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Energy storage 18650 up to 24kWh class Paragon, Powerwall

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  • #61 21280163
    nemmm
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    >>21280152 .
    Unfortunately, but once the hydrogen has been ignited, this cannot be stopped other than by controlling the temperature in a large quantity of water. In this water the reaction will take place until the lithium is completely reacted. In Li-ION, the polymers are organic, which means that, in simple terms, they burn just like a plastic bottle.
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  • #62 21280164
    remzibi
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    speedy9 wrote:
    I like your design......
    ...... why did you decide to go for such a, overall rather low, usable discharge current? Boosting the current to 500mA, which is typical for standard cells, is unlikely to shorten their life noticeably, and you will need fewer cells. For what it's worth, setting the discharge to 3.3 and the charge to 4.13V is a very good step. This undoubtedly has a positive effect on the life, as Li-Ion in particular "dislikes" discharging below 20% and charging to 100%.

    Thanks for the good word :) .
    These voltage thresholds are set experimentally and work best for these cells in terms of the efficiency of the whole storage and the temperature culture of the cells. And I did quite a lot of experiments during the first tests.
    With current it is also so that there are moments of jerks and up to 600mA :) when I have to fiddle with a chainsaw in the garden and the saw cuts itself on some stick :) , or a large load such as 5kW goes on at home.
    Of course, after filling the entire storage with cells, the average currents will still decrease to a level of 150-250mA , so the cells should work for years :) .
    I don't care about reducing the number of cells - but just maximising the storage capacity, because that's where the tangible savings on bills come from, the less often I switch to "grid" the better for me :) .
  • #63 21280166
    LEDówki
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    These were secondary cells, or batteries. A charged battery will ignite readily when punctured. A discharged one will smoke slightly. The tests were conducted and documented by a Russian. Lithium ion batteries do not like overcharging. Nickel metal hydride ones, also tolerate it badly. However, in the case of nickel metal hydride, the only effect of overcharging is that the battery leaks and gases escape to the outside. The same is true of maintenance-free batteries, but there the lightning mixture escapes, so there is an explosion hazard. Batteries with liquid electrolyte, which are intrinsically non-flammable, can also explode after overcharging by splashing sulphuric acid around. This has been experienced by masters lighting a match to check the electrolyte level in a charged battery. Sparking crocodiles can also initiate the ignition of a lightning mixture.
    I have not heard of alkaline batteries exploding, but it is possible that there is such a danger.
  • #64 21280172
    remzibi
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    airman wrote:
    Hi, Have you not thought to make a 15S ? I assume you have one of the Chinese hybrids that can charge up to 60v max which gives you charging the cell up to 4v you will reduce the capacity slightly but combined with the low current draw the life increases.
    .

    No, sometimes apparently better is the enemy of good, overzealousness is worse than fascism :) , I would lose the possibility of a comparative analysis with other users who also use similar Li-Ion 14S magazines , not to say that the difference in cell efficiency between 4v and 4.13v would be significantly noticeable, and I care about the best compromise "performance"/"wear time".

    Added at 39 [minutes]:

    Janusz_kk wrote:
    ........
    so you are still a beetroot to me for those words because it decomposes water which figuratively means it 'extracts' oxygen, so I was right........


    Yes - you are right.
    With all due respect, Janusz, please don't insult others because it's not nice, start your own topic "how to blow up and set fire to any battery" and there you can bludgeon all you want 24/24 with your observations on how to set fire to any battery, but please don't make a dustbin in my thread - go and have a rest.
    An old maxim from kindergarten to remind you "whoever is called names - so are they".

    LEDówki wrote:
    ....... Charged battery readily ignites after a puncture........


