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  1. Sparfuchs

    best order for cells with different voltage/ internal resistance

    hmmm, as far as I know max. 0,1 v difference is ok ? That's why I charged all the cells below 3,53v and checked every 3 minutes so they don't get over about 3,6v. So I thought, they are now balanced enough :( But even if I'd have a charger that can be set to a max. voltage of 3,6V I would not do...
  2. Sparfuchs

    best order for cells with different voltage/ internal resistance

    here is the thing... I've 392 cells, all between 3,53v and 3,63v sorted by voltage. Now I'll place them in cell holders 14 groups serial of 28 cells in parallel. Is it without any further tests absolutely irrelevant how I place them (according to voltage) or something to consider ? Edit: If it...
  3. Sparfuchs

    best order for cells with different voltage/ internal resistance

    So IF! this are all brand new cells, that were all about the same Voltage when I bought them (didn't check back then..just assuming from all the other "reclaimed" cells I had and checked for now), how it comes that some of them do now have way lower voltage then the others ?! If the only thing I...
  4. Sparfuchs

    best order for cells with different voltage/ internal resistance

    I'm so thankful for all your great help ! Just one question left: I checked all the 400 cells for internal resistance and voltage and had to charge a few of them a bit so they are all between 3,53V and 3,63V (I marked those cells to spread them in the paralell groups just to feel save). Now all...
  5. Sparfuchs

    best order for cells with different voltage/ internal resistance

    If my new "understanding" is right would that mean: If I made sure the internal resistance of all my cells is fine and have to build the pack just by knowing the voltage, it would even be a really bad idea to put all 3,4v cells together in a parallel group because there is a good chance those...
  6. Sparfuchs

    best order for cells with different voltage/ internal resistance

    I just did a try at repackr with a fictional 7s3p battery pack with values from 3500 mah to 3600 mAh (+5 mAh each) and it seems like it's not about heaving as similar mAh values of each cell in the parallel group, but about heaving as similar mah values of each parallel group in the pack right ...
  7. Sparfuchs

    best order for cells with different voltage/ internal resistance

    I just read a bit and realized that even a good charger/discharger/testers have to fully charge them and then discharge them to know the mAh of each cell, am I right ? I've 400 cells with a average voltage of 3,5v -3,6v at the moment and I absolutely haven't got the time to charge all 400...
  8. Sparfuchs

    best order for cells with different voltage/ internal resistance

    So now I've got the 400 cells I bought and WILL use 392 of them however their quality is. I do also have the mentioned Miboxxer C8 smart charger, a multimeter and soon the YR1035+ resistance tester. I just want to get the best result with my given options. So could anyone give me a "step by...
  9. Sparfuchs

    best order for cells with different voltage/ internal resistance

    Thank you so much for your detailed reply Harrisonpattm, I've already built many battery packs with reclaimed cells and the work great for now. But as the cells were all the same voltage (+- 0,02) so I didn't consider (and also didn't have equipment) for further tests back then.
  10. Sparfuchs

    best order for cells with different voltage/ internal resistance

    Thanks a lot for all your helpful replies !!! I just ordered the YR1035+ with a slot for cells to make it easier to measure (picture below). So I'll check all the 400 cells but how do I use the results ? As it will be a 14s28p pack I'll have 14 different "voltage categories" so I can combine...
  11. Sparfuchs

    best order for cells with different voltage/ internal resistance

    Hallo EV friends, I'm about to build a 14s28p battery pack with "reclaimed" (sellers definition of reclaimed below) 21700 samsung 50e cells. my main question is if there is a "best" cell combination order to consider by knowing the internal resistance and the voltage of each cell if they...
  12. Sparfuchs

    reduce voltage drop between battery and controller

    well, your battery is a 21s 97Ah battery..mine is a 19s 16AH battery. I really doubt that you've ever had even approximately voltage drop to avaluate what the sabvoton does in my case, right ?
  13. Sparfuchs

    Controller tuning or mods for more volt or amps ?

