Lowest and safest ohm to vape on 2 3.7v battery question

[DiscoPotato]

Hi guys, back again with another question.


If I am to use 2 pcs of AWT IMR 3.7v 18650 battery with my wooden box mod, what is the LOWEST and SAFEST resistance that I can go?


I'm currently using a K100 mechanical mod with an Efest 3.7 battery and I normally keep my attys resistance at 1.8 to 1.9 ohm as per indicated on the vaping Power chart that I found on the forum, but It only shows up to 1.2 ohms...


Can I go lower than 1.2 ohms if my wooden box mod would be running on 2 3.7v IMR batteries?


I'm not aiming to vape on the lowest resistance, only wish to know the range that I should look for so I could at least set my coils resistance in between the minimum and maximum amount and be on the safe side as well.

Looking forward to your response. Thank you.

 

[Das Auto]

I may be WAY wrong here, but from what I understand, when you have 2 batteries connected like they are in a mod box, they would be considered to be connected/wired in SERIES, which you add both battery specs together. So you would have 7.4V & 80A at your disposal from you battery's that you have there. Of course there is still voltage drop from your battery's and from the atty itself, ect..

Now, again, i could be completely wrong. And someone please correct me if I am!! But that is my understanding.

Hopefully this is accurate information and hopefully it helps you!!

 

[JeremyR]

They can be series or parallel. I'm assuming parallel in a mech for 4v. Unless your vaping at 8v... You didn't give the battery amp rating. Staying below the battery amp rating would be safe. Assuming 10amps minimum battery rating for imr, keep it below 10amps.. So yes you can go below 1.2 ohms.. Waiting for specific battery specs.

 

[Das Auto]

I think the Battery ratings and type are on the battery themselves which is the 2nd of the pictures he posted...

And with the Series or Parallel connected batteries, how do you know which yours are on a Mod box, much like the op has? One battery "Up" the other battery "down", would that be Series?

 

[edyle]

Hi guys, back again with another question.


If I am to use 2 pcs of AWT IMR 3.7v 18650 battery with my wooden box mod, what is the LOWEST and SAFEST resistance that I can go?


I'm currently using a K100 mechanical mod with an Efest 3.7 battery and I normally keep my attys resistance at 1.8 to 1.9 ohm as per indicated on the Vaping Power chart that I found on the forum, but It only shows up to 1.2 ohms...


Can I go lower than 1.2 ohms if my wooden box mod would be running on 2 3.7v IMR batteries?


I'm not aiming to vape on the lowest resistance, only wish to know the range that I should look for so I could at least set my coils resistance in between the minimum and maximum amount and be on the safe side as well.

Looking forward to your response. Thank you.


View attachment 415310

You need to know the continuous amp rating of your battery and stay within that limit.
Add a 50% margin of safety if you want to stay on the very safe side.

If the continuous amps rating is 20 amp, then for 2 batts in parallel, your amp limit is 40 amps.
Putting in a 50% safety that brings you back down to 20 amps; which means even if one of the batts konks out or just isn't making contact, you are within the limits of the other battery.

volts = amps x ohms
4 = 20 x ohms
0.2 = ohms

So you're looking at 0.2 ohms on a 20 amp battery.

 

[JeremyR]

I would concur with edyle..

Oh didn't notice the battery pictures at all.. Lol, they're so small on mobile.

Well it would depend how they are wired. Easiest way to know after the fact would be the output voltage. 4 or 8. I highly doubt it's in series for a mech which would be 8.. Although some are into high voltage like myself, most use a regulated mod to achieve high voltage.

 

[DiscoPotato]

Thank you for the answers.

I would be using an AWT IMR 18650, 3.7v 2600MAH 40A.
Though base on what I've seen on the forums, this battery might not even be 40A, because I read before that some battery manufacturer tends to exaggerate the capacity of their battery for marketing.

Let me try to post a bigger pictures of them.





