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Pylontech US3000 batteries

  • 08-04-2021 3:10pm
    #1
    Registered Users Posts: 1,295 ✭✭✭ SD_DRACULA


    Anyone with the pylontech batteries here?
    Looking for some real life discharge value for two 3.5kw batteries (model: US3000)

    Going with the specs:

    Discharge voltage: 45~53.5
    Discharge current: 74 (Max)

    Means that the max discharge (power going to inverter) for one battery is 3922w (at 74 amps/53v) right?

    And if you have two of these batteries is the 3922w total or it scales up with two batteries? Or is the 3922w the max power taken from both batteries?

    Question is, with a Solis 6kw hybrid inverter which has 5000w charge/discharge capacity, does it mean if you run two of these batteries, when there is no solar generation (at night) then the inverter can pull full 5000w from the batteries and feed it to the house?


Comments

  • Moderators, Category Moderators, Motoring & Transport Moderators, Regional East Moderators Posts: 58,874 CMod ✭✭✭✭ unkel


    Yep to all of the above. They can go in parallel to double the power output. Where are you thinking of buying one, any link? Batteries almost certainly will never pay for themselves unless you either get a hand out from the tax payer or you build them yourself or re-purpose second hand batteries.

    "Wind is Ireland's oil" - An Taoiseach, 25/05/2022



  • Registered Users Posts: 1,295 ✭✭✭ SD_DRACULA


    Good to know they scale up :)

    https://midsummer.ie/buy/pylon-storage/pylon-3000plus
    The 4500 cycles is not great though, 2 cycles per day is about 6 years.

    And yes not sure about the payback on batteries since they will probably die before that happens but if you're maximizing the solar usage and maybe topping them up on night rate it might still be worth it, plus I'd get 1200 extra on the grant as the system is not in yet.

    These will be awesome to sort out the hot water in the future when they drop in price that is https://midsummer.ie/buy/sunamp-heat-batteries/sunamp-hwipv
    They tested them at over 40000 cycles and still going, if only lithium ones could pull that.


  • Moderators, Sports Moderators Posts: 16,073 Mod ✭✭✭✭ slave1


    SD_DRACULA wrote: »

    Question is, with a Solis 6kw hybrid inverter which has 5000w charge/discharge capacity, does it mean if you run two of these batteries, when there is no solar generation (at night) then the inverter can pull full 5000w from the batteries and feed it to the house?


    Where did you see a Solis 6kW hybrid inverter?


  • Registered Users Posts: 2,789 ✭✭✭ irishchris


    slave1 wrote: »
    Where did you see a Solis 6kW hybrid inverter?

    https://solartricity.ie/inverter-solis-hybrid-6kw/


  • Moderators, Sports Moderators Posts: 16,073 Mod ✭✭✭✭ slave1


    Good stuff, pretty sure Solis hybrids were 5kW not so long ago and 6kW was a black hole of options, maybe I'm remembering incorrectly?


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  • Registered Users Posts: 1,295 ✭✭✭ SD_DRACULA


    Yeah apparently the 6kw one is quite new.


  • Registered Users Posts: 6,396 ✭✭✭ Alkers


    SD_DRACULA wrote: »
    Good to know they scale up :)

    https://midsummer.ie/buy/pylon-storage/pylon-3000plus
    The 4500 cycles is not great though, 2 cycles per day is about 6 years.

    And yes not sure about the payback on batteries since they will probably die before that happens but if you're maximizing the solar usage and maybe topping them up on night rate it might still be worth it, plus I'd get 1200 extra on the grant as the system is not in yet.

    These will be awesome to sort out the hot water in the future when they drop in price that is https://midsummer.ie/buy/sunamp-heat-batteries/sunamp-hwipv
    They tested them at over 40000 cycles and still going, if only lithium ones could pull that.

    4,500 cycles at 3.5kWh is 5,2750kWh if electricity. Best case even if you save 20c for each of these units (which you won't), that's only €1,050 €3,150 worth of electricity. This doesn't consider losses in charging or discharging the battery and is a wildly optimistic per unit saving


  • Registered Users Posts: 229 ✭✭ E30M3


    Alkers wrote: »
    4,500 cycles at 3.5kWh is 5,250kWh if electricity. Best case even if you save 20c for each of these units (which you won't), that's only €1,050 worth of electricity. This doesn't consider losses in charging or discharging the battery and is a wildly optimistic per unit saving


    I'm not grasping your calcs here Alkers.

    4,500 cycles @ 3.5 kWh is 15,750?

    At your 20c that's €3,150.


