Results 1 to 8 of 8
Like Tree6Likes
  • 1 Post By Altered1
  • 2 Post By coopz
  • 1 Post By Spyro
  • 1 Post By Spyro
  • 1 Post By Yeug

Thread: Quick clarification on battery safety

  1. #1
    Senior Member
    Join Date
    Mar 2014
    Location
    Melbourne
    Posts
    253

    Quick clarification on battery safety

    Hey guys, quick one
    I'm using AW IMR 18650's (the 2000 mah type) and I'm trying to figure out what is the minimum resistance I can safely use on a non-regulated device.
    I understand that it's not a good idea to ride your battery's limit for a number of reasons, so I need to know what it is so I can stay in safe distance from it when building my coils.

    So first things first, what is my battery's true C rating.
    Here it says 5C, which seems to agree with this that says this battery has a max continuous discharge of 10Amps.
    Max Amp draw= Mah/1000 * C rating => 10AMP = 2000/1000 *5

    Cool.
    So if I feed that 10Amps and the 3.7 V nominal voltage of this battery into an Ohm's law calculator I get a resistance of 0.37, which should be the absolute bottom of safe usage of my battery (when in good condition, relatively new etc)

    Does this sound about right?
    DONT DRIP AND DRIVE!




  2. #2
    AVF Regular
    Join Date
    Oct 2013
    Location
    Melbourne
    Posts
    3,690
    sounds like you've got a good grasp of ohms law. don't exceed the max amp draw, don't run your batteries down too low.

    I don't go for sub ohm coils, so hopefully one of the other guys will post here. I assume you've read the battery safety thread.
    Spyro likes this.




    Gaffer Tape is like The Force - it has a light side, a dark side, and it holds the universe together

    Without specific approval, No one has permission to quote me outside of AVF

  3. #3
    AVF Regular
    Join Date
    Mar 2014
    Location
    Adelaide SA
    Posts
    1,111
    A good question that I don't know the answer to but I'd like to know myself so hence the purpose of this post.

    Having said that I always lean to the safe side and I personally wouldn't go lower than .8 Ohms with a battery that has a max continuous discharge of 10Amps.
    Any lower than that and even if everything works OK the whole things gets hot really quickly and the battery goes flat in no time.
    Peter

    My last cigarette... 3rd April 2014

  4. #4
    Senior Member
    Join Date
    Aug 2013
    Location
    Perth
    Posts
    2,474
    Quote Originally Posted by Spyro View Post
    Hey guys, quick one
    I'm using AW IMR 18650's (the 2000 mah type) and I'm trying to figure out what is the minimum resistance I can safely use on a non-regulated device.
    I understand that it's not a good idea to ride your battery's limit for a number of reasons, so I need to know what it is so I can stay in safe distance from it when building my coils.

    So first things first, what is my battery's true C rating.
    Here it says 5C, which seems to agree with this that says this battery has a max continuous discharge of 10Amps.
    Max Amp draw= Mah/1000 * C rating => 10AMP = 2000/1000 *5

    Cool.
    So if I feed that 10Amps and the 3.7 V nominal voltage of this battery into an Ohm's law calculator I get a resistance of 0.37, which should be the absolute bottom of safe usage of my battery (when in good condition, relatively new etc)

    Does this sound about right?
    Work off 4.2v, because that's what the batteries are when fully charged, and by 3.6v they are ready to be recharged again anyway...

    e: Also, when working off the C rating, it's only safe to assume that is the case with new-ish batteries, not ones that have been damaged by a crap charger (over current or volt), or ones that the user has damaged by over discharging them.
    Last edited by coopz; 20-04-14 at 11:37 PM.
    sc_rufctr and Spyro like this.

  5. #5
    Senior Member
    Join Date
    Mar 2014
    Location
    Melbourne
    Posts
    253
    excellent thanks

    apart from safety, any other reason for dumping AW and going for a Sony, Orbtronic etc that have amp limits of 30A or higher?
    Is it just for going ultra-low ohm, or is there more to it?
    sc_rufctr likes this.
    DONT DRIP AND DRIVE!




  6. #6
    Senior Member
    Join Date
    Mar 2014
    Location
    Melbourne
    Posts
    253
    Quote Originally Posted by sc_rufctr View Post
    A good question that I don't know the answer to but I'd like to know myself so hence the purpose of this post.

    Having said that I always lean to the safe side and I personally wouldn't go lower than .8 Ohms with a battery that has a max continuous discharge of 10Amps.
    Any lower than that and even if everything works OK the whole things gets hot really quickly and the battery goes flat in no time.
    same, I don't really want to go too low. However I'm still a bit heavy-handed in my builds, and when some of them end up too low I still want to have a vape... and I want to make sure I can do it without anything melting in my hands
    sc_rufctr likes this.
    DONT DRIP AND DRIVE!




  7. #7
    AVF Regular
    Join Date
    Oct 2013
    Location
    Melbourne
    Posts
    3,690
    Quote Originally Posted by Spyro View Post
    same, I don't really want to go too low. However I'm still a bit heavy-handed in my builds, and when some of them end up too low I still want to have a vape... and I want to make sure I can do it without anything melting in my hands
    if in doubt, put another wrap on that coil ?




    Gaffer Tape is like The Force - it has a light side, a dark side, and it holds the universe together

    Without specific approval, No one has permission to quote me outside of AVF

  8. #8
    AVF Regular
    Join Date
    Feb 2014
    Location
    Melbourne
    Posts
    390
    Quote Originally Posted by Spyro View Post
    excellent thanks

    apart from safety, any other reason for dumping AW and going for a Sony, Orbtronic etc that have amp limits of 30A or higher?
    Is it just for going ultra-low ohm, or is there more to it?
    Well for the most part it is for safety. It would be better to get 30amp limit batteries, better to be safe than sorry as they say.

    Another reason is if you vv/vw or specifically DNA chip mods, the 30amp batteries allow you to use it on high wattages.

    Hope this helps
    Spyro likes this.

 

 

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Powered by vBulletin® Version 4.2.4
Copyright © 2019 vBulletin Solutions, Inc. All rights reserved.
Search Engine Friendly URLs by vBSEO 3.6.0
All times are GMT +11. The time now is 02:21 AM.