# Ohm safety



## Greg (27/9/15)

Hi all.

First of all apologies if the questions I'm going ask have been asked and answered already but I need to know this for my specific setup. I've decided to start doing my own rebuilds and I'm concerned about ohm safety with my device. So, I have a Eleaf i stick 100 watt with a goblin mini and two efest IMR 18650 3.7 v 2900mAh batteries. I bought 28 g kanthal wire and made 2, 8 wrap coils for it. According to my i stick the ohms are 1.24. So is this safe for this device and batteries? I've have been searching the net and to be honest I have gotten quite confused, is it the case that the lower the ohms the more dangerous it can be? sorry for the noob question but I don't want to blow up my face...

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## Coco (27/9/15)

Greg said:


> According to my i stick the ohms are 1.24. So is this safe for this device and batteries?.



The iStick 100W can fire coils between 0.15 & 5.0 ohms. You are well within limits.

Danger territory would be on the very low side of the scale.

Reactions: Agree 2


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## Greg (27/9/15)

Coco said:


> The iStick 100W can fire coils between 0.15 & 5.0 ohms. You are well within limits.
> 
> Danger territory would be on the very low side of the scale.


Hi Coco, thank you for the reply! Okay good to know, I was also just worried about the batteries and if they would be fine according to the ohms and if the draw wouldn't be to much for them? After I did the rebuild and fired up and vaped the sound of the liquid vaping on the coil was not something I was used to , was just a bit worried that it might be pulling to much power or something... Like I said, noob questions..


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## Eequinox (27/9/15)

Greg said:


> Hi Coco, thank you for the reply! Okay good to know, I was also just worried about the batteries and if they would be fine according to the ohms and if the draw wouldn't be to much for them? After I did the rebuild and fired up and vaped the sound of the liquid vaping on the coil was not something I was used to , was just a bit worried that it might be pulling to much power or something... Like I said, noob questions..


I think you're questions are actually pretty good i always say the only noob question is the question not asked and i give you props for asking before something did go wrong

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## Greg (27/9/15)

Eequinox said:


> I think you're questions are actually pretty good i always say the only noob question is the question not asked and i give you props for asking before something did go wrong


Haha, thanks Eequinox, yes, rather ask than something blowing up in you face I always say

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## Andre (27/9/15)

You must make sure that the Amps your specific resistance coils will be pulling, can be safely accommodated by the batteries you are using.

*Step 1*: Do not believe the Amps marked on the battery. Go to this chart and see what is the continuous discharge rating of your batteries and to what Amps you can safely take it. Those Efests, you will see, are good to 15A.

*Step 2*: Go to this site to see what Amps your resistance will be using. In your case, with a fully charged battery, you will be discharging at a mere 3.39 A, which is way more than safe enough. Do you get a proper vape from those coils?

Above is simplistically put. Of course your iStick has certain settings and limitations, which play a role, but not necessary for this exercise. See this site to find the optimal range for coils on the iStick 100W, matched with your batteries.

EDIT: Even at 100W, you will only be using around 9 A, but your mod's Volt limit will in any event not allow you to go that high.

EDIT AGAIN: @Yusuf Cape Vaper has pointed out in another thread that the iStick 100W actually has its batteries in parallel (most other dual battery mods have their batteries in series), which means your actual continuous discharge current will be almost double that of one battery. In this case around 25A, which means you are even safer with that resistance.

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## Greg (27/9/15)

Hi Andre, thank you so much for this, it puts my mind at ease now, I will check all the links out and educate myself properly (as much as I can understand that is).

The vape I am getting is really good, like nothing I've had before . I'm going to need drop my nic levels way down now, I can already feel it on my chest just from vaping this afternoon..
Thanks again for the help!

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## GerharddP (27/9/15)

Without access to the net you can use Ohm's law V=I*R where V=volts , I=amps , R=resistance thus if you can work out the current draw from the batteries and see if its in the safe zone


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## jguile415 (27/9/15)

You're fine at 1.24 dude! How many watts are you vaping at? I'm running a .4 build on my subtank mini at 36w...no problems and the flavour is great


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## Jan (28/9/15)

The 1.24 sounds a bit weird? Gut feel is that it reads to high for that build


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## Greg (28/9/15)

jguile415 said:


> You're fine at 1.24 dude! How many watts are you vaping at? I'm running a .4 build on my subtank mini at 36w...no problems and the flavour is great


Hey man, I'm running it at 35w, and it's going great! I make my own juice with 10mg nicotine so I need to drop the nic quite a lot before I go higher on the watts..


