Okay so now one is able to explain it because somewhere down the line( I am an okay vaper. I know most of my stuff) I need a good starting point. I have the Samsung r 18650 batteries. Dual parallel in a Dimitri box mod. 4.2 volts each that comes out to 8.4 volts total right? I was told my 1.2 ohms is better than .5 ohms. Why? I have a Dimitri mod (as I said and if it helps anything, unregulated like I like them) but what would be a "better ohm" to vape? I DO NOT go very low. I barely even used my .5 coil just cause of what I was told. Am I wrong? should I switch them up or rebuild another coil?
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Have a glance at the Ohm's Law Calculator. Reference thereto, and using the figures you provided, I found: 8.4V across a .5 Ohm coil makes 141+ Watts and draws almost 17 amps from your batteries. Using the 1.2 Ohm coil, the amp loadings are 7 and the power is almost 59 Watts. When you say "Samsung r batteries" I assume you mean Samsung 25R batteries, a popular choice and a good one although I would not use them in a mech mod. If so, those are 20 amp batteries. While 17 amps is technically within this limit, I for one think it is shaving the safety margin very thin. I recommend not loading batteries above 50% of their capacity if it can be avoided. Using your mod and those batteries (and the calculator again) I would not build below .84 amps as this gives a 10 amp load at the full charge of 8.4 volts. The 1.2 Ohm coil you mention should be safe to use with that mod and those batteries.
Now, as to *why* all this works... that's a complex issue and one you would be well advised to study until you understand it if you intend to be a mech modder. The bottom line is, Ohm's Law describes the relationship between volts, amps and ohms, and they are interdependent. When you change one, the others follow suit. Yes, in my opinion, a .5 ohm coil is "very low" at 8.4 volts. It would not be if you had a parallel mod that made 4.2 volts. Then, the battery amperage would double because you had two of them, and you could safely built to a 20 amp loading. That would be a .21 ohm coil. Note however, a .21 ohm coil at 4.2 volts makes 84 watts, and a .84 coil at 8.4 volts also makes 84 watts. There is no difference in the power applied to the atomizer, just in how you get there, and how you (safely!) draw the current from the batteries.
Edit: On re-reading, where you have made your mistake is thinking you have a parallel mod. If the website is correct, you do not. It is a series mod.
Now, as to *why* all this works... that's a complex issue and one you would be well advised to study until you understand it if you intend to be a mech modder. The bottom line is, Ohm's Law describes the relationship between volts, amps and ohms, and they are interdependent. When you change one, the others follow suit. Yes, in my opinion, a .5 ohm coil is "very low" at 8.4 volts. It would not be if you had a parallel mod that made 4.2 volts. Then, the battery amperage would double because you had two of them, and you could safely built to a 20 amp loading. That would be a .21 ohm coil. Note however, a .21 ohm coil at 4.2 volts makes 84 watts, and a .84 coil at 8.4 volts also makes 84 watts. There is no difference in the power applied to the atomizer, just in how you get there, and how you (safely!) draw the current from the batteries.
Edit: On re-reading, where you have made your mistake is thinking you have a parallel mod. If the website is correct, you do not. It is a series mod.
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If its parallel batt, the voltage stays at 4.2. The mah will double and theoretically the amp limit/ handling doubles as well. Battery sag should be lighter as well.
Awesome thank you so much. 1.2 got it. I even understood every other thing you said. I have been studying this stuff for a few months now and I just got confused real quick. Now my Dimitri also comes as a mini which allows one batter so it would just be straight 4.2 volts. anything you can say about that? Also, if the Samsung 25r are nice batteries but not recommended, what is? I know of a few buddies who use those or Efest but heard more preferable things about the 25r. I was also told to stay away from anything with "fire" in the name.
Well done. Again, use the calculator. You plug in any two values-- you know your voltage, plus any other one-- and it will calculate the other two for you. If you have 25r's and you don't want to load them above 10 amps, put in 4.2 volts and 10 amps and read off the minimum ohms and how many watts it will make. Or any other combination. As I said above in my edit, where you made your mistake is thinking you have a parallel mod. If the website is correct, it is a series mod. That works like this: Each Sammy 25R is good for 4.2 volts and 20 amps. Safe loading on each is 4.2 volts and 10 amps. In series, two of them give you 8.4 volts and 10 amps. In parallel, you get 4.2 volts and 20 amps. A single battery-- mini mode or whatever-- is good for 4.2 volts and 10 amps. You should build your coils appropriately to that. As I said, Ohm's Law describes a *relationship,* not an absolute value. What ohms are safe depends on the voltage and how many amps may be safely drawn from the battery. That's why we use the calculator. To give you a number, 4.2 volts and 10 amps for a single battery plugged into the calc will give you a .42 Ohm coil and 42 watts as your answers, so don't build below .42 ohms.