    Same request, go along with Janusz to the arson thread so he has someone to argue with that he is right.
    .
    .
    The same goes for all the other potential "home-grown firefighters" .
    Please everyone, however, here maybe focus on the possibility of improving the performance of such a depot, maybe on improving the design details etc. , believe that I really know exactly the potential risks, do not underestimate and try to embrace.
    I've blown through "temi recyma" thousands of links and I know what I'm doing :) .
    Because I will start reporting to the moderator, - and there will be shame :) .
  • #65 21280224
    Anonymous
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    Anonymous
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  • #67 21280273
    remzibi
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    pawciu-85 wrote:
    remzibi wrote:
    believe that I really do know exactly the potential risks
    .

    I have my doubts about this.....
    .
    And great, everyone can have what they want - that's what freedom is all about,
    so I invite you to the thread "how to set fire to any battery"
  • #68 21280287
    Anonymous
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  • #69 21280297
    remzibi
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    pawciu-85 wrote:
    .....Ja .......
    .

    Thank you and appreciated for sharing your thoughts.
  • #70 21280378
    Anonymous
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  • #71 21280439
    remzibi
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    pawciu-85 wrote:
    ....... It has already been confirmed that Li-ion cells are fire hazardous........


    Yes I confirm, before I started building I studied the topic for a long time.
    Thank you and appreciate you for sharing your thoughts.
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  • #72 21280680
    __Maciek__
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    And back to the topic .... have you considered DIYBMS ?
  • #73 21280696
    remzibi
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    __Maciek__ wrote:
    And back on topic .... have you considered a DIYBMS ?


    Yes, but the degree of labour (time) involved in putting it together, plus the daunting cost, unfortunately disqualified it early on.
    For a moment I also considered Dale, but in the end, price-wise and functionally, the JKBMS remained on the battleground as the most optimal choice for my application.
  • #74 21280744
    andrzejlisek
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    pawciu-85 wrote:
    It has already been confirmed that Li-ion cells are fire hazardous. You cannot change the construction principles and chemical properties of these cells. You can only take care of prevention and give the monster a lot of time and attention.
    .
    Any ignition due to a reason other than damage to the case by an external force (e.g. nailing, squeezing, nicking) will be preceded by swelling of the cell. These gases that cause swelling will lead to a rupture and at that point ignition will occur, exactly as after a nail has been hammered in. It would be possible to make a check on a 3D printer in the form of a U-shape (perhaps something like this can be bought ready-made), into which a correct cell would enter freely and a swollen one would not. If we assume that we have to check every year, we could, for example, check one column every month. And since there are 14, not 12, columns, this would make checking a little less frequent than once a year. And if it's once every two years, then either one column every two months or half a column every month, and then you're not as overwhelmed with antsy work than if you went through the entire magazine in one sitting. This will allow you to find and eliminate swollen links from the magazine fairly quickly and in time, so the benefit is not only reducing the fire risk but keeping the whole magazine in good shape.
  • #75 21280749
    remzibi
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    andrzejlisek wrote:
    ........ You could make a U-shaped checker on a 3D printer ......

    The subject of cyclic inspections is brilliantly handled by thermal imaging, fast easy and pleasant, even before the cell "thinks" to start swelling, thermal imaging catches it months before it does.
    Mechanical inspection, with tools such as thermal imaging at its disposal, is out of the question due to its tediousness.
    Suppose, however, that by some miracle the gases increase in pressure - the CID fuse of the cell will work, if it doesn't work, the cell will again be visible in thermal imaging.
    If people had thermo control, accidents could be reduced to zero.
    Fortunately, we live (I have lived) in times where thermal imaging technology is already seamlessly available "under the thatched roofs" :) , and I don't have to fiddle like I used to with such inventions https://www.elektroda.pl/rtvforum/topic2398928.html
  • #76 21280754
    andrzejlisek
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    remzibi wrote:
    Yes, but the degree of labour (time) involved in assembling it, plus the daunting cost, unfortunately disqualified it early on.
    For a moment I also considered Dale, but in the end, price-wise and functionally, the JKBMS remained on the battleground as the most optimal choice for my application.


    I understand that this needs to be done 'at once', not very much can be done bit by bit as time and money allows.

