What are my Ohm limits?

[Entities19]

I recently bought my first mod setup and i am looking into rebuilding the coils myself. I have been doing a lot of research on the coils and how different gauge wires and number of wraps affect Ohm resistance. The build the vape shop put on it is running 0.37ohms. My setup is a HCigar Nemesis Clone with an Efest 18650 imr 2500mAh and a Patriot RDA. What is my safe ohm range for this set up and should i be concerned about 0.37? I like the sub ohm hit, i just don't want a battery to vent while I'm 60mph on the highway. Thanks!

 

[Lefty]

http://www.steam-engine.org you can plug in resistance and set voltage for a fully charged battery and find the amperage or current required for various builds in the Ohm's law section. The .37 build would draw 11.35 amps at 4.2 volts. Well within the 20 amps continuous rating of your Efest. Assuming of course that basic battery safety is followed and you check the resistance and for shorts before you fire up your new build on the Nemesis.

 

[Entities19]

Perfect. Does the risk of a vent go up as the battery weakens? How would i know the battery is getting to low for the build without testing it without a multimeter? From what i have read my vape will get really weak before i get to that point, but i would like to be sure for obvious reasons. How do identify a short?

 

[indian ocean steamcloud]

Hi Entities , Like Lefty says go to the link he provided and actually USE the calculator yourself. Try doing the following as an exercise....

-in the top box Resistance (read OHMS) .... set it to 0.4 (or 0.3) it only allows you to get that close to your actual resistance of 0.37)
-then set the Voltage box to 4.2
then using the little up down adjuster that appear adjust the volt downwards (this is what happens as your battery is used)
keep your eye on the numbers in the box labelled Current (read AMPS)
you will see that the numbers DECREASE. as your Voltage decreases
This shows you that your battery becomes LESS at risk of venting the less voltage it provides.

If you intend building coils for your dripper yourself you REALLY must have either a multimeter or an Ohms tester and know how to use it/read it properly. Perhaps the vape shop where you bought your gear will show you how to do that.
Also you must know the Continuous amp rating of the battery you are using.

Good luck and keep researching. You are headed in the right direction.

 

[Lefty]

Beat me to it. What he said.

 

[Entities19]

Oh okay I see what you are saying. I have an ohms tester and i plan on investing in a one of the multimeters you can screw into your mod, speaking of that does anyone have one they recommend or have good experience with?

With continuous amp rating, from my understand 15C=15A continuous?

I also saw an ex. equation for a 1600mAh 15C battery that was 1600x15=24000 ro 24A. What exactly is going on there? Sorry for all the questions, i just find this very interesting and i want to learn as much as i can so i can be safe and pass on the good habits to future vapers!

 

[Lefty]

Depends on the mAh rating of the battery. 15C=15A on a 1000mAh battery. Or 15X1=15A. 2000mAh 15X2=30A etc.
The meters that screw onto your mod are usually just inline volt meters. The ohm's tester should be sufficient if it's reasonably accurate.

 

[Entities19]

So for every 1000mAh you would multiply the continuous amp rating by 1 more?
2000mAh with 10C=20A
3000mAh with 10C=30A

So i keep the amp draw below my batteries continuous amp rating, always ohm test my coils before test firing, watch my battery voltage, and use something like steam engine to check myself.

One last question, if my battery does short and i feel it heating up in my mod, should i leave it in the mod and put it somewhere out of the way, or can i quickly take the battery out and toss it in my driveway to cool? It wouldn't be very confidence inspiring to blow up my first mod.
Thanks for your help!

 

[BabyFartsMcGeezax]

Not really... it's all based on the C rating/multiplier.
6-C 1000mAh= 6,000mA...or 6 Amp continuous rating.

What efest are they? 30, 35, or 20 Amp? The 20 Amp batteries are far from being 20 Amps..the 30 Amp is a vtc4..35 Amp is a LG HE2..

When you're battery is venting... you'll know...if it's hot enough to warrant it, throw your mod...far away from people.. I've heard of a few close calls lately, mainly with 26650 mods..