The 25Rs are good batteries, as I said. I can recommend them in any regulated mod not exceeding 100 watts. In high-power applications, or mech mods, I prefer the Sony VTC4s. These are also nominally 20 amp batteries, but according to @Mooch 's bench tests-- the results are in chart form here-- the VTC4s can absorb loads to 30 amps without dangerously overheating. This isn't good for them, it shortens their life. However, in case of an autofire or a stuck button or-- God help you-- a short, it can extend *your* life. I think the thicker safety margin is worthwhile, even though you have to give up 400mAh storage capacity versus the 25Rs.
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I have been waiting for someone smart like you oh my lord. Thank you so much I have such a better understanding now. All in all I will use that calculator and switch to some Sony VTC4s and go from there. Thank you for potentially "saving" my life.
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You are welcome, my friend. Helping people understand what their mods are doing is why I am here. I am less concerned with regulated mods as they are fairly safe, but mech mods can be dangerous in the hands of people who don't understand what to do with them. Use the calculator, as you have said, and it will not be long at all before you come to understand the relationship between volts, amps and ohms, and how different combinations of them change the wattage you are applying to your attys. Ohm's Law appears confusing at first, but it simplicity itself: it takes one volt of potential to push one amp of current across one ohm of resistance. All the rest of this, no matter how complicated it appears, still fits neatly within that one sentence.
Let me also suggest you consider the use of a coil calculator like Steam Engine. I find it a great help when designing builds to achieve different purposes, not merely to fix a safe ohm factor. It looks complex to use, but it gets easier with practice. You set all the variables: desired resistance of the finished coil, the wire size you want to use, the diameter of the mandrel on which you wish to wind it, what kind of coil-- be it single or dual or cross legs or parallel, whatever-- and it will tell you how many wraps to use and show a little picture of what the finished one should look like. If you find your designed coil you're using is too big to fit neatly on the deck, or too long to wick efficiently in the center, or takes too long to heat up and make vapor, you can start switching up the parameters of the coil to make it do what you want. Too long? Wrap it on a bigger mandrel and it'll shorten up some. Too fat? change to a smaller size wire and wrap on a smaller mandrel, etc. Of particular utility, I find, is the "heat flux" section off to the right. This tells you how many milliwatts of power you are applying to each square millimeter or coil wire surface area. Juices respond well to different heat fluxes by their nature. You can set how many watts you are applying to the coil you have built (change the resistance from the designed resistance to what you actually measured on your ohmmeter for best accuracy) and read off mW/mm^2. Coils only make vapor at the surface (duh!) and this tells you how hot and how much power you are making each square millimeter of your coils surface. Given you are using a mech mod, your watts are fixed within narrow limits by battery voltage, battery permissible amps and coil ohms. Moreover, they will change with every puff, from full charge battery down to "too weak to vape" and you reach for your spare batteries. When I am using a mech, I use the Ohm's Law calculator to find the applied watts at full charge volts of 4.2, and then the applied watts at the "change your batteries" voltage of 3.5, and apply those two wattage values to the heat flux section of Steam Engine to get an idea of how much and how hot a vape will be coming off my coils. I often find this causes me to re-think my builds a bit before I actually build them.
To give you an example; I recently got a Dark Horse dripper. I wanted to use it on a one-battery mech-- a Smok Magneto V1 tube mod-- which uses the same "4.2V and 10A" restrictions we discussed last night for one battery. Knowing I could not build below .42, that's where I started. I set Steam Engine up for dual slick wire parallel coils, 28ga Kanthal A1 and .45 ohms on a 3mm mandrel. That all worked out, but when I put the maximum full charge watts of 42 in the heat flux section I was way up in the red zone, putting nearly 300 mW/mm^2 on the wire. This would have been a scalding hot vape (to me, some people like it) and might have burnt my juice so it tasted nasty. So I backed off of it. I eventually worked my way out to a .6 ohm coil on a 2mm mandrel-- I did all this before twisting one piece of wire-- to give me heat fluxes between 185 to 135 mW/mm^2 from full charge to depleted. Then I built that coil and installed it. It measured out to be .66 Ohms and it makes enough flavor to make your eyes water and blows enough steam to fill a room with 2 or 3 puffs-- and all that on a one-battery mech at no more than 25 watts.
