Whats is the 'Maximum Vaping Amps' in Mooch's safety rating tables?

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Mooch

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    In that context, how low is a dead short?.. Is it achievable by just building too low? Can 0.05 ohms be considered a dead short? Or is it so low that it can not be done with a coil..

    There are shorts and there are shorts.
    Technically, any connection without a load being present is a short. But this could be through wiring, connections, electrical components, etc., and could actually result in not very much current flowing.

    A "direct" short would be something more like a battery with a damaged wrap and missing insulator being put in a pocket with change or keys. The current that flows could be 10x higher that way.

    A rough estimation of what a battery might consider to be a short circuit is any load lower in resistance than the battery's own internal resistance. That's about 20mOhms in a good high-performance battery, up to about 100mOhms in the ultra high capacity batteries.

    Because of the other resistances involved it's very hard to bring a battery into thermal runaway with too low of a coil resistance. An atty with a spring-loaded 510 pin on a hybrid top cap mech could bring a battery into runaway in less than a second though.

    So, to answer your questions, it depends. :)
     

    Noahian

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    Sep 9, 2012
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    There are shorts and there are shorts.
    Technically, any connection without a load being present is a short. But this could be through wiring, connections, electrical components, etc., and could actually result in not very much current flowing.

    A "direct" short would be something more like a battery with a damaged wrap and missing insulator being put in a pocket with change or keys. The current that flows could be 10x higher that way.

    A rough estimation of what a battery might consider to be a short circuit is any load lower in resistance than the battery's own internal resistance. That's about 20mOhms in a good high-performance battery, up to about 100mOhms in the ultra high capacity batteries.

    Because of the other resistances involved it's very hard to bring a battery into thermal runaway with too low of a coil resistance. An atty with a spring-loaded 510 pin on a hybrid top cap mech could bring a battery into runaway in less than a second though.

    So, to answer your questions, it depends. :)

    Oh, Ok.. So practically lower than internal resistance is a short.. And its not very probable at least with a regulated mod.. thanks a lot...
     

    Imfallen_Angel

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    Oh, Ok.. So practically lower than internal resistance is a short.. And its not very probable at least with a regulated mod.. thanks a lot...

    Unless the wrap rips, the insulation ring bends as you're putting the battery in the mod.. and this happens on the battery connection pin all in one swift motion under 1 second.

    Then battery sparks violently, vents and the mod's board fries.

    In other word, be gentle with you insert your batteries and double check your wraps and don't take chances if there's any sort of rips, especially on the positive side.
     

    ScRue58

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    Apr 21, 2017
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    Great information! But to be sure...Am I playing with fire if I fire my SMOK TFV12-X4 coil at 130 watts (says best between 90-130 watts)-4.56 volts, reading at .16 ohms on my RS200S with three Sony VTC4 batteries from IMR? The screen says 26.6 amps when I pulse for 3-4 seconds. Mooch's CDR for VTC4s is 22A. This is what I've been doing, and it's a very satisfying vape for me. Have I been playing with a grenade?

    What if I put the T12 coil (.12 ohms, recommended 130-200 watts, max 350) in with same setup as above (RX200S with three VTC4s)? Can I actually safely PULSE it to 200 watts, 3-4 seconds? Calculates to 40.82 amps on ohm calc! Haven't tried that coil yet, but it came in the box.

    Any ill effects as capacity drops (ie. batteries at 50% or batteries getting old)?

    What about the above setups with three new EFest metallic purple 3000mah bats, I believe rated at 20A CDR by Mooch?

    I do a quick inspect of battery wraps each time I take them in and out of something (NiteCore D4 charger and mods).

    Thanks for any insight.
     

    Mooch

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    Great information! But to be sure...Am I playing with fire if I fire my SMOK TFV12-X4 coil at 130 watts (says best between 90-130 watts)-4.56 volts, reading at .16 ohms on my RS200S with three Sony VTC4 batteries from IMR? The screen says 26.6 amps when I pulse for 3-4 seconds. Mooch's CDR for VTC4s is 22A. This is what I've been doing, and it's a very satisfying vape for me. Have I been playing with a grenade?

    What if I put the T12 coil (.12 ohms, recommended 130-200 watts, max 350) in with same setup as above (RX200S with three VTC4s)? Can I actually safely PULSE it to 200 watts, 3-4 seconds? Calculates to 40.82 amps on ohm calc! Haven't tried that coil yet, but it came in the box.

