70w Device Dual-Coil Build

[NightPlume360]

Hi everyone and thanks for stopping by!

I have an innokin Coolfire IV Plus, and I want to get into RDAs. Here are the specs of the device:

Battery: 3300 mAh
Maximum Output Wattage: 70w
Maximum Output Current: 26.5A
Maximum Output Voltage: 7.5V
Minimum Resistance: 0.1ohm

When I build my RDA, I would like to have a dual-coil set-up. So that means that if I'm vaping at 70w, then each coil will really only be putting out 35w, correct? (I'm still learning, so correct me in anything I say wrong or that I'm misunderstanding, please.) Currently I'm vaping my iSub Apex tank at 35w on a 0.5ohm coil, but honestly, I could go a little warmer (I would love to cloud chase). With this being said, I don't necessarily want to be vaping at max output wattage of 70w, because this seems slightly restricting (I want to get the most out of my device). Also, is vaping at maximum wattage bad for my device?

So I was wondering, if I use a lower resistance than 0.5ohm, then vaping at 70w would be even more powerful. Is this true? Would I be able to use a lower wattage with lower resistance coils and get the same vapor production that I was getting at a higher wattage on the 0.5ohm build? Any build suggestions for cloud chasing on my device?

Thank you for any help, it's much appreciated!

 

[IMFire3605]

Yes the mod can handle what it says it can, in other words can run full 70watts no problem if the resistance of the coil is not to low to pull more amps than the mod can provide, or is so high it can not push the voltage up to get to 70watts. Now, you asked, so I will say it, as I've seen it to many times, 70watts is basically red lining the motor of your car daily going down the race track, eventually that motor being pushed to its limit, something has to give, circuitry will wear and tear eventually sepperating due to the heat. Still, a dual coil RDA in the 50watt range is still a very enjoyable vape, plenty flavorful and still give a good vapor cloud. A 0.5ohm dual coil RDA is a bit different to a sub-ohm tank like the iSub Apex depending on the particular RDA. I classify RDA's into 3 categories, reduced chamber less airflow flavor RDA (example the Derringer), large chamber massive airflow clouding RDA (example the newer Mutation X 234), to an RDA with a balance of both flavor and clouding potential (example the older Mutation X Version 2).

Flavor RDA or want straight flavor, a higher resistance build will do this, example a 0.5 to 0.8ohm with 28awg or 26awg wire dual coil build, even a twisted 28awg wire dual coil will make a lot of flavor at a lower wattage with less airflow 35 to 50watt range. Clouding RDA or clouding build, here we enter lower resistance builds, like a 22 or 24awg wire build, even a 24core wrapped by 32 to 36awg Clapton wire build with a lot of airflow in the 70 or higher watts range will literally fog a room in just a few hits. A balance RDA or balance build allowing to go either way, I have a couple RDA's built this way, durable enough wire in the 0.3 to 0.4ohm range with 26awg parallel (2 wires per coil side X side to each other, similar principle to a twisted wire coil), that operate in a wide range of wattage 50watts up into the 80 to 100watts range. There is a lot that goes into RDA's and questions have to be asked where you want to be.

Being on a regulated mod, get a basic knowledge of not only "Ohm's Law" but focus on mainly "Watt's Law" (Watts/lowest battery charge state before mod shuts off=max amps the mod will ask from the batteries, 70watts/3.2v cutoff=21.875amps for example), find an Ohm's Law Calculator and coil simulator to allow you to begin to see what thicker wire (lower AWG number like 22awg) and thinner wire (higher AWG number like 32awg) does, how many wraps affect everything, start at higher ohms with thinner wire before going diving toward lower ohm builds with thicker wire, 28 and 26awg wire are great wires to experiment with, my 4 favorite wire gauges are 24, 26, 28, and 32awg depending on what I am building. Check out @Baditude 's blog, he has a lot of good information to help you along to help keep you safe or safer, and check out Steam Engine main page as a great vaping tool, has Ohm's Law calculator as well as a coil simulator and other great vaping programs you might get interested in.