If you're a cloud chaser-- I suspect you are, those are the dudes who use series mech mods-- fine: the more watts you can put on the coil, the bigger you can chuck, all other things being equal. And all this is a little overwhelming at first, as I clearly understand. It was to me, too, and I already understood ohms law before I started vaping. What I am saying is, as you learn more, and grow more confident, there's a lot out there to learn and more to do than merely chucking clouds. So have fun and enjoy the journey. Above all stay safe and, once you have built your safety fence you always stay inside, start experimenting. Mech mods-- I love them-- are harder and more challenging to do than regulated mods. And they are also more satisfying when you learn how to make one do what you want. Any idiot can build any old coil and set the wattage at 27 to see what they get. Building a mech to yield the same 27 watts while still giving you the vape you want is a different matter, and a lot more fun when you get there. You just have to keep your chin up through repeated failures until you *do* get there
Agree with @suprtrkr completely. A clear understanding of how to use every feature Steam Engine has to offer will go a LONG way in coil building. Understand your mods, whether regulated or unregulated(emphasis on unregulated). Great question to ask why they recommend a 1.2 ohm build rather than a .5. It will ultimately by your call, you must figure out what settings produce a satisfying vape for you, if you understand the theory, and how to use Steam Engine, then you will understand how to manipulate your devices to produce the vapor you want.
+1 to @Darth Omerta . This is about what *you* want your mod to do. I-- or he, for that matter-- can tell you how to not blow yourself up. But only you can figure out when you have a vape that you like. Have fun with it, as I said; do not become frustrated or discouraged. You have chosen a mech mod, and this is the more difficult path. Fine, so be it: you have chosen. Understand it's going to take some time and effort to get where you want to be; and that the tool you have selected is inherently more limited than a regulated mod. Then learn where those limits are, and how to make it do what you want within them. The result is far more satisfying when you do get there. And if it's not, then you have made a mistake in thinking you are a mech modder, so sell the Dimitri and buy a Segelei 150 and a Freemax Starre and chuck clouds
Side note - if you're going to run dual batteries, make sure they're a "married (never to be divorced )" set. It's best to keep them matched so that their drain and charge cycles are identical. I think I also noted in other places that you would flip-flop the installation of the batteries. e.g. if Battery A went in the left side last time, install Battery B there the next time. Should help keep the drain consistent for the life of the batteries.
)" set. It's best to keep them matched so that their drain and charge cycles are identical. I think I also noted in other places that you would flip-flop the installation of the batteries. e.g. if Battery A went in the left side last time, install Battery B there the next time. Should help keep the drain consistent for the life of the batteries.
Excellent point, Dinger, and I missed it. Yes, do please marry the batteries and keep them together. Switching positions in the mod is also a good idea.Side note - if you're going to run dual batteries, make sure they're a "married (never to be divorced
But....
What do you do if your mod takes 3 18650s and polygamy is illegal where you live?!?!?!?!?
What do you do if your mod takes 3 18650s and polygamy is illegal where you live?!?!?!?!?
Have plastic surgery, change you name and move to Des Moines. You had to ask?But....
What do you do if your mod takes 3 18650s and polygamy is illegal where you live?!?!?!?!?
But....
What do you do if your mod takes 3 18650s and polygamy is illegal where you live?!?!?!?!?
BWAH HA HA HA HA. Touche'
You are welcome, my friend. Helping people understand what their mods are doing is why I am here. I am less concerned with regulated mods as they are fairly safe, but mech mods can be dangerous in the hands of people who don't understand what to do with them. Use the calculator, as you have said, and it will not be long at all before you come to understand the relationship between volts, amps and ohms, and how different combinations of them change the wattage you are applying to your attys. Ohm's Law appears confusing at first, but it simplicity itself: it takes one volt of potential to push one amp of current across one ohm of resistance. All the rest of this, no matter how complicated it appears, still fits neatly within that one sentence.