    Any ill effects as capacity drops (ie. batteries at 50% or batteries getting old)?

    What about the above setups with three new EFest metallic purple 3000mah bats, I believe rated at 20A CDR by Mooch?

    I do a quick inspect of battery wraps each time I take them in and out of something (NiteCore D4 charger and mods).

    Thanks for any insight.

    That screen shows you the current from the regulator to the coils, not the current from the batteries to the regulator. In a multi-battery mod the battery current is a lot lower than the coil current.

    Check the index for my blog (link in my signature) for the link about calculating battery current for a regulated mod. Then grab my 18650 ratings table to see how hard you can run the batteries you mentioned.
     

    Topwater Elvis

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    The amp displayed on the screen is output - from 'chip' to delivery device.
    The input - from batteries to 'chip' is what to be aware of.
    ---> Calculating battery current draw for a regulated mod | E-Cigarette Forum
    https://www.e-cigarette-forum.com/f...attery-current-draw-for-a-regulated-mod.7532/
    Just me, I don't use nor recommend any efest batteries.
    All cells we call re wraps can & frequently do change what cell is used beneath the wrap. In my mind that makes them untrustworthy, I don't support any business that uses false / misleading / inflated numbers as marketing hype.
     

    ScRue58

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    Apr 21, 2017
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    Exactly what I was looking for! It appears that at 200w on the RX200 you would want at least 24A (rounded up) capable batteries, figuring in 3.0 cutoff voltage per bat and 5% margin for regulator inefficiency. Am I correct in my thinking here?

    So...back to original post thoughts, do I base my decision on CDR or MVA? VTC4s are 23A CDR and 30A MVA. Efest metallic purple are 20A CDR and 25A MVA (assuming they are genuine, which I guess one cannot).
     

    Topwater Elvis

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    You educate yourself on battery saftey & selection, then you chose cells based on that info in combination with your own personal comfort levels / saftey parameters.

    To more directly answer your question, you determine which to use (CDR vs MVA) that depends on which you feel most comfortable using.
    You gotta ask yourself, what am I going to gain, what does this gain cost me in saftey, battery life & peace of mind, is this gain something I need or even want.

    I never exceed or recommend exceeding the CDR of any cell, usually I stay at least 20% usually 50% under/below the CDR.

    Used in a regulated power device, my personal battery comfort level which some folks feel is conservative is:
    20a CDR ~ 50w - 60w per cell.
    25a CDR ~ 60w - 75w per cell.
    30a CDR ~ 75w - 90w per cell.
     
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    ScRue58

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    Apr 21, 2017
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    T. Elvis--By your table, you're indicating that you'd be at the limit your personal comfort running three 23A CDR VTC4s at 202.5 watts (figured 67.5w per cell) in a regulated mod? That seems just about running each bat at CDR, but not really below it, when at the max range you indicated you run conservatively.

    So bottom line, gauging by Mooch and Elvis' information and personal preferences (not advice ), I could feel fairly comfortable running my VTC4s in my three battery RX200S at 200 watts, not higher. And should probably save my EFest batts for a lower range due to possibility they've been re-wrapped.

    Thank you guys so much for the information! Certainly helps!
     

    Topwater Elvis

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    It is very rare that I even equal the lower W per cell in my previous post & never recommend exceeding the higher W.

    I don't use vtc4's & I don't consider them 23a CDR cells, so I wouldn't exceed 150w with 3.
    If you chose to exceed that then I would say, you can use & abuse your cells any way you see fit, I wouldn't exceed 180w on 3 for any reason.

    Seems the fad of horrendously inefficient setups pushing everything to extremes in vaping has made it almost impossible for me to participate in semi reasonable battery saftey discussions.
    No one wants to hear, saftey first, no reason to push limits, there are risks when using these cells in the manner we do.
     
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    ScRue58

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    Dont think I would want to vape that high, just want to know my max limits without pushing it (if that makes sense) should I decide to experiment when trying different coils. I currently am vaping at 130w on the TFV12-X4 (130w/3 cells= 43.3w per cell, 43.3/3.0 cutoff voltage=14.5A, 14.5/.95 inefficiency margin=15.2 amp draw) and thats good for me and well within safe margins for my setup if my figuring is right. I'll not go above 170w (19.88A) on the VTC4s. This is figured using the tables and formula from Mooch. T. Elvis, thank you for your safe recommendations and good conscience.
     
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