    Does the charging of the magazine proceed in the same way as the charging of a single cell, i.e. connecting the voltage corresponding to the whole with current limitation, or does it proceed in a different way, e.g. a separate power supply for each column with cells connected in parallel?
  • #77 21280762
    remzibi
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    andrzejlisek wrote:
    ......
    I understand this needs to be done "all at once", not really possible to do bit by bit as time and money allows.......


    I would never fire up a warehouse without full control, so the 'partial' option is definitely out.

    andrzejlisek wrote:
    .....
    Is charging the magazine the same as charging a single cell, i.e. connecting the voltage corresponding to the whole with current limitation.....


    Charging is the responsibility of the inverter and in "buck" mode it is a normal, obviously defined CC/CV charger, "float" mode is such a defined CV containing within the defined "buck" range.
    Balancing is the responsibility of the BMS, everything is user-defined, voltage thresholds, differences to start and balancing current, so those who want can really potentiate themselves and with the accuracy to thousandths of a volt :) . There is generally a mass of settings, current, voltage and thermal alarms, etc., to choose from.
  • #78 21280969
    speedy9
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    remzibi wrote:
    before the cell "thinks" to start swelling, thermal imaging catches it months before it does.
    .
    Just wondering... have you ever seen a swollen 18650 cell? I'm seriously asking. Because I haven't. I don't think it's likely due to their construction that it would swell, because it swells from gases, and it's unlikely to build up so much that the cell would swell and the fuse would still hold.
    And by the way, I'll add an example from my life with Li-Ion. Once my Liitokala Li-500 charger 'packed' over 9900mAh into a 18650 cell! That is, more than three times the nominal capacity. I haven't used it since. And, nothing happened, but the cell was very hot. Unmanageable in my hands. I should add that it did not leak.
    https://www.elektroda.pl/rtvforum/topic3997917.html#20706340

    You might consider adding a thermometer like this on ZigBee at the top, between each battery column: https://pl.aliexpress.com/item/1005006859951460.html
    You will have continuous temperature monitoring in the app and alerts. The cost is negligible and the added security is there. Heat "goes" up, so if something bad starts to happen, the temperature will rise. When the alarm should occur would have to be tested experimentally. This could even be combined with an alarm siren :) .
  • #79 21280988
    remzibi
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    speedy9 wrote:
    ........
    Just wondering... have you ever seen a swollen 18650 cell? I'm seriously asking. Because I haven't......
    ...... I once had my Liitokala Li-500 charger "pack" over 9900mAh into an 18650 cell! ..... And, nothing happened, but the cell was very hot.......


    No, I've never seen a swollen 18650.
    .
    Anything that heats up over 40st when charging 700mA is rejected.
    .
    For fast, accurate and authoritative temperature monitoring, only thermal imaging, temp sensors I have but it's "Bronze Age" technology :) compared to thermal imaging. By the time the heat from a cell, already averaged, reaches where the sensor is, thermal imaging will catch every 0.1 deg.C months in advance and immediately when the anomaly becomes apparent.
  • #80 21281086
    speedy9
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    remzibi wrote:
    For fast, accurate and authoritative temperature monitoring, only thermal imaging, temp sensors I have but this is "Bronze Age" technology compared to thermal imaging. By the time the heat from a cell, already averaged, reaches the location where the sensor is, thermal imaging will catch every 0.1 deg.C for months in advance and immediately when the anomaly becomes apparent.

    You're absolutely right, but thermal imaging inspection requires an approach every time, and you have continuous monitoring. That was just the idea that came to me, I don't know how it would work in practice.
    remzibi wrote:
    Anything that heats up at 700mA charge over 40st is rejected.

    This heating is due to the internal resistance. Unfortunately its measurement in the Lii-500 is not very accurate and varies between channels. The Lii-600 has the same problem. I tried pairing high-current cells for a remote control boat in this way and unfortunately it did not pass the test 100%.
  • #81 21281233
    remzibi
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    speedy9 wrote:
    ...
    You're absolutely right, but thermal imaging inspection requires an approach each time, and you have continuous monitoring. That's just the idea that came to me, I don't know how it would work in practice.......
    .

