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Thread: Honestly speaking, how dangerous are Panasonic NCR18650B or Samsung INR-32A?

  1. #1

    Default Honestly speaking, how dangerous are Panasonic NCR18650B or Samsung INR-32A?

    Hi - being new to candlepower, I come hear with a loaded question -

    I am coming from the EV and electronics forums, and I am sick and tired to hear their horror stories of 18650's exploding like a grenade, and spewing hot chemical gasses in your face, and once a cell catches fire, the rest of the pack blow up like a mini-nuke. None of these are first-hand knowledge, and seems to be perpetuating an urban myth about 18650s.

    How real are these horror stories? All I could find on YouDupe are very old vids regarding the Sony defective 18650s in laptops.

    My applications relate to EVs, and not racing. So the power drain is a very modest 0.3C, and maximum 0.5C, as the packs are huge - 12 kWh or 40 kWh.

    Do we hear of laptops exploding anymore? Or Teslas exploding as they are sitting and parked? No.

    What is the chemistry of these two cells? I assume they have moved away from pure cobalt to NMC or NCA a long time ago?

    What is the consensus here regarding the safety of the top rated Pany, Samsung, and LG 18650 cells? Has anyone a video for top rated cells testing 1- nail penetration or 2- non-puncturing but internal shorting heavy impact?

    Thank you in advance for any opinion or information provided.

  2. #2
    ven's Avatar
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    Default Re: Honestly speaking, how dangerous are Panasonic NCR18650B or Samsung INR-32A?

    18650's are like cars in a way, if you drive within the guide lines, dont push them too far , you will have enjoyment. Ignore basic rules, dont take care of them, expect a poor experience that could end up bad.

    Cell spec is usually 2.5v up to 4.2v(variable depending on manufacturer). Dont over charge and discharge outside these specs. I have maybe 100 18650's, most used and some stored. Yet to have any . I tend to charge to 4.2v, most cells i charge back up very rarely see bellow 3.3v, more around 3.6v on average. As important as good cells(sony/LG/Samsung/panasonic/sanyo) is a good charger(not cheap ebay rubbish). Its always a good idea to have another way of measuring the voltage, multi meter would come near the top of useful tools for this purpose.

    Like with most hobbies/interests, picking the right gear is key to how safe, how fun and how practical/efficient it is. You vape, you get some decent high drain cells, just as you would a high powered flashlight. You want to run your 3s RC car for 15mins, you buy a decent brand battery to suit that use/environment.

    Right now, Samsung 30Q, Sony vtc6 and vtc5a are up there for very good 18650 cells. These are a "hybrid", so a mix of chemistry that may be shown as INR(or IMR). Lots of info on here if you use the search(top right google search box) for more details.

    Read up, ask away and hopefully your mind will be put at rest knowing that most horror stories are caused by ignorance........


  3. #3

    Default Re: Honestly speaking, how dangerous are Panasonic NCR18650B or Samsung INR-32A?

    Hi ven - and thank you for your welcome and reply.

    I am building a 12 kWh pack. So I am taking the following standard precautions. The pack consists of 1040 cells (currently Pany 3.4Ah) and is made of 8 modules, each 10 cells parallel and 13 serial (for 48V). The modules are wired in serial. In other words, the pack is 8s1p13s10p. This gives me nominal 374V at 34 Ah. Continuous current drain is 1.7A per cell and max is 4.5A per cell. So the discharges are not excessive. I am taking the following precaustions -

    Each cell has its own little fuse that will blow up at 10A.
    Each module has a cell balancer for 13 sells in serial and a cell protector. The protector will trigger and cutoff the module if charging voltage exceeds 4.2V per any cell, or charging current supplied is over 0.5C, or if discharge current exceeds 5A, or if discharge voltage is below 3V. Also it protects the pack against an external short. Also excessive thermal detection and cutoff.

    Then there is the charger which is CCCV, and will make sure that the voltage never exceeds 4.2Vx13 = 54.6V. The balancer assure that all 13 cells reach 4.2V, and if any exceeds that, it will bypass the cell. If it continues to exceed that, it will cutoff the charging.

    So there is triple protection. First the charger, then the protector board, and then the little fuse. Some call the board a PCM or PCB or BMS.

    I am not concerned about impacts or accidents happening to the EV (one project is a boat), and my concern is not about charging or discharging either.

    My main concern is spontaneous internal short, thermal runaway, and stuff that can happen internally to the battery that I have no control on. Like the Sony manufacturing problem that blew up lots of laptops.

    What can go wrong spontaneously with a pack of 1000 cells, where charge and discharge are nominal and modest.

  4. #4
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    Default Re: Honestly speaking, how dangerous are Panasonic NCR18650B or Samsung INR-32A?

    Hello Solarsail,

    I will echo... Welcome to CPF.

    Most of the problems with Li-Ion cells happens when they get into unbalance conditions. It appears that you have taken precautions against that.

    IF the cells are high quality the probability of internal shorting is very small. Keep in mind that 1000 cells together in a pack store a lot of energy so caution is needed. I don't worry about the first couple of years of use, but after that things may start to break down and pose more risk. However, keeping track of the health of the cells should help you avoid any problems.

    Tom
    Behind every Great man there's always a woman rolling her eyes...

    Most batteries don't die - they are tortured to near death, then murdered...

  5. #5

    Default Re: Honestly speaking, how dangerous are Panasonic NCR18650B or Samsung INR-32A?

    Thank you Silver fox.

    "Behind every Great man there's always a woman rolling her eyes..." +10

    I wonder if there is a link to a non-puncturing impact test or penetration test report or video for any of these brand name high capacity (3000+ mAh) cells?

  6. #6

    Default Re: Honestly speaking, how dangerous are Panasonic NCR18650B or Samsung INR-32A?

    Read a few threads here on vapers having a cell go off in a metal tube near thier face. There is also a particular sticky about a flashlight that sent bits across the street breaking a window, stripping the concreted pebbles for a foot diameter where it blew up, and breaking his sliding door and bending its frame. This was years ago likely caused by imbalanced cells but still applies today. Any very rapid gas expansion in something like a sealed water resistant tube(flashlight) is bad. Make sure you have adequate venting in your power pack so pressure can release and heat cannot built up that might send a cell into runaway .

  7. #7
    ven's Avatar
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    Default Re: Honestly speaking, how dangerous are Panasonic NCR18650B or Samsung INR-32A?

    Thats some serious power, iirc overclocker on here has done similar packs and knows his stuff(for a battery powered bike).

    As said, all those cells and balancing is very important. My comments were for general use............this is a different ball game. Good luck with your project

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