GL, and don't hesitate to ask anymore questions or shoot a PM

 

[suprtrkr]

Hi and welcome. Cloud is not so much about raw power, it's about power radiated from the coil surface in contact with wet wick. In general, yes, the more power, the more vape. But you also have to use it efficiently. An excellent resource is Steam Engine, a coil design tool that will help you figure out how your coils will perform before you build them. Looking at the top of the page, click on the "Wire Wizard" tab far right. Then set it up for Clapton coils, using a 26ga core and a 32ga wrap with Kanthal A1 wire (I suggest this because this type of wire can be readily purchased pre-made on eBay and many other places). Put in a 4.5 wrap coil (that's a 5/4 wrap; both coil legs point in the same direction, and there are 5 wraps on top and 4 underneath) on a 3mm mandrel. Looking below, you'll see this yields a coil at .773Ω and a heat flux of 1.84mW/mm² per watt of power set on your machine. That may sound murky, but it is a measure of the power coming from the coil surface; most people find a satisfying vape between 80-180 mW/mm². If you run dual identical coils, that will divide the resistance in half, yielding a build in the .38Ω range, and it's a pretty good place to start if you want cloud. Applying 50 watts to that rig should yield 92mW/mm², and 70 should make 128.8mW/mm², right in the green zone. These figures (and the heat and cloud of the vape) can be changed, up or down, by increasing or decreasing the mandrel size or the number of wraps.

A hotter vape can be achieved using 2 x 28ga wires twisted into a 1mm twist pitch. Using that wire on a 6/5 wrap, 3.5mm mandrel, will yield a .929Ω coil, or a resistance of .465Ω for the pair. Those coils will give you 4.78mW/mm² for each watt of power applied, or a heat flux of 239mW/mm² at 50 watts, and 334 at 70 watts. That's far hotter than I like it, and it may risk burning you juice, but you may like it. It will probably be a tiny bit less cloudy than the above Clapton set, however, because while pumping out more power, a set of twists has less surface area than a Clapton coil. That's what I meant it being about power from the surface; both factors apply.

There is, as you can see, a great deal to learn about this, and no way to learn it save by diving in and trying, gaining some experience. There is a learning curve, but in time you'll get quite good at it. The key ingredient is safety. You have to stay within your mod's capability. You have a regulated mod, so the mod itself will work very hard to keep you safe, by not firing something it can't handle. Still, I recommend purchasing a coil tool kit, with a variety of mandrels and an ohmmeter, as this will give you what you need to do the work and stay safe at the same time.

Another point I have not mentioned is airflow. You have to balance the air with the amount of vapor being produced. If you have too much air compared to vapor, your cloud will be thin and you'll lose flavor. If too little, you won't get a lot of cloud and the vape will be hot. A really good, really flexible, and not too expensive RDA to start on would be a Mutation V4 or V4S (the difference is the style of the build deck, I like both.)

Once you have all that, all you need to do is practice. Coil building can be both frustrating and rewarding, albeit it's easier on a regulated mod than on a mech. It took me weeks to build my first coil that would vape at all without flooding or dry hitting; about 6-8 months before I got to the point where I could reliable get a good one every time; and maybe a year before I got good enough to build exactly what I wanted, and know that before I built it. Even now, years later, I still learn new things. But stick with it. It's a lot of fun for many people. And, if it turns out you are not one of these people, then buy a TFV4 tank with T3 coils, crank the watts to 70, and vape happy.

 

[TheRussianVaper]

Technically you can vape any allowable setup you want, I have a 75W mod that I take to work with me and .12 dual coils sitting in the RTA, vapes just fine but has a long ramp up time, so I ramp it up about 5 seconds every time I start.

If you want a fast ramp up time then you might want to be around .6 ohm each coil or higher with these low wattages.