    In practice, you approach with a thermal imager and see the slightest anomaly, while monitoring is supposed to be continuous and you don't see anything for months and you don't know what's really going on - unless it's only when it starts to heat up seriously (which is a bit too late), so this kind of monitoring sucks (and it's used because there's no other method and it's a bit expensive), because it works with a significant delay (we're talking about a scale of weeks), which is also the cause of potential problems.
  • #82 21281263
    speedy9
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    I wasn't suggesting abandoning thermal imaging, but rather as an add-on. Thermal imaging obviously does the job, as you write.
  • #83 21281325
    franyo_z
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    I like the design, the workmanship is very tidy and well thought out, it's clear you've already spent a ton of time, and still the selection of the remaining links. I have a question in connection with the approaching winter - your storage is in a heated room, did you somehow solve this issue? I don't think rechargeable batteries like the cold.
  • #84 21281453
    remzibi
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    franyo_z wrote:
    ...... Your storage is in a heated room, have you somehow solved this issue? The batteries don't seem to like the cold.
    .

    Yes, cells do not like frost, in this concrete room, the temperature generally never drops below 15st C.
  • #85 21281492
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  • #87 21281599
    smiga
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    With thermal imaging you can also make an automatic, although I don't know if its price will be adequate for the whole storage. I don't know how many cells you are analysing per image (the more, the cheaper the solution), but making such an image analysis, for detecting the crossing of a temperature threshold, is not a big problem. As a last resort, you could imagine one camera and some kind of system to move it (two motors - X, Y, like in a plotter). Unfortunately, increasing the resolution of the IR sensor equals a much higher price of the camera, so even a small resolution + panning will come out reasonable - e.g.: https://kamami.pl/czujniki-podczerwieni/11879...e-with-40pin-gpio-header-o-5906623427956.html. It is possible to buy a 32 x 32 pix, 32 x 24 pix solution for less than 200zl, but I don't know how to get along with it (some API, DLL would be useful), as these are usually ready to be plugged into a phone via USB.
    Helpful post? Buy me a coffee.
  • #88 21281730
    remzibi
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    smiga wrote:
    .....Finally, you could imagine one camera and some system to move it (two motors - X, Y, like in a plotter).......
    .
    I've previously provided a link here with a prototype of such a solution, but I won't elaborate on it :) https://www.elektroda.pl/rtvforum/topic2398928.html , which doesn't mean someone else can't pull it off :)

    Added after 5 [minutes]:

    cefaloid wrote:
    ..... And you have as you go to measure it daily with thermal imaging.


    pawciu-85 wrote:
    And when you have time to yourself, you think on holiday whether your storage unit is accidentally overheating.


    Yep, this is where I think I'm diagnosing obsessive neurosis, go ahead and talk it out, it brings relief :) .
    For calming neuroses, no , you don't have to go anywhere every day (but you can if you have something wrong with your head) and you don't have to think about something all the time (but you can if you have something wrong with your head). As much as possible you can think all the time not even about your - but about my storage (and imagine it in your bedroom) :) , that's what this thread is for to provoke thinking about energy storage and the consequences of climate policy :) .

    Added after 24 [minutes]: .

    pawciu-85 wrote:
    ..... Only in my humble opinion, the warehouse should be unmanned, not that you are tethered to inspection whether by thermal imaging or any other way.......


    100% of mankind would like it that way, but unfortunately all the warehouses available today have very sophisticated monitoring and control systems, if it doesn't fit - you give up the warehouse, but your neighbour won't - so you can already start thinking about it all the time (if you have something with your head) :) .
  • #89 21281801
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  • #90 21281862
    remzibi
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    pawciu-85 wrote:
    ....My warehouse is so built that I can leave it unattended for a year......


