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Thread: Is my 24v 600Ah Battery Set up Correct

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    Default Is my 24v 600Ah Battery Set up Correct

    Hi all,
    Hope everyone is doing well.
    As you might remember I have been weighing up making a new LifePO4 battery setup.

    I have watched many YouTube videos and feel ok going ahead.
    I have not ordered anything yet - all in the AliExpress cart, LOL!!!

    Can you experts please confirm that I have a correct setup.

    16qty 304ah 3.2v cells and One BMS.





    I was going to have Two 24v packs in Parallel - would have needed Two BMS's. But I am not sure if the suggested BMS JK-B2A-8S-20P-HC will be ok with 'dual' 3.2v cells.

    EDIT: Not my drawing, just a way suggested to me.



Look Here ->
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    cant make it out to well but have a look at this link. It has all you need to know.
    Also make sure with those batteries that all are fully charged before connecting
    to each other and a top balance done.





    Last edited by fandtm666; 09-07-24 at 12:53 PM.
    dont say linux if i wanted it id install it

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    Cheers, Tiny
    "You can lead a person to knowledge, but you can't make them think? If you're not part of the solution, you're part of the problem.
    The information is out there; you just have to let it in."

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    Hi guys,
    Well, another conundrum... LOL!

    I was intentionally going for the Two 8S2P setup.

    As I had just 'Add to Cart', I realised that the Balance leads were not in the advert:

    So what has happened – before I pulled the pin on paying, is that I was going to go the Two 8 cell way, but when JIKONG (makers of the JK BMS’s), mentioned that ‘dual’ cell setup with one BMS, I had to reach out and ask for advice.
    When I asked on AliExpress about did the balance cables come with the BMS, I got this reply:

    "Dear Sir, JK-B2A-8S-20P is currently out of stock, so we recommend JKB2A8S20PHC, which can be quickly shipped today" and they supplied me with the diagram as I posted.

    NB: I had actually asked for the JK B2A24S15P BMS.

    Tiny has linked to a video whereby Ernst has suggested using a Daly parallel module.
    Would this Daly unit work ok with the JK BMS's in the pack?

    I don't know!
    I have to go the Daly BMS or the JK BMS way!
    Seems that either one has its own place. But in my best research, JK BMS's seem to be a bit better...

    The missus is boiling... LOL!

    Anyway, all good fun

    Cheers,
    GT250.

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    The Daly Parallel module will only work with 2 identical Daly BMS designed for it's use.

    The other way is using 2 JK BMS or other reputable brand & a circuit breaker between them, though I don't think the circuit breaker necessary.
    The 2 BMS when set up correctly will control everything on there own. Any fault & the BMS of the faulty bank will shut that bank down leaving the other healthy bank working. That's the attribute of a redundancy set-up that you want.
    I would bet the Daly parallel module will still let this happen, just that it will keep an eye on each BMS & possibly shut a faulty bank down earlier & it will keep both banks in a closer range of balance.

    The Daly BMS is a quality BMS if you wish to go that way of using their parallel module.
    .

    Remember back in the other thread I linked a video of the Off-Grid Garage with 3 parallel banks with different BMS, different capacities, no parallel module/s & no real problems.

    This gives me hope for my house system when it eventually needs a replacement storage system.
    Last edited by Tiny; 09-07-24 at 06:26 PM.
    Cheers, Tiny
    "You can lead a person to knowledge, but you can't make them think? If you're not part of the solution, you're part of the problem.
    The information is out there; you just have to let it in."

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    There is an article in this months Silicon Chip Magazine on solar powering an electric van that may help.
    Note the battery management module he uses.

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    Hi all,
    Thank you for the feedback. I'll be going the 8S2P way and Two BMS's.

    But is this seller in the video doing what they aren't supposed to do as with the 'Dual' battery..?


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    Quote Originally Posted by GT250 View Post
    Hi all,
    Thank you for the feedback. I'll be going the 8S2P way and Two BMS's.

    But is this seller in the video doing what they aren't supposed to do as with the 'Dual' battery..?

    Correct, he is using cells in pairs.

    It's not that you can't do it, it's just that it gives no way of balancing the individual cells.
    Cheers, Tiny
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    The information is out there; you just have to let it in."

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    Quote Originally Posted by GT250 View Post
    Hi all,
    Thank you for the feedback. I'll be going the 8S2P way and Two BMS's.
    [/url]
    that is by far the best why so the dual BMS units balance each individual cell properly.