 

[Entities19]

The battery is a 2100mAh IMR 18650 3.7V LI-MN 30A

 

[Lefty]

I just shorthanded the multiplier 2200mAh to 2.2 1600 to 1.6 etc.. The C rating times the mAh equals the amps (or ma without the shorthand). The 2100 30amp Efest is reputed to be a Sony VTC4. I said 20 amp because you said 2500mAh and that is as BFM said likely a LGHE2 which is a 20 amp continuous and 35 amp pulse battery that Efest labels 35A.

 

[Lefty]

If your mod shorts you will know it pretty quickly. Unscrew it pretty much anywhere if it's not too hot yet and stop the short. If it's too late for that I wholeheartedly agree with tossing it away from people. You can always replace the mod if it's toast.

 

[Entities19]

Looking at that ohm calculator, i could almost go as low as 0.14ohms with that battery right? Not that i would ever want to, im not a cloud chaser, i just like a solid hit.

 

[Lefty]

Theoretically I guess but I wouldn't trust any Efest at that resistance myself. I'd prefer a bit of a buffer between ratings and real world stress but that's just my opinion. Heck the .37 build is way hotter (literally) than I'd prefer in a vape.

 

[Entities19]

I agree, I'm not going to trust a company's claims 100% at the expense of my face. I really enjoy how this build vapes, but I'm going to try a build around .5 or .6 to see how i like it. Thanks again for the information!

 

[BabyFartsMcGeezax]

Again...

The 20 Amp 3100mAh efest isn't close to a 20 Amp continuous rating..or 3100mAh more like 6.8 Amps..

The 30 Amp efest is just a Sony vtc4/30 Amp continuous 2100 mAh.

The 35 Amp efest is a LG HE2..20 Amp continuous, 2500 mAh..

 

[Lefty]

Why again? You may be willing to assume they won't change horses under those wraps if it suits them and that they are all first bin cells. I prefer to qualify it, that's all.

 

[Jackson]

What efest are they? ...35 Amp is a LG HE2..

When you're battery is venting... you'll know...if it's hot enough to warrant it, throw your mod...far away from people.. I've heard of a few close calls lately, mainly with 26650 mods..

Which BTW the LGHE2 is rated by LG as 20A Continuous.

 

[Entities19]

Just finished my first build. I don't think they are to bad for my first coils. I used 26G Kanthal and 6 wraps around a 7/64 drill bit.


I just need to work on being consistent, one came out tight but crooked, and the other came out pretty loose, i couldnt get it to hold together. I also may have used a bit to much cotton, it hits just fine

Produces a good amout of vape. It has a nice cloud and a good throat hit, and actually produces more flavor than the build the guy at the vape shop did for me.

Came out at .41 ohms which is a little more than the .37 the vape shop did. I was aiming for closer to .5 or .6 so next time ill do one more wrap.

My coil next to the old one.. Now i see the affect of using all VG juice, i only used these coils for a few days.


Feel free to give me tips on how to make my next build better!

 

[BabyFartsMcGeezax]

I wish I could show you my first coils...on mesh and silica. Lol.

But only thing I think I can recommend is a coil jig, or a proper tool. I use a multimeter lead or screwdrivers that are ~2mm. I can get a good grip on the tool and bottom leg..it's all about keeping the same tension while wrapping the coils..kinda hurts my hands when I use something like a toothpick.
.. just assuming from the drill bit in two pictures.

 

[Entities19]

Yeah I'm going to buy a small screwdriver, i have one but its a little to big. Ill just keep practicing. I'm going to practice a little more before i try nano coils or whatever they're called. I don't understand how people make those artistic woven coils and stuff, seems like it would take days for one coil.

 

[MKPM]

Highly affordable coil jig at VaporJoes. I used to scoff at such things...but I use less wire now, and wind TIGHT coils that seem to perform once the mandatory pulse/pinch/pulse/pinch has been done.

 

[Lefty]

I've taken to using a variable speed drill to relieve some tendonitis. I have a battery powered one that stands nicely on it's base. I just reverse the bit so the shank is out and slide the wire end into the gap between the chuck points as far as it will go then put a little tension on the wire (still on the spool) at a 90 deg angle and go. It's not too hard to count turns and you get a nice tight wind. I keep a loupe handy to double check and just pull on one lead with needle nose to unwind any extra. I keep it on the bit until installed and positioned. Quite often it's good the first time I pulse it. If not I re-insert the bit and give it a slight pull and that gets it almost every time without squeezing. My torch is sulking on the end of the desk.