    Bravo, cheeky boy, and that's what you call an elaborate system of control and supervision, we all aspire to that ideal :) .
    You can see right away that you're still thinking about it, and don't stop :) .
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Topic summary

✨ The discussion centers on a DIY 48V energy storage system built using recycled 18650 lithium-ion cells, achieving an estimated capacity of around 12kWh currently, with plans to exceed 24kWh. The system is inspired by the "Paragon" class energy storage concept and is designed to power a home for up to two cloudy days or about 36 hours under heavy use. Key technical aspects include the use of a JKBMS battery management system with settings for 50A charge/discharge limits, voltage thresholds between 2.9V and 4.2V per cell, and thermal monitoring primarily via thermal imaging to detect early cell anomalies. The cells are carefully tested and matched by capacity and internal resistance, with a preference for cells from large vehicle packs over laptop cells due to better uniformity and reliability. Safety concerns are addressed through distributed temperature sensors, BMS protections, and housing the storage in a dedicated, fire-separated room. The discussion highlights the fire risks associated with lithium-ion cells, especially compared to lithium polymer cells, which degrade faster and are more prone to ignition. Various opinions emphasize the importance of proper cell balancing, BMS functionality, and the challenges of using mixed or random cells. The system uses a 5.5kW hybrid inverter, with charging managed in constant current/constant voltage (CC/CV) mode by the inverter and balancing handled by the BMS. Thermal imaging is preferred over continuous sensor monitoring for early detection of cell issues. The storage is kept in a heated, insulated room to avoid cold-related degradation. The conversation also touches on broader energy market dynamics, such as negative electricity pricing and the impact of renewable energy sources on grid stability. Alternative battery chemistries like LiFePO4 (LFP) are mentioned as safer and more fire-resistant options, though the DIY project focuses on repurposed 18650 Li-ion cells. The overall consensus is that while DIY 18650 storage is feasible and cost-effective, it requires meticulous cell selection, robust monitoring, and safety measures to mitigate fire risks and ensure longevity.
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FAQ

TL;DR: Magazyn 48 V 14S z odzyskanych 18650 ma dziś ok. 20 kWh, a docelowo ponad 24 kWh; autor podsumował testy słowami: „działa rewelacyjnie”. Ten FAQ jest dla osób planujących rozbudowywalny domowy magazyn PV i szukających realnych parametrów, testów ogniw, progów napięć oraz metod diagnostyki usterek. [#21276258]

Dlaczego to ważne: Ten wątek pokazuje nie teorię, lecz długoterminową eksploatację dużego magazynu DIY, z kosztami, awariami mechanicznymi, doborem BMS i praktyką serwisową.

Opcja Dane z wątku Wniosek praktyczny
Recykling 18650 w stylu Paragon 14S, 48 V, docelowo 40×6 ogniw, ponad 24 kWh łatwa rozbudowa i wymiana ogniw bez wyłączania
Li-Pol po 1–2 latach często „do wyrzucenia” według autora autor odrzucił tę chemię do magazynu domowego
LiFePO4 forumowicze wskazywali wyższą trwałość i mniejsze ryzyko pożaru alternatywa bez taniego odzysku ogniw
Ogniwa z laptopów dużo odrzutów, ok. 50% lub więcej słabe źródło do dużego magazynu
Ogniwa z e-bike/scooter packów odrzut ok. 30%, łatwiej dobrać podobne partie najlepsze źródło odzysku w tym projekcie

Kluczowy wniosek: Najważniejszą przewagą tej konstrukcji nie jest sama cena, lecz serwisowalność: można dodawać sekcje online, szybko wymieniać wadliwe ogniwa i wychwytywać wycieki termowizją, zanim pokaże je BMS. [#21276258]

