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Energy storage 18650 up to 24kWh class Paragon, Powerwall

remzibi 18312 153
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Treść została przetłumaczona polish » english Zobacz oryginalną wersję tematu
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  • #151 21637020
    remzibi
    Level 24  
    stasiekb100 wrote:
    What model of thermal imaging camera do you have?
    .

    HT18+, but they can also be found under the name GW256
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  • #152 21658400
    djfazee
    Level 15  
    I've got a couple of hundred recycled cells from scooters, I've been wondering what to do with them all this time and finally the author gave me the inspiration ;-) now just to nail it down.
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  • #153 21752582
    rudzik1
    Level 10  
    Workmanship and monitoring 1st class - respect. Would you be able to add some current photos of the magazine? When filling it, did it first lay horizontally and then you raised it (I infer from the photos)? What wire did you use to connect the baskets (as a rail of individual strings)? Where did you get the baskets from that give advice (e.g. the name of the retailer on the platform in question)?
    Well, and how has the magazine performed recently? :)
  • #154 21755895
    remzibi
    Level 24  
    rudzik1 wrote:
    Execution and monitoring 1st class - respect. Would you be able to add some current photos of the magazine? When filling it was it first lying horizontally and then you raised it (I infer from the photos)? What wire did you use to connect the baskets (as a rail of individual strings)? Where did you get the baskets from that give advice (e.g. the name of the retailer on the platform in question)?
    Well, and how has the magazine performed recently? :)


    Thanks for the good word :)
    Current photo.
    Large vertical 18650 cell rack with colorful cells and white compensating wedges
    The storage unit was designed from the start to be standing, for the destination it was to be placed in, but still has castors at the bottom for easy movement if needed.
    In the photo you can also see the spacers every 4 links (the gap between the cages), and the two rows of printed wedges (the white ones),

    Yellow trapezoidal wedge on a modeling grid in 3D design software
    which compensate for the slight drooping of the links on the higher floors (the diameters of the different links are not identical).


    18650 cell holders on wooden base with copper wire interconnections.
    Connecting the baskets using 2.5mm square copper wire soldered to the basket terminals. And between the "backs" of the terminals and the terminals, sections of 0.1mm wide 5mm weld metal plates are inserted/inserted, in order to better treat the 4 terminals in one basket in case one of them has a worse solder with this 2.5mm square rail wire.
    The 4A fuses are soldered directly to the terminal blocks and on the other side to the rail.

    Black plastic holder for four cylindrical 18650 cells with metal terminals
    Baskets from Ali, I recommend the better ones with embossed lettering, the plain ones unfortunately cracked, but building a base with gutters for the baskets generally solves the cracking problem - as it prevents cracking.

    So far the storage is working great, now in November when there is no sunshine, the table is mostly milked, but if the sunshine shows up - then of course it charges up as much as it can, and lasts for the next hours/days.
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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.
Summary generated by the language model.
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