 

[indian ocean steamcloud]

Looks like you are going great guns there Entities The more you build coils the better you'll get

+1 for Lefty's advice about keeping the coil on the bit until you have it fully installed. When I build dual coils I use 2 drill bits...I don't find that they get in the way.

One thing I'd suggest is not having so much cotton on the build deck and underneath your coils. IMHO the cotton should be a wick not a juice storage facility. Leave an open area directly under your coils to allow for better airflow around them.

 

[Subohmer]

Just finished my first build. I don't think they are to bad for my first coils. I used 26G Kanthal and 6 wraps around a 7/64 drill bit.


I just need to work on being consistent, one came out tight but crooked, and the other came out pretty loose, i couldnt get it to hold together. I also may have used a bit to much cotton, it hits just fine
View attachment 7246
Produces a good amout of vape. It has a nice cloud and a good throat hit, and actually produces more flavor than the build the guy at the vape shop did for me.
View attachment 7247
Came out at .41 ohms which is a little more than the .37 the vape shop did. I was aiming for closer to .5 or .6 so next time ill do one more wrap.
View attachment 7248
My coil next to the old one.. Now i see the affect of using all VG juice, i only used these coils for a few days.
View attachment 7249

Feel free to give me tips on how to make my next build better!

I watched all of Rip Trippers videos on you tube he is awesome at teaching people how to build any and all coil setups. If you want to get good fast then subscribe to his YouTube channel. Worked for me. Good luck.

 

[Entities19]

fransican - i was actually looking at getting their coil jig. I think it would be a good jump start for me to wrap more consistent coils

Lefty - I don't have a drill and would rather not invest it one, but if i ever do get a cheap one ill probably use it to straighten Kanthal wire, and maybe build a zipper coil!

indian steam cloud - Thanks man! That is good advise, ill have to do that when i wick it again

Subohmer - I watched a few of his, but im going to watch the rest of him, hes entertaining to watch and has a lot of good information, he seems to know what he is talking about.

 

[BabyFartsMcGeezax]

You'll be out building everyone in no time.

I recommend getting something with wider airflow(or a drill=the best AFC)..there are a lot of bad ass authentic and affordable atomizers coming out... I'm really interested in the holmes and two wind atomizer..the clt v2 is pretty awesome too...but I have friends that got patriots when they first came out, and it's still their go-to atty..so I'm just forcing myself on you..

You're doing awesome for what you have to work with.. I approach everything with a thick head..so I still haven't watched a build video...except when I got my first kayfun clone, that had HUGE wick wells cut into it..I liked watching that vaperev video..I like those kind of girls.

I think fransican gave me hate for this build..I don't know why.. thinking I may get hot legs or something.. doesn't produce as much vapor being that close to airflow? I don't know..I don't care.. while the latter is a valid point, I don't get hot legs.. I've only experienced hot legs on the first 0.2 Ohm build with my origen.. I dunno.

But I love my twisted and pressed kanthal..I haven't figured out which I like the best...first picture is loose twist and pressed at much lower pressure..second is tight with as much pressure as I could get on it..it doesn't cool off as well as the looser twist..gotta take an after pull with it to help it out.

This isn't pressed... just fun.. took only 20 minutes, with an extra hand to tighten positive contact..works great with modded tobh cap..or even the mutation x cap works decently..but I have (had) a special tobh for this build. Edit- didn't use wicks.. just stuffed a rayon bed/cloud under it.

So just apply what everyone's mentioned, and you'll be boss status..

Cuz like I said, I wish I could show you my first coils...lol

I tried wrapping a couple without a tool or anything...the air was my tool.

 

[Lefty]

Freehand eh? Pretty radical.

 

[BabyFartsMcGeezax]

Lol...yeah..I was trying to think outside the box.

Unfortunately, you can't make a good circle with air..and with 30awg...pretty rickety.

 

[Entities19]

Well thanks for the support! I'm excited to start twisting coils and trying flat wire, I made my first parallel coil yesterday. Came out at .32ohms, vapes like a champ. Hopefully with practice, I'll be wrapping coils with the best of em!

 

[BabyFartsMcGeezax]

Sending you a pm..