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Energy storage 18650 up to 24kWh class Paragon, Powerwall

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  • #121 21295459
    Anonymous
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  • #122 21295827
    partyzancik
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    gulson wrote:
    That is why it will be hard, because the whole of Europe is lagging behind, but I am optimistic 💪
    .
    Not all of it, just the countries that joined the eu in 2004 and after. The old 15 are fine unless you are talking about southern countries such as Greece, Spain and Portugal which have not progressed too much.

    Added after 48 [minutes]:

    @remzibi and if the cells heat up when charging you immediately dismiss it? I even when charging with tp4056 the sanyo heats up and all batteries with them I threw in the scrap.
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  • #123 21296236
    Damian_Max
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    @andrzejlisek As if you had energy storage that would last a year (xD), it would be enough to charge it with PV alone, in the sense that with the money for windmills and waterwheels you would also buy PV.

    As for the project itself I'm impressed too, you can see a great deal of time spent, congratulations!
    It's a bit inspiring, but the resulting device also carries no small risk. It could be minimised by moving the store away from the house, building it with non-flammable materials, maybe even dividing it a little into several smaller ones, monitoring it, plus some kind of automatic incident response system (disconnection / maybe fire extinguishers).
    Probably counting some reasonable man-hours, the whole project would not make economic sense, but after all, you have to do something in your spare time, and the resulting construction is certainly pleasing to the eye.

    All in all, I still have a question, maybe to the author or maybe someone else knows the answer, about the discharge of the (used?) cells themselves. Does it differ significantly from one cell to another, can it be measured somehow, should I be worried about it?
  • #124 21296246
    yogi009
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    In my opinion, assembling batteries from different cells is a bad idea. The choice of Li-Ion technology should result in the energy storage being moved to an external container (preferably an isotherm). And a third point: I would consider LiFePO4 cells as less prone to fire and higher current capacity and longer life.
  • #125 21296653
    remzibi
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    andrzejlisek wrote:
    @remzibi .... Suppose you just take apart another battery from an electric scooter and find most of the cells usable, do you also do a voltage equalisation before attaching to the storage?
    .

    Yes, of course , before I weld another module of cells, they all have their voltages equalised, after about a month's storage it is usually between 4.13V-4.15V.
    I plug the next string of 14 welded modules into the magazine when the magazine is fully charged and therefore also has 4.13V-4.14V per cell (which is meticulously taken care of by the balancer), then no current flows after plugging in and there is no need to fiddle with any equalising resistors. When the sun goes down in the evening, the new added cells already discharge normally with the rest of the storage and enter their normal cycle with the whole.
  • #126 21297512
    Anonymous
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  • #127 21297621
    p.obelix
    Refrigeration equipment specialist  
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    >>21297512
    Heating a house with a heat pump means that 4000-5000 kWh are needed for the heat pump alone plus a house of 3000 kWh also you can multiply and add and it will never be enough.
  • #128 21565641
    remzibi
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    Update, it's been over a month since the magazine completely paid for itself, so after a full financial 'blip', everything is now going to the upside.
    As befits an experimental magazine - the experiment continues - and the mothballing continues :)

    Next news, sometime in March I noticed that some of the cell sockets from one batch started to crack after a while, so within two weeks (fortunately these were weeks of no sunshine at all) the storage unit was rebuilt to mechanically prevent this kind of malfunction in the future. The cracked sockets were replaced. The sockets that have the print on them are OK and nothing happens to them, but the ones from the Chinese supplier that don't have such prints and numbers - they started to break, so I LOSE to the quality of some Chinese stuff.
    Below are pics of how they break down and how I rebuilt the magazine (disassembling/disassembling it was one afternoon - I was surprised myself how quickly you can take something apart :) ) . This info would actually need to be added to the first post.

    Close-up of a damaged plastic battery holder for cylindrical cells, visible crack on the left side. Close-up of a cracked battery holder slot in a plastic cell holder. .

    Wooden energy storage frame with rows of black plastic battery holders, two white containers with additional connectors on the surface. Rows of black battery cells connected with copper busbars, arranged on a wooden background. .