Let me also suggest you consider the use of a coil calculator like Steam Engine. I find it a great help when designing builds to achieve different purposes, not merely to fix a safe ohm factor. It looks complex to use, but it gets easier with practice. You set all the variables: desired resistance of the finished coil, the wire size you want to use, the diameter of the mandrel on which you wish to wind it, what kind of coil-- be it single or dual or cross legs or parallel, whatever-- and it will tell you how many wraps to use and show a little picture of what the finished one should look like. If you find your designed coil you're using is too big to fit neatly on the deck, or too long to wick efficiently in the center, or takes too long to heat up and make vapor, you can start switching up the parameters of the coil to make it do what you want. Too long? Wrap it on a bigger mandrel and it'll shorten up some. Too fat? change to a smaller size wire and wrap on a smaller mandrel, etc. Of particular utility, I find, is the "heat flux" section off to the right. This tells you how many milliwatts of power you are applying to each square millimeter or coil wire surface area. Juices respond well to different heat fluxes by their nature. You can set how many watts you are applying to the coil you have built (change the resistance from the designed resistance to what you actually measured on your ohmmeter for best accuracy) and read off mW/mm^2. Coils only make vapor at the surface (duh!) and this tells you how hot and how much power you are making each square millimeter of your coils surface. Given you are using a mech mod, your watts are fixed within narrow limits by battery voltage, battery permissible amps and coil ohms. Moreover, they will change with every puff, from full charge battery down to "too weak to vape" and you reach for your spare batteries. When I am using a mech, I use the Ohm's Law calculator to find the applied watts at full charge volts of 4.2, and then the applied watts at the "change your batteries" voltage of 3.5, and apply those two wattage values to the heat flux section of Steam Engine to get an idea of how much and how hot a vape will be coming off my coils. I often find this causes me to re-think my builds a bit before I actually build them.
To give you an example; I recently got a Dark Horse dripper. I wanted to use it on a one-battery mech-- a Smok Magneto V1 tube mod-- which uses the same "4.2V and 10A" restrictions we discussed last night for one battery. Knowing I could not build below .42, that's where I started. I set Steam Engine up for dual slick wire parallel coils, 28ga Kanthal A1 and .45 ohms on a 3mm mandrel. That all worked out, but when I put the maximum full charge watts of 42 in the heat flux section I was way up in the red zone, putting nearly 300 mW/mm^2 on the wire. This would have been a scalding hot vape (to me, some people like it) and might have burnt my juice so it tasted nasty. So I backed off of it. I eventually worked my way out to a .6 ohm coil on a 2mm mandrel-- I did all this before twisting one piece of wire-- to give me heat fluxes between 185 to 135 mW/mm^2 from full charge to depleted. Then I built that coil and installed it. It measured out to be .66 Ohms and it makes enough flavor to make your eyes water and blows enough steam to fill a room with 2 or 3 puffs-- and all that on a one-battery mech at no more than 25 watts.
If you're a cloud chaser-- I suspect you are, those are the dudes who use series mech mods-- fine: the more watts you can put on the coil, the bigger you can chuck, all other things being equal. And all this is a little overwhelming at first, as I clearly understand. It was to me, too, and I already understood ohms law before I started vaping. What I am saying is, as you learn more, and grow more confident, there's a lot out there to learn and more to do than merely chucking clouds. So have fun and enjoy the journey. Above all stay safe and, once you have built your safety fence you always stay inside, start experimenting. Mech mods-- I love them-- are harder and more challenging to do than regulated mods. And they are also more satisfying when you learn how to make one do what you want. Any idiot can build any old coil and set the wattage at 27 to see what they get. Building a mech to yield the same 27 watts while still giving you the vape you want is a different matter, and a lot more fun when you get there. You just have to keep your chin up through repeated failures until you *do* get there
Great lecture for EE201 and ME201
Maybe age and experience helped me understand it all this time, better than I did 30 years ago! 
If you are having your batteries connected in PARALLEL then your total output voltage is still going to be only 4.2v........ If on the other hand, you have your batteries connected in series, then the voltages add to each other to give a total output voltage of 8.4 volts applied to the coils.
You're right, of course, but he's not, or not according to the website. The Dimitri is a series mod...
(bows)Great lecture for EE201 and ME201
Well, I have to say age and experience have been a help to me...
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