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  1. M

    Amount of cells? many or few

    Okay! so it is just the charger itself (combined with actual heating in the batteries) that makes the batteries feel warm in the charger?
  2. M

    Amount of cells? many or few

    Okay i am confused... when i charged the batteries and tested them in the lii-500 all batteries are "warm", i mean they are not room temperature but they get warmer (at max settings) even the samsung got warm i took 3 of the worse FST cells in a 3S config, i am powering a 10W (12V) led lamp...
  3. M

    Amount of cells? many or few

    Okay, i shall fully charge them and think some more and test.
  4. M

    Amount of cells? many or few

    Maybe. i think i might re-evaluate some things. maybe i should start out with a smaller pack, continue testing the FST cells (those 700cells cost less than the samsung and panasonic together). at 700 cells 1A output is going to be 2.6kw nominal. Just going to mix the samsung and panasonic, at...
  5. M

    Amount of cells? many or few

    yeah, i am sorry. yes it is pretty spread out mainly you and me typing I have: 100x Samsung 26J 5.2A 100x Panasonic NCR18650 PF 10A 700x FST 2Ah under testing I am not so sure about the tested cells i got thou. i did read somewhere that u should fully charge your cells, let them wait for some...
  6. M

    Amount of cells? many or few

    Flippy, have you not read the thread at all? I am testing them all before i am using them... So far i've tested 75 cells, they average 2016mah. the lii-500 say they have the same IR as my samsung inr 26j which are rated at 5.2A nominal output. If they are used before they went into the scooter...
  7. M

    Amount of cells? many or few

    FST 18650-2000mAh CAP: 2000mAh VOL 3.6V/4.2V NB21017 084448 This is what the cell say did look up the datasheet some time ago, don't remember it by heart. what i find on the internet are blue cells, mine are teal. should be good for 2kw at 429 cells. or should i increase it to get down the...
  8. M

    Amount of cells? many or few

    Thanks for the response flippy. i am aware of the risk, that's why i am aiming for lower current per cells. the battery packs comes from (scooters?) whatever u call them in english A pictures sometimes say more than a 1000 words. anyways u rent them in the city and just park them anywhere, and...
  9. M

    Amount of cells? many or few

    I am actually entering them all into excel :P Since i am going to test 700 cells i will probably have a lot of good and worse ones. so far i've tested a bit, i have already discarded the ones that are under 1800 into a separate holder. but maybe they are not that bad after all. it would be such...
  10. M

    Amount of cells? many or few

    Thank u flippy! i am checking IR on all cells, they are about the same, the only that differs are mah. The cells i am testing are rated at 2000mah (at 1C), most cells have tested at 1850-2100mah, but a few have tested at around 1600mah, so less or more 80%. but if i get this correctly, i should...
  11. M

    Amount of cells? many or few

    hi flippy! See it more as a general question, if u read the whole thread it's basically about battery packs and how to alter the parameters of the pack itself, what will change if you do this and that. For example you got 5 cells of samsung 2200mah, 2 are brand new, and 3 are older and cyceled...
  12. M

    Amount of cells? many or few

    forgive me if this sounds stupid, but what if i build a 13S pack with some units with 33 cells, some with 31 and some with 35P, as long as they are the same cell type and if i balance each unit in regards to mah, it would be rather okay then?
  13. M

    Amount of cells? many or few

    wow, just 1mm is enough? i measured it and it is 1.8mm in between each cells. i thought it was a very thight cell holder (a lot tigther than the square version). quick question, this might sound very stupid okay, but hear me out. if i got 2 cells at 2250mah, they make 4500mah together, would 3...
  14. M

    Amount of cells? many or few

    unfortunately i can't print them, i am locked to the cell holders in picture (50cells) many holders of 10 cells (arrangement 3-4-3), don't have a 3d printer. i will see what i can do, gonna try some setups in the program later
  15. M

    Battery capacity tester (ZB2L3)

    I got recommendation to buy this ZB2L3 or similar as a cheaper alternative to test capacity on batteries. would provide a larger range of amperes and more abilities to choose cut off voltage etc. Have anyone tried them? i have some batteries that are hard to put in the liitokala lii- charger i...
  16. M

    Electric motor - what voltage?

    So i can pick any voltage range i want, and there is not really a difference between at 48V, 60V or 72V motor as long as they are having the same output power :| But if i my thinking is right, higher voltage and lower amp on the output side will mean more cells in series, and therefore less amp...
  17. M

    Amount of cells? many or few

    personal like button then :P This forum really got me interested in ev related projects. mostly DIY stuffs. going to bid on some autions tomorrow (today) and see if i can get some LiFePO cells, 56 cells at 10ah, but we'll see how it goes, if they get to pricy i'll let them go. was thinking if i...
  18. M

    Electric motor - what voltage?

    Well i am hoping i am putting this thread corretly now. i got a lot of batteries over that i wanna do something fun with. got an old bike at home with a broken engine etc, been sitting in my garage for 10+ years. (it is a derbi gpr nude 50cc). I might want to try and put an electric motor on it...
  19. M

    Amount of cells? many or few

    Then would it make sense to spread the pack a bit apart, even thou it will consume some more nicklestrip to connect it to allow for more air to get between the battery cells, or is this dense solution still alright in general? at 2kw and 13s33p it is 1,26A per cell, so an average of about 0,6C...
  20. M

    Amount of cells? many or few

    So at 13s33p. 429 cells at 1A is 429x3.7 ~1.6kw. So if i want 1.6kw, it will be about 0.35W per cell, 0.35*429 which is about 150watt of heat. and if we stress the pack at 2kw or even the maximal of the inverter (2.5kw) we are somewhere in the range 200-250watt of heat development. I read the...
  21. M

    Amount of cells? many or few

    Alright, i guess that sounds fair. the cells i am testing is in the range 25-35 miliohms (according to liitokala). I am not sure what that actually stands for in regards to heat build up. only reference i really have is that some highpower cells might have around 10miliohms IR, and some cheap...
  22. M

    Amount of cells? many or few

    Fatty, i got a theoretical question about the first layout. they are packed very dense compared to the normal square brackets u can buy. i am thinking about heat and cooling. if i will use the pack at somewhere around 0.5-1C discharge i am expecting some heat production, each cell are made to...
  23. M

    Amount of cells? many or few

    yeah, it is my first build, i am also thinking about going the more simple pack to begin with. it felt like a pretty solid arrangement at first glance, when i have the batteries tested and all set up it's not that expensive to pull it apart and get new nickle strips and rebuild it to something...
  24. M

    Amount of cells? many or few

    Another idea of a 3x3 with an empty core. in total "just 25p" so for a 13S it's 325 cells, and a 14s will be 350 cells. in this pack there will need to be insulation between each pack stacked on top of eachother. but the series connection will be basically nickle plates "U" shaped/folded to...
  25. M

    Amount of cells? many or few

    So. am i building this pack right? 13s33p. red "dots" are battery + end and plain silver is - end. Red and Blue cubes represent + and - at the battery pack
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