And just to check if my understanding is correct, I'm on the SAFE zone as long as I stay above 0.2 resistance while using 2pcs 3.7v batteries? If that is so, I am more likely to set my coils resistance anywhere between 0.6 to 0.9.
And I apologize if I ask a lot, I'd rather prefer to look completely novice than vape on something that would have a tendency to knock my teeth off

But I am very thankful for sharing your expert thoughts on this. I really love this forum.

 

[JeremyR]

No worries, ask any question you have we will be happy to answer.

Your correct the continuous amp limit on those is lower. The 40amp is pulse rated and not to be used in safe practices of daily vaping.

I also have a set of awt batteries I recently picked up for a song. It is speculated that the cells are LG he2. Based on a test of the awt 35 amp it comes out at 20amps continuous. The 40 amp here is either inflated further as a pulse, or it may sustain 25 amps. 20amps is a safe number though.

An imr battery will not explode. It will heat and vent hot gases possibly some flame. If your mod is vented it won't explode from the gas build up. Also you would typically feel the heat well before it vents.

Heat is the enemy. When the battery compartment gets pretty hot you know something is wrong. Typically your highest risk with a built mod when staying in a safe vaping range is, wire contacts loose/ shorting, or a short In the Atty while fire button stuck. These two things can cause a vent.

Staying in A safe range will help prevent any venting if the button sticks with a clean build. Because the battery should handle the load continuously. That's why we don't follow the pulse rating. Otherwise you throw it in a bag and then have a fire.

 

[edyle]

Thank you for the answers.

I would be using an AWT IMR 18650, 3.7v 2600MAH 40A.
Though base on what I've seen on the forums, this battery might not even be 40A, because I read before that some battery manufacturer tends to exaggerate the capacity of their battery for marketing.

Let me try to post a bigger pictures of them.

View attachment 415583

View attachment 415584

And just to check if my understanding is correct, I'm on the SAFE zone as long as I stay above 0.2 resistance while using 2pcs 3.7v batteries? If that is so, I am more likely to set my coils resistance anywhere between 0.6 to 0.9.
And I apologize if I ask a lot, I'd rather prefer to look completely novice than vape on something that would have a tendency to knock my teeth off

But I am very thankful for sharing your expert thoughts on this. I really love this forum.

My definition of 'safe' would be 2 ohms; anything less than 1 ohm, I would consider not in a safe zone; below 0.5 ohm I would describe as unsafe, and below 0.1 ohm I'm wide eyed with flashing red lights and a robot voice going "Danger, Danger, Danger".

Your 0.6 to 0.9 sounds good enough to not be in the uncomfortable range.

But your biggest reminder:
Parallel batts.

I used to be wondering why makers of regulated mods didn't use a parallel batt design instead of stacking batteries in series (1 exception is vaporflask), until a few weeks ago somebody pointed out the problem of the user inadvertently putting in the batteries the wrong way - that causes INSTANT shortout of the batteries.

That would be my biggest concern; you have to always, each and every time you change your batteries, remember to put the batteries in facing the right way.

 

[Lova]

I may be WAY wrong here, but from what I understand, when you have 2 batteries connected like they are in a mod box, they would be considered to be connected/wired in SERIES, which you add both battery specs together. So you would have 7.4V & 80A at your disposal from you battery's that you have there. Of course there is still voltage drop from your battery's and from the atty itself, ect..

Now, again, i could be completely wrong. And someone please correct me if I am!! But that is my understanding.

Hopefully this is accurate information and hopefully it helps you!!

Parallel would be 80 amps and 3.7-4.2V and series is 7,4-8.4v and 40 amps, when connected parallel the volts stay the same and amps are 2x of the amps of 1 battery, whileas in series it's 2x the volts but same amps. To be on the safe side, build to >0.2 ohms as 0.2ohm draws about 20amps of power but I'm not sure what the button or wires are rated in that boxmod you have

 

[Rickajho]

Not going to tell you what's safest in this scenario as AWT battery specifications are bit "optimistic" to say the least. Their 30 amp battery barely has 20 amp functionality. Test of AWT IMR18650 2500mAh (Yellow) UK Since AWT consistently overstates battery capacities compared to actual test results I wouldn't bet on that being anything close to a 40 amp battery. There's where you safety calculations fall apart.