what exactly is sub ohm? and what is the safest ohm to run on dual coils

Status
Not open for further replies.

Statistic

Ultra Member
ECF Veteran
Verified Member
Apr 7, 2013
2,104
6,293
United States
Taking a guess at your resistance is not safe. Measure it.

What batteries are you using and what is their continuous amp limit (C rating times mAh) ?

Is the measured resistance of your atty drawing amperage in excess of the continuous amp limit of the batteries you are using?
 
Last edited:

Statistic

Ultra Member
ECF Veteran
Verified Member
Apr 7, 2013
2,104
6,293
United States
This calculator will help you easily determine the amperage you are drawing from your batteries. Plug in 2 of the 4 variables and the calculator will give you the other two. Use the resistance of your atty and the voltage of your battery. It is common to use 4.1v for what we're doing in this here vape hobby.

Online Conversion - Ohm's Law Calculator

If you don't know what the amp limit for your batteries then what batteries are you using? I'm sure it can be found with a little google-fu ;)
 

Statistic

Ultra Member
ECF Veteran
Verified Member
Apr 7, 2013
2,104
6,293
United States
Eh well "protected" batteries are not the best fit for mech/sub ohm vaping. What brand are they?

You should get some proper IMR batteries (AW IMR, MNKE, etc) to go sub ohm like that.

How did you measure your resistance, exactly? With both coils installed if the atty is measuring 1.9 then it's 1.9. You only divide by the number of coils if you measure each coil individually

Also, not being a jerk here, there is no "safe sub ohm vaping in dummy terms". If you don't know what amperage you are drawing from your batteries and the max discharge rate for them then at best you are guessing it might be safe.

Don't be intimidated by the numbers and terms, there is no need to keep things in dummy terms. This stuff is easy to learn ;)
 

Statistic

Ultra Member
ECF Veteran
Verified Member
Apr 7, 2013
2,104
6,293
United States
Hmm.. 4000mAh is definitely.. optimistic.

The PCB's in that battery are rated for 4.1a. If your atty is .9ohm you are pulling about 4.7a and should be tripping them when fully charged. Most good quality 18650 size IMR's are rated for 10a or more. The AW IMR 1600's (18650) are rated for a whopping 24a.

They (your ultrafire's) are not high drain batteries and are more appropriate for use in say, a flashlight. If the PCB fails and that battery melts down you are going to have a much uglier situation on your hands than if you were using the appropriate type of batteries. IMR are not protected, they are "safe chemistry" and are rated for high drain applications. If an IMR were to melt down they do it in a less volatile fashion than Li-ion.

Rule #1 for mechanical vaping - Do not skimp on batteries.
 
Last edited:

Statistic

Ultra Member
ECF Veteran
Verified Member
Apr 7, 2013
2,104
6,293
United States
Ahhhhhhh its all becoming so clear! Lol I have an orange mnke imr-18650 but took it out because I misunderstood how to test the ohms, I don't want to go sub ohm. I need to do a lot more research before I go there. I measured the ohms with both coils already attatched. Can't find the voltage on my orange bat.

Ah ok cool :) we're clearing some of the fog now

Those MNKE's are a MUCH better fit for mech vaping, sub ohm or not, than any battery that ends with the word "fire" ;)

The MNKE's are 3.7v batteries and should measure 4.2v +/-.02v coming off the charger

At 1.9ohm you're pulling about 2.2a from a fully charged (4.2v) battery, which must be why the xxxxfire's are even heating those coils at all
 

Randy C

Ultra Member
ECF Veteran
Feb 17, 2012
1,181
2,918
SW Florida
Also, not being a jerk here, there is no "safe sub ohm vaping in dummy terms". If you don't know what amperage you are drawing from your batteries and the max discharge rate for them then at best you are guessing it might be safe.

Don't be intimidated by the numbers and terms, there is no need to keep things in dummy terms. This stuff is easy to learn ;)

I strongly advise folks to do the research BEFORE experimenting with RBA's.
 

armoworrior

Senior Member
ECF Veteran
I am getting tired of the I'm a noob and wanting to do sub ohm why are my coils or this or that not working right. Because you didnt do research to see how to do it right for your self. Please dont blindly jump into the mech world its not easy sometimes. Quite confusing. Learn omhs law wrap some coils build a protank coil then lets talk mech.
 

Statistic

Ultra Member
ECF Veteran
Verified Member
Apr 7, 2013
2,104
6,293
United States
I am getting tired of the I'm a noob and wanting to do sub ohm why are my coils or this or that not working right. Because you didnt do research to see how to do it right for your self. Please dont blindly jump into the mech world its not easy sometimes. Quite confusing. Learn omhs law wrap some coils build a protank coil then lets talk mech.

I'm getting tired of people chastising others for reaching out and saying "I need help understanding this stuff".

People don't know until they know. Giving them a hard time for asking the questions is only going to make it more intimidating and harder to ask the questions.

It's not like she wrapped up a triple twisted 26g at .05ohm.. In fact she isn't even anywhere near sub ohm as it turns out, her dual coil is just under 2ohm. She's just learning the ropes, take it easy, bro.
 

Endor

Super Member
ECF Veteran
Verified Member
Jan 31, 2012
687
2,074
Southern California
Whether she has a torch or allen wrenches is irrelevant, as she's asking whether her slightly sub-ohm coil is safe.

Mrs C, the AW IMR battery your husband found will work just fine with a 0.9 ohm coil. It's all Ohm's law math. My all-day vapes are a collection of genesis-style atomizers (SS mesh) running 0.8ohm on either AW IMR 2000mah or Panasonic CGR18650CH batteries. Ohms Law says I'm pulling about 4.5-5amps at that setup. Both of these batteries are rated at 10 amps continuous, and I'm only pulling half of that, so there is plenty of safety factor here. In fact, neither of these batteries even get warm, and I'm a chain vaper.

Hope this helps... :)
 
Status
Not open for further replies.

Users who are viewing this thread