    But remember fully charge each cell indiviually before connecting each string.
    dont say linux if i wanted it id install it

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    Hi guys,

    Yes Tiny. And this is why even 'qualified' sellers are - in some cases - doing it wrong.
    I have no doubt BTW that Ernst is doing the absolute correct way. But as we can see there are many buyers buying prebuilt kits at 'great' prices, but do not know what the actual quality of the cells are, nor the BMS, nor how it's all been wired up - unless they take it apart.
    IMO, all these 8yr/10yr warranties they provide are mumbo gumbo,, LOL!!

    Fandtm66: Yes, I will be charging them all in P - 8 per time to bring them up to full charge

    I'm not sure If I'm anal enough to do the Full Charge, then Discharge, then Full charge.... ???

    Boy oh boy, the things that one learns. It's been a Dark Wizard thing with Lead Acids/AGM's etc. But I hope that with the amount of tight charge and discharge rates and certainly having BMS's in control, it's going to be a lot easy for normal folks to have a go at doing a small - House power supplement - to be able to offset the increases in Electricity and the coming of EV's to the front...

    All good fun
    Unless you have my missus hanging around..

    Cheers,
    GT250.

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    OMG!

    I've had a reply from JIKONG (the makers, I assume), of the JK BMS's. About my reply of not wanting to use a single BMS in a 'Paired' mode of the cells, thankyou Tiny for the terminology

    He's not a Happy Jan...

    """"8s2p, connect as shown in the picture,

    Why would it be said that it cannot work properly
    8s2p, just one BMS is enough.
    What is the load power

    If your 16 series batteries are connected in series to form a 48V battery pack, JKB2A8S20PHC does not support it. If the 16 series batteries form a 24V battery pack, then. Every two batteries need to be connected in parallel, and then 8 batteries are connected in series to obtain 16 series of 24V battery packs. The voltage of parallel batteries remains unchanged, and JKB2A8S20PHC is sufficient

    Your initial idea was to divide the 16 series batteries into two 8S24V battery packs, each with a BMS installed, right
    Yesterday 16:38

    JK-B2A8S20P-HC Poland warehouse only has two pieces of inventory left
    Yesterday 16:46

    Dear, if you are not confident, you can also purchase two pieces for testing
    JK-B2A-8S-20P-HC
    JK means JK BMS BMS
    B2A means support 2A active balance current
    8S means support
    UP 4S to 8S lifepo4 battery
    UP 3S to 8S li-ion battery
    UP 6S to 8S LTO battery
    20P means support 200A charge/discharge current
    support 350A peak discharge current
    HC support Heating function and canbus function
    """""


    WOW!
    Well, I have asked him/her for a price of Two JK-B2A-8S-20P-HC BMS's - even though I think the JK B2A24S15P BMS is all I need...

    Guys, do you think there are any issues if I get the JK-B2A-8S-20P-HC BMS for my needs..?


    I've got the missus looking over my shoulder, time to go.... OW, Ow,. Ok, Ok....

  • #12
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    Wow who's pussy beaten then.lol

    I think you & the seller are on 2 different pages.

    This would be the preferred option for 1 BMS on 24v.




    This would be the preferred option for 8S2P including 2 BMS with redundancy.




    This is the 24V 2P8S option the BMS seller is expecting is simple & acceptable, however it has no redundancy it just doubles the storage capacity of the system. Which could be achieved with higher capacity different technology cells, which probably works out very expensive.
    Pick how to fit it in the area you intend to place the cells & note the heavy duty bus bars.



    In the end the choice is yours. You need to decide what is best for you.

    Not sure why you need JK B2A24S15P BMS? You don't have 24 cells unless you intend to expand capacity & go 3P8S & even then you would use only 8S lead as the 3x paralleled cells in series of 8 only can use 8 balance points.
    This begs the question why the BMS manufacturers don't make a BMS that can individually monitor cells in parallel? Like a 2P8S; or maybe they can & no one has discovered that the BMS can be setup to do so?

    The author of the cell layouts suggests that cells are not individually managed in Parallel first situations,¯\_(ツ)_/¯
    Now the author says that "The multiple BMS's don't balance between the two banks". That is technically correct, however at the top & bottom of cell voltage one BMS will stop charging or discharging it's bank & the other will continue. So at the top end of charge the first bank to reach full capacity will stop charging & the other bank will continue until both banks are fully charged, therefore all cells are balanced in both banks. They just aren't balanced across both banks, which is relatively unimportant for the system from what I'm observing in users setups. IMO
    Last edited by Tiny; 10-07-24 at 07:02 PM.
    Cheers, Tiny
    "You can lead a person to knowledge, but you can't make them think? If you're not part of the solution, you're part of the problem.
    The information is out there; you just have to let it in."

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