  • Registered Users Posts: 1,295 ✭✭✭ SD_DRACULA


    I would adjust the 3.5kwh to what, 10-20% less since you can't discharge 100% anyway and I am guessing when it's cold you won't even get 80% discharge?
    Was chatting to Givenergy about their new batteries coming out before end of Q2, and they said they will have 100% discharge but 1. that can't be good for lithium and 2. maybe they're cheatting and the battery capacity is 10% more but they just don't tell you


  • Moderators, Category Moderators, Motoring & Transport Moderators, Regional East Moderators Posts: 58,874 CMod ✭✭✭✭ unkel


    SD_DRACULA wrote: »

    That's €500 per usable kWh

    Build your own from quality cells with a half decent BMS and you are looking at €140 per usable kWh, see the battery thread, several of us have done this / are doing this

    Unless of course the tax payer pays for your battery, you should let them if they insist handing you thousands of their hard earned cash :pac:

    "Wind is Ireland's oil" - An Taoiseach, 25/05/2022



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  • Registered Users Posts: 1,295 ✭✭✭ SD_DRACULA


    unkel wrote: »
    That's €500 per usable kWh

    Unless of course the tax payer pays for your battery, you should let them if they insist handing you thousands of their hard earned cash :pac:

    I have no remorse on this :D
    Given the many tens of thousands I have contributed myself

    DIY batteries sounds great but wouldn't be a fan of messing with something that can burn the house down either.


  • Registered Users Posts: 6,396 ✭✭✭ Alkers


    E30M3 wrote: »
    I'm not grasping your calcs here Alkers.

    4,500 cycles @ 3.5 kWh is 15,750?

    At your 20c that's €3,150.

    LoL, shouldn't be posting on boards when I'm half asleep.

    Have amended my figures there but also noting the spec sheet says a recommended maximum discharge of 80% reduces the units to 12,600kWh and play with the figure you expect to save per unit used from the battery to see if the financials make sense for you.

    If your night rate is 15c and the FIT would be giving you 5c, you're only really then saving 10c per kWh used from the battery.


  • Registered Users Posts: 1,627 ✭✭✭ quentingargan


    SD_DRACULA wrote: »
    Anyone with the pylontech batteries here?
    Looking for some real life discharge value for two 3.5kw batteries (model: US3000)

    Going with the specs:

    Discharge voltage: 45~53.5
    Discharge current: 74 (Max)

    Means that the max discharge (power going to inverter) for one battery is 3922w (at 74 amps/53v) right?

    And if you have two of these batteries is the 3922w total or it scales up with two batteries? Or is the 3922w the max power taken from both batteries?
    As far as I know, when the grid is present, the BMS limits current to half that 74a figure. Only in grid failure will the battery deliver that current.


  • Registered Users Posts: 1,295 ✭✭✭ SD_DRACULA


    As far as I know, when the grid is present, the BMS limits current to half that 74a figure. Only in grid failure will the battery deliver that current.

    Hmm so that's contrary to what unkel said and what I have heard also, that you can max out the 5kw on the inverter with 2 batteries.


  • Moderators, Category Moderators, Motoring & Transport Moderators, Regional East Moderators Posts: 58,874 CMod ✭✭✭✭ unkel


    SD_DRACULA wrote: »
    Hmm so that's contrary to what unkel said

    I defer to quentingargan here.
    SD_DRACULA wrote: »
    I have no remorse on this :D

    Totally, that's what subsidies are for. If they're available, grab them!

    "Wind is Ireland's oil" - An Taoiseach, 25/05/2022



  • Registered Users Posts: 1,295 ✭✭✭ SD_DRACULA


    Ok so I'm still confused about the power you can draw from two pylontech batteries
    The solis inverter has 5000w charge/discharge so can you grab that when you combine both batteries?

    The specs of the 3.5kw pylontech say this:

    Recommend Charge/Discharge Current (A) 37
    Discharge Voltage (V) 45 ~ 53.5

    So if you're going with max possible (which probably won't happen in real life) 37*53.5 = 1979.5 per battery so if you have two can you draw 3959, meaning you won't max out the 5000w on the inverter when no solar pv generation (i.e. at night)?