Quick Facts

  • Konfiguracja magazynu to 14S, 48 V, docelowo 40 stringów po 6 ogniw; początkowo miał ok. 12 kWh, później ok. 20 kWh, a pełna wersja ma przekroczyć 24 kWh. [#21276258]
  • Progi pracy ustawiono konserwatywnie: dolny 3,3 V, górny 4,13 V na ogniwo; BMS ma zakres do 150 A, ale magazyn ustawiono na ładowanie 50 A i rozładowanie 50 A, a falownik ładuje zwykle do 40 A. [#21277727]
  • Koszt osprzętu bez ogniw wyniósł ok. 2200 PLN i obejmował m.in. BMS, ładowarki, rozładowarki, kamerę termowizyjną, koszyki, taśmę do zgrzewania, zgrzewarkę, przewody i końcówki. [#21278634]
  • Autor odrzuca ogniwa, które przy ładowaniu 700 mA przekraczają 40°C; podczas eksploatacji typowy prąd na ogniwo wynosi ok. 250–350 mA, a po pełnym zapełnieniu ma spaść do 150–250 mA. [#21565641]
  • Do kontroli termicznej użyto kamery HT18+, spotykanej też jako GW256; praktyka z wątku pokazuje, że termowizja wykryła punkt gorętszy o 3°C i dwa wycieki ogniw, których nie pokazały sekcyjne odczyty BMS. [#21637020]

How do you build a 48V 14S home energy storage system from recycled 18650 cells in the Paragon style?

Budujesz go jako stojący, rozbudowywalny magazyn 14S 48 V z równoległymi modułami dodawanymi etapami. Autor zrobił ramę przez około 3 tygodnie, użył koszyków na ogniwa, zgrzewanych połączeń, bezpieczników 4 A na stringach i hybrydowego falownika 5,5 kW. Docelowa architektura to 40 stringów po 6 ogniw, czyli układ nastawiony bardziej na pojemność i niski prąd na celę niż na maksymalną moc chwilową. Kluczowe są testy odzyskanych ogniw, selekcja temperaturą i termowizją oraz BMS z balansowaniem. [#21276258]

What is a Paragon-class battery storage design, and why do DIY builders choose it for expandable 18650 packs?

Magazyn klasy Paragon to otwarta, modułowa konstrukcja 18650 inspirowana rozwiązaniem popularyzowanym przez Leszka Kwitka, która ułatwia dokładanie ogniw i serwis bez wyłączania całego systemu. Autor wybrał ten styl właśnie dlatego, że można dodawać sekcje online, wymieniać wadliwe cele w pracującym magazynie i rozłożyć inwestycję w czasie. To ma znaczenie przy odzysku, bo napływ dobrych ogniw jest nieregularny, a pojemność rośnie etapami od ok. 12 kWh do ponad 24 kWh. [#21278484]

How are the cells arranged and connected in this 14S 48V pack, and how is the JK BMS wired to the storage?

Ogniwa są połączone jako 14 sekcji szeregowych, a każda sekcja docelowo ma 40 równoległych stringów po 6 ogniw. Autor podał schemat połączeń do JK BMS 20S z balanserem 1 A, a sam magazyn pracuje jako 14S 48 V. BMS mierzy napięcia sekcji, temperatury i steruje balansowaniem, natomiast ładowanie realizuje falownik hybrydowy w trybie CC/CV. W praktyce autor dobierał stringi pod pojemność i rezystancję wewnętrzną, a środkowe 8 stringów dostało podwójne bezpieczniki 8 A. [#21277727]

What charging and discharging voltage limits work best for recycled 18650 cells in a home storage system, and why were 3.3V to 4.13V chosen here?

W tym projekcie najlepiej sprawdził się zakres 3,3–4,13 V na ogniwo. Autor wybrał go po testach jako kompromis między użyteczną pojemnością, temperaturą pracy i trwałością odzyskanych 18650. BMS ma ustawienia skrajne 2,9–4,2 V, ale codzienna praca jest ograniczona falownikiem do 3,3–4,13 V, a rezerwa awaryjna przy braku sieci schodzi do 3,1 V na ogniwo. Dzięki temu magazyn ma niższe obciążenie chemiczne i spokojniejszą kulturę termiczną. [#21277727]

How do you test, sort, and match recovered 18650 cells for capacity, internal resistance, self-discharge, and temperature before adding them to storage?