    By the way, I throw in an example of a cell caught during a periodic thermal imaging inspection, a point of higher temperature by 3 degrees relative to the background, a cell that got a slight leak (after removing the tee shirt, I found a tiny electrolyte leak, a droplet). There was still a long way to go before such a cell was destroyed, maybe 3-6 months, but the thermal imaging had already caught the "dude" early enough - the cell was of course replaced immediately (without shutting down the storage), service-wise the design works.
    Here the thought really comes to mind that if the factory packs were not sealed and people/users were able to check with thermal imaging, the number of different "accidents" could be significantly reduced.

    Thermal image of a battery cell with a local temperature rise up to 25.5°C against a background of about 23°C. Thermal image of a single cell showing a hot spot with a temperature of 21.8°C.

    partyzancik wrote:

    @remzibi and if the cells heat up when charging do you just blow it off? I have had sanyo cells heat up even when charging with tp4056 and I have thrown all the batteries with them in the scrap


    Yes, with a 700mA landing current, anything above 40 deg C drops out automatically, cells usually start to heat up when charged above 3.9V, charging of course I check with thermal imaging and not "finger" :) .
    Example photo of a thermo cell which will be discarded in a moment

    Thermal image showing three cells in a charger, one cell reaching 38.3°C.
  • #129 21565809
    gulson
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    Thank you so much for updating the topic and sharing the link control. I can see that you are approaching this professionally, one can take example from you.
  • #130 21583514
    partyzancik
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    @remzibi And how about cells discharged to zero ? Do you manage to pick them up and use them normally or trash them ?
  • #131 21583771
    Strumien swiadomosci swia
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    Yes will raise the link but it is a lottery what happens afterwards.
  • #132 21583778
    LEDówki
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    >>21583514 It depends on how long they have been discharged. They certainly lose a lot of capacity and their internal resistance increases. I disposed of two of these. They seemed to charge, but not fully and they were hot. About 10% of the original capacity remained. This is why PCM protection circuits are used for these batteries, so that such situations do not occur.
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  • #133 21583803
    yogi009
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    There is no room for debate here. A cell discharged in this way does not return to its normal condition and must be replaced.
  • #134 21583910
    kkknc
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    Even if it doesn't heat up. It still has a fair amount of capacity loss.
  • #135 21584666
    remzibi
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    partyzancik wrote:
    @remzibi And how about cells discharged to zero ? Can you pick them up and use them normally or trash them ?
    .

    Yes, all cells discharged to 0V or almost 0V I try to "pick up" as much as possible, firstly by boosting with a current of 50-100mA to a voltage of about 2.8V 2.9V 3V, then a short rest of about 24 hours to see if there is a rapid self-discharge, and if the voltage has dropped (there is self-discharge) then the cell is immediately discarded. If the voltage holds, the cell is put through its normal cycle of testing for heating, capacity, Rwew, one month's ageing, etc.
    Approximately 65% of fully discharged cells normally pass the tests and are put into service, 35% are rejected - generally the same ratio as with cells still holding some voltage, so the fact that a cell is completely discharged is no indication of anything, and certainly not of its current condition.
    If the cell passes the tests, I do not even observe a drop in capacity, it works normally like the others and holds the parameters.
    If, however, the capacity of the cell deviates significantly from the nominal value (chemical degradation and increase in internal resistance are connected with a drop in capacity), such a cell is intended for torches, cleaning robots (converted to 18650), meters (most meters in my workshop are converted to 18650), or other undemanding power banks or powering household appliances.
  • #136 21584740
    LEDówki
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    Not everyone has that many batteries discharged to zero to do tests. I had 2 in a 5 pc battery and both had a high self-discharge current, they were heating up so I blew them out. They passed the capacity test at once. I didn't have room for the electro-waste. I have torches with NiMH batteries. The cleaning robot also has a NiMH battery pack, so the electro-waste went into the electro-waste.
    Your experience, on the other hand, proves that it is worth trying to salvage deeply discharged batteries if there is a use for them.
  • #137 21584832
    partyzancik
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    LEDówki wrote:
    The torches I have run on rechargeable NiMH batteries.
    I understand this because instead of AA and AAA cells
    LEDówki wrote:
    The cleaning robot also has a rechargeable NiMH battery,
    .

