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  1. Nobuo

    18650 spot welding -how to- ULTIMATE REPOSITORY

    Hi, I just notice your proposition, but the link does not work anymore
  2. Nobuo

    NOBUO-01, solar assisted small EV

    I finally edited the construction video, a small sum for the most important parts, hope you enjoy it! k6RLA0abmF8
  3. Nobuo

    18650 spot welding -how to- ULTIMATE REPOSITORY

    In laptop packs I've found always 0.3mm of pure nickel
  4. Nobuo

    18650 spot welding -how to- ULTIMATE REPOSITORY

    72V can easily kill a human, the more chance the more amps you receive, with a li-ion battery you have all you need to die with. However human skin has enough resistivity to don't make this kinda happen, unless you have your hands or skin covered with an enough conductivity salts solution or...
  5. Nobuo

    18650 spot welding -how to- ULTIMATE REPOSITORY

    Depends closely with your detail level construction. Cells are perfect cylinders, if you make good shapes and patterns where cells are very exactly placed, the weight will perfectly distributed if the battery have an impact for example, and is almost impossible that both insulators of two...
  6. Nobuo

    18650 spot welding -how to- ULTIMATE REPOSITORY

    Neither hot glue/ melt silicone or spot welding will make an appreciable harming heat. The important thing is the capacity of the cell to spread the heat quickly so the chemicals have not an increased temperature. All the cells is covered with a metal that will spread the heat quickly over all...
  7. Nobuo

    18650 spot welding -how to- ULTIMATE REPOSITORY

    Put the glued cells into the freezer (-18ºC or less) for 12h to 24h. Cover all into a semi-vacuum bag (standard plastic bag tied) to avoid a very high temperature change and humidity. Then you can very easily rip off them, even with your hands. You have only 5 minutes to do it properly, then you...
  8. Nobuo

    18650 spot welding -how to- ULTIMATE REPOSITORY

    OP here also the builder :o In that case specially the battery was made first sticking and welding 15p blocks, and then sticking each other up to the final shape. As you don't have time to put 8 strips of silicone and then stick the modules (silicone would harden), you are obliged exclusively...
  9. Nobuo

    18650 spot welding -how to- ULTIMATE REPOSITORY

    Very good spotted, and forgot to mention, that the cells surface make the current prefer to choose that path because its higher conductivity. When you weld layer over layer, as the surface where you are welding (nickel) is the same IR as the material you are welding to (nickel), you need...
  10. Nobuo

    18650 spot welding -how to- ULTIMATE REPOSITORY

    Basically almost the same conduction capability properties. For making a perfect IR BUS and making worth of the nickel material, I continuously weld layers in the needed places and never weld more than 0.15mm.
  11. Nobuo

    18650 spot welding -how to- ULTIMATE REPOSITORY

    Current sharing between cells inside a parallel group depends exclusively of their differences in voltages. In your example you use the same conductor for parallel and for serial, so in that case the current is not shared but conducted from one cell to the next serial cell. That example makes...
  12. Nobuo

    18650 spot welding -how to- ULTIMATE REPOSITORY

    In an ideal situation, if the cells would be true twins and have the same heat dissipation properties, and all the BUS conductors the same IR and length, the current passing through parallel conductors would be absolute zero. In practical uses there are several variables as each cells batch...
  13. Nobuo

    18650 spot welding -how to- ULTIMATE REPOSITORY

    Paralleling connections use too low current sharing, taking into account you are using new cells for the same model, you don't need even 0.15mm pure nickel. 0.1mm is more than enough for paralleling connections. You need only the right size in the main leads cathode and anode terminals...
  14. Nobuo

    18650 spot welding -how to- ULTIMATE REPOSITORY

    Which current level are you using? ( 0 - 8 ) are you referring about the static electrodes or the hand probes electrodes? for the static electrodes, on the upper side there is a strength pressure knob, adjust to the harder level. for the hand probes electrodes, try to attack highly...
  15. Nobuo

    Electric Penny Board

    I think is closer as a toy than a real e-skate, I would look for further solutions
  16. Nobuo

    BMS thermal management

    nice work, though I've never seen bleeding resistors (40mA to 60mA) generating too much heat. It only happen when the battery is almost full charged and the balancing circuit activate, could you confirm this?
  17. Nobuo

    installing HS 2540 correctly

    1) usually yes, however with direct drive hubs, you can work on both directions with the same performance. 2) if putting both spacers "inside" makes the axle to be inserted with some pressure, this is just perfect. spacers could be put in both position, inside or outside the arms, however you...
  18. Nobuo

    question about kw rating for kelly controllers

    you are right, that would be a bad rating. Could you share a link with full specs of each one?
  19. Nobuo

    Digital Heinzmann sequence flashing LEDs

    a video of the blinking leds would be enormously appreciated
  20. Nobuo

    Me1003 with 600a 100v controller w/ regen

    it should work, which motor model are you using? also i'm curious about what kind of battery are you using to feed such power? :o
  21. Nobuo

    Comparative Testing Study: Commercial 18650-Format Li-Ion

    All the data show what other tests use to make in conclusion. Budget batteries never worth, if you take into account the useful energy along its lifetime, you pay more for each Wh. Otherwise all the batteries wear more or less, but it doesn't show how different is the wearing at high rates...
  22. Nobuo

    Battery meter

    Really interesting, what I don't find is what kind of displays they suggest to use to output all the data. Thanks for sharing
  23. Nobuo

    Custom BLDC Controller Closed Loop

    Could you share some of the dimensions of your casing? For such power output I don't see a real heat problem situation
  24. Nobuo

    High Amp Master Switch

    1a: the best one is to don't need to use one. For 100A the switch must be enormous and will wear fast (unless you mount any pre-charge resistor). Controller use to have a switch On / Off function, use it preferably, and disconnect the battery for storage. Otherwise you can use on of those...
  25. Nobuo

    Home made batteries

    Mainly say that for ebike purposes NCR18650B is not a recommended cell, because its weak discharge rate capability, Can be used with an acceptable performance for continuous discharge under 1.5C. About that holders, are not the ones for battery building, it will make the battery really huge as...
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