    I've some more questions to the bypass mod: So this sensors in the controller only measure the amps of two phase wires to the motor, right ? So does the controller know by calculation/physical law how the phase amps are related to the drawn dc amps or how does it make sure it uses my dc...
  14. Sparfuchs

    reduce voltage drop between battery and controller

    I'm not that sure anymore if this solves my problem because even if I bypass the sensors it will still notice the voltage drop and might lower the output until "it's happy" with the drop. So if it now reduces it's phase amps at big voltage drop for example by 50 amps, isn't it likely that if I'd...
  15. Sparfuchs

    reduce voltage drop between battery and controller

    I do use a adjustable charger and charge it to 4,1v per cell with 24amps. When it's done I charge it to 4,16v per cell with just a few amps. Seems safe and good for for cycle life to me and is definitely fast enough :)
  16. Sparfuchs

    reduce voltage drop between battery and controller

    Thanks for your recommendations, But there are insulation rings, they are just under the insulation wrap in my case. Hot glue is a common method for space saving builds but in my case it was mainly to keep the cells into place while spotwelding. I made sure the pack can't move in the case at...
  17. Sparfuchs

    reduce voltage drop between battery and controller

    Awesome, that's easier, cheaper, better than a cap bank ! Now I feel kinda stupid because I started a thread called "Controller tuning or mods for more volt or amps" and this shunt mod was discussed a lot and even you yourself replied to it :lol: Why the hell did I not think of it myself ...
  18. Sparfuchs

    reduce voltage drop between battery and controller

    Thanks a lot for your explanation, but I'm afraid I don't have enough basic knowledge to really get it in detail. But I guess I don't have to because your "shunt mod" hint might solve my problem. I used 8 AWG wires with over all about 16 inch length. So I also doubt that there is a problem with...
  19. Sparfuchs

    reduce voltage drop between battery and controller

    Well, for me all the voltage means from 4,16v down to 2,5v. So almost 30v from fully charged to lack voltage. Means at 160 amps still 10v left before my lack voltage :) Of course down to 3,17v would be better for cycle life, but I don't think going closer to 2,5 for a few sec. from time to time...
  20. Sparfuchs

    reduce voltage drop between battery and controller

    I'm pretty sure it is what it does. But I'm also pretty sure that my cells are not even close to their limits with a discharge of 20amps for just a few milliseconds! and no change in temperature at all. In tests from others with 45amp "continuous" per cell the temp. got up to 80 degrees and...
  21. Sparfuchs

    reduce voltage drop between battery and controller

    Here is a picture of my connections and the 8awg wire I used. As the voltage drop isn't really that unexpected to me, I l'd just assume everything is fine. But if you still think it's useful to do do more tests I will. So my available measuring instruments are a multimeter and my cycle analyst...
  22. Sparfuchs

    reduce voltage drop between battery and controller

    The sabvototon has six 100V 680 uf capacitors and looks a bit like that already acts as a cap. bank or what else what they do ? I'll try to check with the volt value with the app (while driving) to see if the sabvoton even notices the voltage drop. I would guess it makes more sense for the...
  23. Sparfuchs

    reduce voltage drop between battery and controller

    Nope, it's not about saving a couple of dollars and even if I'd build a new pack I'd get more range. And as I won't throw away the current pack and could use it for other projects it won't be any financial loss at all. But it's a bike with a self designed steel construction for a motocross 2...
  24. Sparfuchs

    reduce voltage drop between battery and controller

    I just noted the resting voltage, then reseted the cycle analyst v3 trip data, then hit full throttle, and noted the Vmin and Amax from the c.a. memory. Then repeated this procedure many times to get a average. But the Vmin and Amax values were so short pulses that I can't remember that I've...
  25. Sparfuchs

    reduce voltage drop between battery and controller

    Jap, according to datasheet 35amps continuous and 45 amps with temp cut off, according to independent testers like "mooch" it's 25 continuous and 35 with temp cut. Yes I do, it's a 300amp Ant BMS and works fine. Yes, I did.. so I know for sure that all the components are connected with the...
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