cells having a larger delta from the other groups I take that group out of the pack and test each cell on a graphing charger discharger. The difference in voltage gets larger when measured at the top or bottom of a charge/discharge cycle. That is how I cull bad cells. That is the biggest benefit of using a BMS as a data monitoring device.

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