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## Greg (28/9/15)

Jan said:


> The 1.24 sounds a bit weird? Gut feel is that it reads to high for that build


Yes, I think my mod isn't reading 100%, yesterday it was reading at 1.24 and this morning it was at 0.79??? Not sure, maybe I didn't build it correctly, it was my first attempt so I will break it down and rebuild again tonight and see what happens


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## WHeunis (28/9/15)

Greg said:


> Yes, I think my mod isn't reading 100%, yesterday it was reading at 1.24 and this morning it was at 0.79??? Not sure, maybe I didn't build it correctly, it was my first attempt so I will break it down and rebuild again tonight and see what happens


First step, just check that your screws are tightened down proper on your posts.
Second step, make sure that no part of the coil (including any tails where you trimmed it) dont touch any parts of the atty chamber, other than the posts.
Step 3, make sure that that little xtension at the bottom of the atty (with the airholes) is tight and secure.

After that, yes you may have to rebuild

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## Andre (28/9/15)

Greg said:


> Yes, I think my mod isn't reading 100%, yesterday it was reading at 1.24 and this morning it was at 0.79??? Not sure, maybe I didn't build it correctly, it was my first attempt so I will break it down and rebuild again tonight and see what happens


I have edited my post above - just found out the iStick 100W has its batteries in parallel, which makes your build even safer.

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## Greg (28/9/15)

Andre said:


> I have edited my post above - just found out the iStick 100W has its batteries in parallel, which makes your build even safer.


Thanks Andre!


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## Greg (28/9/15)

WHeunis said:


> First step, just check that your screws are tightened down proper on your posts.
> Second step, make sure that no part of the coil (including any tails where you trimmed it) dont touch any parts of the atty chamber, other than the posts.
> Step 3, make sure that that little xtension at the bottom of the atty (with the airholes) is tight and secure.
> 
> After that, yes you may have to rebuild


Thanks for the tips! Will check and follow all of that!


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## Silver (28/9/15)

Greg said:


> Hi all.
> 
> First of all apologies if the questions I'm going ask have been asked and answered already but I need to know this for my specific setup. I've decided to start doing my own rebuilds and I'm concerned about ohm safety with my device. So, I have a Eleaf i stick 100 watt with a goblin mini and two efest IMR 18650 3.7 v 2900mAh batteries. I bought 28 g kanthal wire and made 2, 8 wrap coils for it. According to my i stick the ohms are 1.24. So is this safe for this device and batteries? I've have been searching the net and to be honest I have gotten quite confused, is it the case that the lower the ohms the more dangerous it can be? sorry for the noob question but I don't want to blow up my face...



Hi @Greg, just a headsup

If you build a 8 wrap coil using 28g wire, depending on the diameter of the coil, it usually comes out at between 1 ohm and 1.5 ohms or thereabouts. I assume you used about 2.5mm, so I would guess around 1.4 ohms or so.

That would make a parallel setup (i.e. two of these coils connected in parallel) around 0.7 ohms or thereabouts, not 1.24 ohms

So when it read 0.79 ohms this morning, that was probably the correct reading.

Check if the screws are catching the legs of the coils tightly enough.

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## jguile415 (28/9/15)

@Silver beat me to it

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## Greg (28/9/15)

Silver said:


> Hi @Greg, just a headsup
> 
> If you build a 8 wrap coil using 28g wire, depending on the diameter of the coil, it usually comes out at between 1 ohm and 1.5 ohms or thereabouts. I assume you used about 2.5mm, so I would guess around 1.4 ohms or so.
> 
> ...


Hi Silver, yes I built it over a 2.5 bit. Thanks, I will take more care on my second build and make sure the screws are tight enough. This was probably the most difficult part of the build for me because I kept on over tightening the screws and breaking the wire then I would under tighten and they would pull out when I was adjusting the coil into a better position..it's quite a fine line between over and under tightening I've found


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## Silver (28/9/15)

Agreed

If the screws are breaking the wire, you can take them out and file them a bit 

Also, what i find sometimes helps is to put the coils in, then do a few test fires, then when its cooled down, check the screws again. Sometimes the wires move fractionally from the heatkng up and cooling down and then if you tighten it again it holds better. Doesnt always work like this but sometimes it does.

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## Greg (28/9/15)

Silver said:


> Agreed
> 
> If the screws are breaking the wire, you can take them out and file them a bit
> 
> Also, what i find sometimes helps is to put the coils in, then do a few test fires, then when its cooled down, check the screws again. Sometimes the wires move fractionally from the heatkng up and cooling down and then if you tighten it again it holds better. Doesnt always work like this but sometimes it does.


Good advice! Will definitely do this, thanks

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## Greg (28/9/15)

Thanks to everyone who gave input here! Sound advice from the pros!! Excellent forum, glad I joined

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