    This Fox battery however is rated 1C and it says it can discharge the full capacity in one hour:
    https://www.zerohomebills.com/product/fox-lv5200-5-12kwh-48v-solar-battery-module/


  • Registered Users Posts: 1,295 ✭✭✭ SD_DRACULA


    Cmon tech guys, enlighten me as I'm not sure what battery to go for :D


  • Registered Users Posts: 36,082 ✭✭✭✭ ED E


    Datasheets:
    Inv https://solartricity.ie/static/wp-content/uploads/2020/11/Datasheet_RHI-3-6K-48ES-5G.pdf
    Batt https://autosolar.es/pdf/US3000-Product-Manual-18BQSV0801.pdf

    Taking the usable cap as they rate it, 3.2kWh, x2 = 6.4kWh system cap. (120Ah)
    If the inverter is putting out 5kW on the AC side, assuming 100% efficiency for a second, thats a 94A ish draw on the packs.
    Max draw: 94A
    Packs optimal: 74A (37x2)
    Packs Max: 148A (74 x2)

    So with two US3000s your worst day is slightly over optimal but way below their rated max. Less than 1C.



    Payback still doesnt make sense....

    PS: Unkel pls verify my napkin maths.


  • Registered Users Posts: 1,295 ✭✭✭ SD_DRACULA


    There is a new model US3000C which has 95% DOD so it would be more like 6.7kwh charge between the two.
    Hmm so I'm looking at max 3.5kw (37a * 48v * 2 batteries) continuous for the two and would need three of them to hit the 5kw discharge of the inverter in that case?

    Also the 48v from each battery, do they stack like the amps?
    i.e. (48*2)v*74a = 7104w?

    Is anyone running two pylontechs that can verify this for me? Either the 2.4kw or the 3.5kw would do


  • Registered Users Posts: 1,295 ✭✭✭ SD_DRACULA


    Ok so I went straight to the source (pylontech) and I:
    The max. constant current of US3000C is 37A, so the max. constant power is around 1.8kw. If you have only two batteries, while the power of the inverter is larger than total power of the batteries, the battery will work at max. constant power. If you have more than 3 US3000C connected to one 5kva inverter, the max. power of the batteries will be 5kw

    So there you have it the 3.5kwh battery max discharge is 1.8kw and for the 2.4kwh it is 1.2kw so basically 0.5C for anyone trying do the maths to max out your inverter


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  • Registered Users Posts: 2,789 ✭✭✭ irishchris


    Could do with some advise here from pylon owners. Added a2.4kw battery today. Charged from Solar earlier to 100% and discharged to 20 but notice it is now using grid to charge up again. What have I missed here or is there something I need to select to stop this?


  • Registered Users Posts: 1,627 ✭✭✭ quentingargan


    irishchris wrote: »
    Could do with some advise here from pylon owners. Added a2.4kw battery today. Charged from assist rather to 100% and discharged to 20 but notice it is now using grid to charge up again. What have I missed here or is there something I need to select to stop this?
    Is that your first battery? Check that time charging is set to STOP not RUN. Advanced menu (pm me if you don't know the password)


  • Registered Users Posts: 2,789 ✭✭✭ irishchris


    Is that your first battery? Check that time charging is set to STOP not RUN. Advanced menu (pm me if you don't know the password)

    Yes first battery. Timed charging it set to stop. Really baffled on this as it is doing it again this morning. Attached photos of the two screens. Any help greatly appreciated
    https://ibb.co/n6nFCnQ
    https://ibb.co/nr42Zzg


  • Registered Users Posts: 1,627 ✭✭✭ quentingargan


    irishchris wrote: »
    Yes first battery. Timed charging it set to stop. Really baffled on this as it is doing it again this morning. Attached photos of the two screens. Any help greatly appreciated
    https://ibb.co/n6nFCnQ
    https://ibb.co/nr42Zzg
    When you select the battery type, I assume it is PYLON LV. What are the figures for SOC, and Force Charge? Is the storage mode set to reserve by any chance? I would also, in that time charge screen change the start and stop times so they are the same (zero hours in right column) though the STOP option should over-rule that.

    I would particularly check that it isn't set to reserve mode, which keeps the batteries full to about 60% (or whatever you set it to) and ready for a power cut.


  • Registered Users Posts: 2,789 ✭✭✭ irishchris


    When you select the battery type, I assume it is PYLON LV. What are the figures for SOC, and Force Charge? Is the storage mode set to reserve by any chance? I would also, in that time charge screen change the start and stop times so they are the same (zero hours in right column) though the STOP option should over-rule that.

    I would particularly check that it isn't set to reserve mode, which keeps the batteries full to about 60% (or whatever you set it to) and ready for a power cut.

    Many many thanks for that Quentingargan. For some reason reserve mode was on also. Switched it off and seems to have resolved it. Head was fried trying to figure it out so really appreciate that, thank you


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