Yet another battery saftey question

Discussion in 'Electronic Cigarette Safety' started by daddy crow, Aug 7, 2017.

  1. daddy crow

    daddy crow New Member

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    Been doing research as much as I can but I'm hoping someone can help me figure this out.
    I'm currently using a smok alien 220 mod with 2 efest 2600mah 40a 3.7v batteries ( not great I know, looking g to change to something better soon)
    Anyways the batteries say the max constant output is 25a and I've noticed when vaping at 70wats the screen says the amps are around 21 - 22 amps.
    So my question is if I vape it any higher am I going to be vaping safely or am I going to be putting a bunch of stress on my batteries.
    Sorry if I sound dumb but I would like to understand this better.
    Any jelp is greatly appreciated

    Sent from my SM-G900T1 using Tapatalk
     
  2. AndriaD

    AndriaD Shine on, you crazy... VU Donator Diamond Contributor Member For 3 Years ECF Refugee

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    I think you're already putting more stress on those batteries than is likely safe -- efests are re-wraps of batteries that for whatever reason, were judged inadequate or unsatisfactory by whoever made them, and thus aren't labelled with that maker's name. It may say that their CDR is 25A, but I'm timothy leary's brother about that (ReallyReally Leary (sic) !); I'd guess they're really only about 10-20 amps.

    To truly be safe, I'd say stick with Samsung, LG, or Sony, *FROM A REPUTABLE SELLER* such as liionwholesale.com or illumn.com -- both of those sell quality batteries from quality makers which are not counterfeits, for excellent prices, and both also throw in a free battery box with every pair purchased.

    Andria
     
  3. The Cromwell

    The Cromwell VU Donator Diamond Contributor Member For 1 Year

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    You are prolly ok. The batteries are likely 20A CDR batteries.
    the 21 amps you are seeing is the current output to the atomizer/tank.

    Each battery is likely supplying about 12 amps or a bit more depending on the efficiency of the converter circuitry in the MOD.

    A general rule of thumb for 20A CDR batteries is 75 watts max per battery.
    So in theory you should be ok up to 150 watts.

    But then again I am assuming that those batteries are at least 20 AMP CDR. It is possible they are really 25A CDR batteries.
     
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  4. David Wolf

    David Wolf Bronze Contributor ECF Refugee

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    If those are the purple Efest 2600maH "40A" batteries, Mooch tested them and says that they are only re-wrapped 20 Amp batteries:
    https://www.facebook.com/1636157550....1073741828.1636157550007158/1674040996218813
    The formula I recommend (conservative engineer here) for calculating the battery current is:
    I=Power/Vmin-cutoff/efficiency, where Vmin-cutoff is your mods minimum cuttoff voltage (typically around 3.2V, but for your Alien 220, djlsbVapes tested it and found it to be around 2.8V per cell (very low!):
    http://www.liquidjuicevaping.com/d2884c.video
    For efficiency I use 0.85%, and with your two batteries in series, the minimum voltage SHOULD be 3.2V x 2 = 6.4V, and
    I = 75W/6.4V/0.85=13.8 Amps draw from your two batteries in series.
    If you use the 2.8V value as the cutoff per djlsbVapes testing however, you get 15.8 Amps.

    I don't really use a rule of thumb, I use the calculations above. If I had to pick a maximum power for a 20A battery as a rule of thumb, it would be 50W, which results in (for a single batter mod):
    I=50W/3.2V cutoff/0.85 efficiency = 18.4 Amps, which keeps me under the 20 Amp continuous rating where I would rather be :D
    So for a 2 battery series mod, 100 W max will keep you at 18.4 Amps.as long as you don't go below 3.2V battery voltage per cell.
     
    Last edited: Aug 7, 2017
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  5. daddy crow

    daddy crow New Member

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    Thank you that is extremely helpful.
    Now I just need to work out how to figure out the variables to plug in and learn the calculations.

    Sent from my SM-G900T1 using Tapatalk
     
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