Autor stosuje trzyetapową selekcję każdej celi. 1. Sprawdza CID, podnosi rozładowane ogniwa małym prądem i ładuje je z kontrolą temperatury. 2. Rozładowuje, ponownie ładuje prądem 700 mA, mierzy pojemność i rezystancję wewnętrzną. 3. Odkłada ogniwo na około miesiąc i ponownie ocenia samorozładowanie. Ogniwo odpada, jeśli grzeje się nadmiernie, ma słabą pojemność, wysoką rezystancję albo traci napięcie w spoczynku. Stringi są potem dobierane pod pojemność, Rwew, a nawet pochodzenie i producenta. [#21276258]

What is the safe procedure for reviving 18650 cells discharged to 0V, and how do you decide whether to reuse them or reject them?

Bezpieczna procedura polega na bardzo łagodnym podniesieniu napięcia i późniejszym pełnym teście. 1. Autor „budzi” ogniwo prądem 50–100 mA do około 2,8–3,0 V. 2. Zostawia je na około 24 godziny i sprawdza, czy nie ma szybkiego samorozładowania. 3. Jeśli napięcie trzyma, wykonuje standardowe testy pojemności, grzania, Rwew i miesięcznego starzenia. Według jego praktyki około 65% ogniw z 0 V przechodzi pełny proces, a 35% trafia do odrzutu. [#21584666]

Why did the builder choose recycled Li-Ion 18650 cells instead of Li-Pol packs or LiFePO4 cells for this energy storage project?

Wybrał odzyskane Li-Ion 18650, bo są tanie, łatwo dostępne z rozbiórki i dobrze znoszą pracę przy małym prądzie jednostkowym. O Li-Pol napisał wprost, że często szybko degenerują chemicznie i po 1–2 latach bywają do wyrzucenia mimo poprawnej eksploatacji. LiFePO4 było wskazywane przez innych jako bezpieczniejsza alternatywa, ale w tym projekcie priorytetem były niski koszt wejścia, możliwość dokładania ogniw online i wieloletnie doświadczenie autora z 18650 z odzysku. [#21276567]

What is the CID fuse inside an 18650 cell, and how does it affect safety if a cell starts failing or shorting internally?

„CID” jest wewnętrznym bezpiecznikiem ciśnieniowym w ogniwie 18650, który odłącza celę, gdy awaria powoduje wzrost ciśnienia lub nieprawidłową pracę, zmniejszając ryzyko dalszego zasilania uszkodzonego ogniwa. Autor wyjaśnił, że jeśli cela nagle zaczęłaby zwierać, najpierw powinien zadziałać właśnie CID. Jeśli nie zadziała, pozostałe ogniwa rozładują wadliwy pakiet, a potem ma zadziałać zewnętrzny bezpiecznik stringu. To nie eliminuje ryzyka, ale dodaje warstwę ochrony przy lokalnej awarii celi. [#21276258]

How does thermal imaging help detect leaking or overheating 18650 cells earlier than BMS temperature sensors in a battery storage wall?

Termowizja wykrywa pojedyncze anomalie cieplne na konkretnej celi, zanim pokażą je czujniki rozmieszczone w magazynie. Autor podał przykład ogniwa z punktem cieplejszym o 3°C względem tła; po zdjęciu koszulki znalazł mały wyciek elektrolitu i od razu wymienił celę bez wyłączania magazynu. W sierpniu 2025 opisał też dwa kolejne wycieki złapane miesięczną kontrolą termowizyjną, których nie było widać po napięciach sekcji ani po czujnikach BMS. To główny argument za regularną inspekcją całej ściany ogniw. [#21636483]

Which thermal imaging camera model was used for inspecting the battery pack, and what should you look for when choosing one for cell diagnostics?

