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  1. BatteryMooch

    Tabless design cylindrical cells tests

    There was a huge amount of press on the JP40 and a big trade show release of that cell. I haven’t seen nearly as much for the JP30 (and only the JP40 is on their web site) but the first cell in a new line always seems to get the most attention.
  2. BatteryMooch

    Tabless design cylindrical cells tests

    All of the “tabless” 21700’s have a single cathode tab though (from the current collector plate to the top contact) and hotspotting should still be a potential issue IMO. The anodes are tabless except for the 45D. Though I enjoy the discussions here one day it would nice to not be limited to...
  3. BatteryMooch

    Tabless design cylindrical cells tests

    Hot spotting and electrolyte degradation (creating gas and byproducts) is potentially an issue as I had two AM04’s pop their CID’s when run at a high current level (within rating) up to the datasheet’s max external temp spec.
  4. BatteryMooch

    Tabless design cylindrical cells tests

    Thanks for the info! I’m surprised the temp difference was that large…interesting! Great to hear that fast charging didn’t affect the results. I’ll switch to 5A charge/8A discharge (still 2.50V cutoff) then as I’d like to speed up the cycling. This will mean that I am using the same charge...
  5. BatteryMooch

    Tabless design cylindrical cells tests

    I just had a client cancel some testing so I thought this would be a good time to try to help figure out why our EVE 40PL cycling results were so different. Our low voltage cutoffs and charge rates were different (leading to different actual voltage cutoffs) but the IR of this cell is so low I’m...
  6. BatteryMooch

    LG INR21700-M58T?

    Just a separate note…it was 5.4Ah delivered at a 5A discharge rate where there’s much more voltage sag than the typical 0.2C rate used by energy cell manufacturers for their cells and often down to 2.5V-2.75V, depending on the cell. Vapcell said to treat these ”normally” so my capacity tests...
  7. BatteryMooch

    LG INR21700-M58T?

    My capacity tests are to 2.5V (or datasheet low voltage cutoff) but my performance discharges (which are graphed) are down to 2.8V since almost no one runs lower than that in their application and it prevents a lot of confusion.
  8. BatteryMooch

    Tabless design cylindrical cells tests

    Excellent! Has to be some reason to avoid the weld areas though or otherwise the manufacturers wouldn’t have these warnings. Hopefully she/he can give you some great info! Do you also have access to an applications or test engineer? They’d be the ones who test production cells and/or get the...
  9. BatteryMooch

    Tabless design cylindrical cells tests

    Hmm…interesting possibility. A battle between lithium plating and high temps (from high C rate) vs DoD damage. I’ll wait for your results of the 5C to 2.50V cycling and if it looks like it might be useful I can run 100 of the same cycles to compare results against. Thank you for doing all this...
  10. BatteryMooch

    Tabless design cylindrical cells tests

    My apologies for the delayed response. I’ve seen spot-welding location issues discussed in research papers (li-ion aging mechanisms) but I don’t remember which or have links. Beyond spot-welding’s degradation of the electrolyte (and deposition onto the SEI of the byproducts, increasing IR) the...
  11. BatteryMooch

    Tabless design cylindrical cells tests

    Nope…the abusive cycle life testing uses a 2.50V cutoff, mentioned in my post: Tabless design cylindrical cells tests. After 250 abusive cycles I’m at a run time loss of 7.5%. The “E-Scores” (delivered Wh) for the conventional performance tests are measured at 3.2V though. Ampace recommends...
  12. BatteryMooch

    Tabless design cylindrical cells tests

    More testing is ongoing but here’s some info on the cycle life of EVE 40PL cells available now. After 200 abusive cycles*** the run time/capacity of the cell only dropped 5.6%. Significantly better than the very disappointing cycle life of the (presumably) pre-production cell(s) @Pajda tested...
  13. BatteryMooch

    Is the Molicel P50B “tabless”? I tore one down to find out…

    Cost and paperwork I suspect. Nkon and companies on AliExpress/Alibaba won’t ship cells to me here in NYC.
  14. BatteryMooch

    Is the Molicel P50B “tabless”? I tore one down to find out…

    Happy to test them…crazy hard to get them here in the US. I’ll put in the time though if anyone sends a pair of the New Hotness they want tested to me here in NYC.
  15. BatteryMooch

    Is the Molicel P50B “tabless”? I tore one down to find out…

    Moli sent the ones I have. IIRC, www.nkon.nl was supposed to be getting some soon (presumably samples) and Vapcell too (check Alibaba/AliExpress).
  16. BatteryMooch

    Is the Molicel P50B “tabless”? I tore one down to find out…

    TL;DR…no. This cell uses the same tab design as other round li-ion cells, but has more tabs to reduce internal resistance and increase current handling. Images: Some observations and comments: NEVER TAKE APART A LI-ION CELL! Even a tiny spark can ignite the flammable electrolyte that is...
  17. BatteryMooch

    Any EVE 40PL available for purchase? Would love to test these. FOUND!

    Hello all, I have found a source for samples (which I can‘t name yet) and hope to be testing soon.
  18. BatteryMooch

    Any EVE 40PL available for purchase? Would love to test these. FOUND!

    Thanks! 🙂
  19. BatteryMooch

    Any EVE 40PL available for purchase? Would love to test these. FOUND!

    Contacting EVE was my next step. 🙂 Contacting Queenbattery is a great idea! Thanks!
  20. BatteryMooch

    Any EVE 40PL available for purchase? Would love to test these. FOUND!

    I have been unable to find any of these so far. Anyone have two they would sell or know of a source? Thank you! Samples located and on the way!
  21. BatteryMooch

    Bench Test Results: Molicel P45B - 50A 4500mAh 21700…an extraordinary cell!

    It did well… Molicel P45B Cold Cell Discharge Test - Cell date code 2L830. - Ambient temperature = 23.6°C. - Cell charged to 4.20V at 1A down to 100mA cutoff. - 9.5 hours in a freezer, temp ranged from -15.2°C to -15.6°C (over 6hr period) after cell dropped to freezer temp. - Cell removed from...
  22. BatteryMooch

    Bench Test Results: Molicel P45B - 50A 4500mAh 21700…an extraordinary cell!

    Whoa…nice gear! Don’t know when I’ll be out there but will definitely contact you if I am.
  23. BatteryMooch

    Bench Test Results: Molicel P45B - 50A 4500mAh 21700…an extraordinary cell!

    LOL…having so many problems staying logged in and when posting! I’m torture cycle life testing a 40T3 for my patrons now but will try to do that freezer test later this week. To confirm…full charge to 4.20V, soak in freezer at least overnight, and then 7.5A down to 3.2V plotting run time vs...
  24. BatteryMooch

    Bench Test Results: Molicel P45B - 50A 4500mAh 21700…an extraordinary cell!

    Hello! Verrry long time no see. :P Thank you for your kind words!
  25. BatteryMooch

    Bench Test Results: Molicel P45B - 50A 4500mAh 21700…an extraordinary cell!

    For some tests, a pair of BK Precision 8601 Electronic Loads and the temperature sensing described below. For these tests…calibrated West Mountain Radio CBA Pro IV Battery Analyzer modified for lower voltage drops and better cooling (to reduce thermal drift) with custom high-current mount and...
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