    I wonder why for an 18650 it would have more energy packed in there ? What kind of NiMH cells are in the robots ? Ordinary or high current ? I have one blue and one yellow from an Irobot and maybe I could power some power tools
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  • #138 21584862
    remzibi
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    partyzancik wrote:
    ...... on 18650 would have packed more energy in there ? What kind of NiMH cells are in the robots ? ....
    .

    I have been buying torches (ordinary or headlamps) on Ali exclusively for 18650s for many years, and I have generally tried for many years to ensure that every battery-powered item is 18650 or can be converted to do so (as there has always been free access to these cells from latop batteries or other sources).
    Some automatic cleaning robots have NiMH packs, others are Li-Ion, generally the main reason why such a robot ends up in the scrap yard is because of a dead battery, but otherwise it is usually 100% functional, the same with hoovers or other power tools - dead batteries.
    For example, converting a cleaning robot from NiMH to Li-Ion usually involves adding a 2P4S or 3P4S 18650 pack (2P or 3P in order not to force the cells with too much current) necessarily with an added BMS with built-in balancer (e.g. from Ali 4PLN/unit),
    Energy storage 18650 up to 24kWh class Paragon, Powerwall .
    and the robot's electronics control the current during charging (around usually 600-800mA), i.e. provide a CC charging component and some CV after which the BMS cuts off charging when the rated voltage is exceeded. A balancer built into the BMS ensures that the sections are charged evenly. If you let such a robot out into e.g. a If such a robot is let into e.g. a garage ( I hate cleaning in the garage, therefore I use the robot :) ) to collect all that dirt, filings and sand from the tyres, it is able to run on such a package for hours and even "lick" the floor clean :) .
    When discharged, the BMS will switch off the power supply at the appropriate moment, taking care of the health of our package - so, in fact, even the base of this robot is not needed - it can be charged e.g. with a laptop power supply (also obtained from a scrap yard). You can also add a CC/CV converter to the charger, also from Ali, adjust the CC current and the target voltage - and it will also work without any problems.
  • #139 21584968
    LEDówki
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    Torches - one for D cells or the old fashioned R20. 2 cells... The other was first for a 2S lead acid battery, but has been converted to 3 2/3 AAA batteries plus a balancer. It's been running for about 4 or 5 years. I have another 4xR14 torch, but a damaged bulb holder makes it impossible to use it other than as a night light or blinker. The fixture damaged after being lit for a long time with a krypton bulb instead of a normal bulb. One torch with a 3S lead acid battery and a halogen bulb. Maybe this one I would convert as it has a lot of space inside, but lithium ion batteries in sizes other than 18650 are expensive as they are not that popular. The torches are used either occasionally for trips to the cellar, or a little more often when evenings are short and you have to go to the energy store for fuel.

    The robot is a roomba with a battery of probably 12 SC size batteries. Supposed to be 5Ah, but to the eye it's more like 2.5-3Ah. The batteries are welded together, shrink-wrapped with plastic that fixes the position of the battery in the robot, so the clever otherwise don't put it in the other way round. You can supposedly put 4 lithium ion batteries in there, but the voltages don't match perfectly and I don't want to redo the robot. 30 minutes will go and that's usually enough for one large room. Smaller ones it covers in 10 minutes. It mainly drives on carpets. Smooth floors are handled by a dumb vacuum with a cable.
  • #140 21585425
    yvv
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    >>21565641 .

    I've installed many times temovision cameras on landfill sites which, connected to a recorder, automatically send emails if something in the field of view exceeds a set temperature. Maybe it is worth thinking about such a safety feature? Such cameras are not cheap, but maybe nevertheless. You could also program the output of the camera, or the recorder, to disconnect the cells.
  • #141 21585485
    partyzancik
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    @remzibi And from experience, which cells are most likely to fall off in terms of manufacturers ? Both in terms of temperature rise during charging , self-discharge or loss of capacity ?
  • #142 21585599
    remzibi
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    partyzancik wrote:
    @remzibi And from experience, which cells are most likely to fail as far as manufacturers are concerned ? Both in terms of temperature rise during charging , self-discharge or loss of capacity ?