Autor używa kamery HT18+, występującej też pod nazwą GW256. Do diagnostyki ogniw liczy się nie marketingowy opis, lecz możliwość szybkiego wychwycenia lokalnych odchyleń temperatury na pojedynczych celach i wygodna kontrola całego magazynu bez rozbierania go. W tym wątku kamera miała wykrywać nawet niewielkie różnice i służyła do okresowych przeglądów, które zastąpiły żmudne kontrole mechaniczne. To narzędzie serwisowe, nie gadżet, bo pozwala wychwycić uszkodzoną celę miesiące wcześniej. [#21637020]

What problems can cracked 18650 holders from cheap Chinese suppliers cause, and how can the rack be rebuilt to prevent this failure?

Pękające koszyki mogą osłabić podparcie ogniw i wymusić przebudowę całego magazynu. Autor zauważył w marcu pękanie części uchwytów z jednej partii; problem dotyczył nieoznaczonych koszyków od chińskiego dostawcy, podczas gdy wersje z nadrukami były stabilne. W ciągu dwóch tygodni rozebrał i przebudował magazyn tak, by mechanicznie wyeliminować to miejsce awarii, a uszkodzone uchwyty wymienił. Później doprecyzował, że zbudowanie podstawy z prowadnicami pod koszyki dodatkowo ogranicza ich pękanie. [#21565641]

How much did the frame, BMS, chargers, thermal camera, welding supplies, and other hardware cost, excluding the cells themselves?

Koszt samego osprzętu bez ogniw wyniósł około 2200 PLN. Ta kwota obejmowała ramę, BMS, ładowarki, rozładowarki, kamerę termowizyjną, koszulki, separatory, taśmę do zgrzewania, zgrzewarkę, śruby, przewody, końcówki kablowe i zaciskarkę. Autor wyraźnie rozdzielił ten budżet od czasu testowania oraz kosztu pozyskania ogniw, bo te zależą od źródła odzysku i skali selekcji. Samą konstrukcję ramy wykonał w około 3 tygodnie, pracując po 1–2 godziny popołudniami. [#21278634]

What current per cell is reasonable in a large recycled-18650 home battery, and how does keeping it around 150-350 mA affect lifespan and temperature?

W dużym magazynie z odzyskanych 18650 rozsądny jest prąd rzędu 150–350 mA na ogniwo, a chwilowo może dojść do około 600 mA przy większych skokach obciążenia. Autor opisał, że obecnie cele pracują zwykle przy 250–350 mA, a po pełnym zapełnieniu magazynu średnia ma spaść do 150–250 mA. Taki niski prąd jednostkowy poprawia kulturę temperaturową i ma wydłużyć życie ogniw, bo cały projekt jest zoptymalizowany pod pojemność i łagodne warunki pracy, nie pod agresywną moc chwilową. [#21280164]

How can you add new strings of cells to an already working 14S storage system without shutting it down, and how do you equalize voltages first?

Można to zrobić online, ale tylko po wyrównaniu napięć nowej sekcji z napięciem pracującego magazynu. Autor najpierw wyrównuje wszystkie nowe moduły do około 4,13–4,15 V po miesiącu leżakowania. Następnie czeka, aż cały magazyn będzie w pełni naładowany, czyli też będzie miał około 4,13–4,14 V na celę, i wtedy dopina nowy string 14 modułów. Dzięki temu po podłączeniu praktycznie nie płynie prąd wyrównawczy i nie trzeba używać rezystorów. [#21296653]

What options are there for adding battery storage to a PV system with a Fronius Symo 8.2 inverter, especially if it is not a hybrid model?

W tym wątku nie padła gotowa metoda podłączenia magazynu do Fronius Symo 8.2. Autor potwierdził tylko, że jego własny system działa na falowniku hybrydowym 5,5 kW i dlatego współpracuje z magazynem bezpośrednio. Na pytanie o Froniusa odpowiedział, że nie zna tego modelu i nie potrafi potwierdzić, czy jakikolwiek magazyn da się do niego dołączyć ani jak to zrobić. Praktyczny wniosek jest prosty: najpierw trzeba ustalić, czy dany Symo jest wersją hybrydową lub ma obsługę zewnętrznego magazynu. [#21278020]
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