    Unquestionably the worst crap are LG CHEM.
    But worn out cells are found in all manufacturers, every cell can be accused of improper operating conditions.
    If you want to reuse them, you have to test them thoroughly, depending on the result of the test, reject or allow them to continue working :) .
  • #143 21590247
    robert123
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    I have built on popular gel batteries about 30-40Ah 82V. This works with an Eaton 2.5kW UPS, which is designed to connect external batteries in addition to the internal 9Ah battery.The 2100W Farelka test ran for about an hour.
    The UPS charging can cope with such a battery, but it charges everything with only 1.5 - 2 A. (long).
    Attachments:
    • Energy storage 18650 up to 24kWh class Paragon, Powerwall IMG_20250528_151343.jpg (2.68 MB) You must be logged in to download this attachment.
    • Energy storage 18650 up to 24kWh class Paragon, Powerwall IMG_20250514_160733.jpg (3.36 MB) You must be logged in to download this attachment.
    • Energy storage 18650 up to 24kWh class Paragon, Powerwall IMG_20250528_151321.jpg (2.48 MB) You must be logged in to download this attachment.
  • #144 21595725
    robert123
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    A question from me, did a colleague do a battery test after loading the inverter with the maximum power i.e. 4KW without charging the PV panels at the same time? This would provide nice information (actual battery capacity and inverter efficiency).
  • #145 21596531
    remzibi
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    robert123 wrote:
    Question from me, did a colleague do a battery test after loading the inverter with maximum power i.e. 4KW without simultaneous charging with PV panels? This would provide nice information (actual battery capacity and inverter efficiency).
    .

    No, I did not do typical measurement tests under load.
    On the other hand, yes, it happened to load the installation with up to 4.5kW for a short time, everything worked, but detailed measurement data - no.
  • #146 21612575
    euroledwoch
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    Do you have printed baskets from Paragon ?
    What kind of plates go in there ?
  • #147 21615981
    remzibi
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    euroledwoch wrote:
    Have the baskets printed from Paragon ?
    What kind of plates go in there ?
    .
    1. no
    2. Factory-made
  • #148 21636483
    remzibi
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    remzibi wrote:
    ....... As befits an experimental magazine - the experiment continues - and the mania continues :) .........


    Update, it's been a productive year for the magazine, when did it fly by ? :) .
    A recent monthly thermal imaging check caught two cells, cause the same - cell leak,
    one cell caught and immediately replaced a month ago

    Thermal image of battery cells, one cell displaying significantly higher temperature Damaged 18650 lithium-ion cell with torn top and signs of overheating .

    and the other one caught recently, also immediately replaced

    Thermal image showing one overheated battery cell with a temperature of 34.1°C Thermal image of a battery cell with a hotspot reaching 31.8°C .
    Damaged green cylindrical cell with visible leakage and corrosion on the positive terminal .

    apart from these two "bugs", everything works fine and as intended.

    It is worth adding that these changes, are absolutely not catchable by means of voltage observations on the sections in the BMS application, temperature sensors from the BMS or other methods, only thermal imaging inspection gives the desired diagnostic results unequivocally and immediately.

    The bottom line is that all those who pin their hopes on the reliable operation of their factory stock (any Li-Ion or LiFePo4) because they think they have temperature sensors from the BMS spread across the cases - I'm afraid this is a very illusory feeling, and yet these sensors are just crap and are there - because they are there, they will show an alarm/fire when it's already too late.

    Even more so, my conviction grows that regular thermal imaging checks of the energy stores are simply essential, preferably without having to dismantle the enclosure for this activity every time, or at least without it being too time- and labour-intensive.

    As befits an experimental storage facility - the experiment continues - and continues :) .
  • #149 21636686
    partyzancik
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    remzibi wrote:
    The bottom line is that all of you who are pinning your hopes on the reliable operation of your factory stores (any Li-Ion or LiFePo4) because you think they have temperature sensors from the BMS laid out in the enclosures - I'm afraid that's a very deluded feeling, and yet those sensors are just crap and are there - because they are, they'll show an alarm/fire when it's too late.
    .
    not popularised enough they are like electric cars whose fires do not deter potential buyers anyway
  • #150 21636696
    stasiekb100
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    What model of thermal imaging camera do you have?
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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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