Help understanding 2 different coils

[CloudMasta69]

Hello fellow gentlemen!

Im fairly new to mech mods and I have ran into a bit of problem.

So im using a dual 21700 stacked mech mod(series obv) and I was using dual coils that was built for me that together were a total of 0.3 ohms. They are good and produce alot of smoke but i dont get to puff for longer than maybe half a second before it gets too hot and eventually burns.

I decided to go out and buy higher ohm coils that would allow me to at least feel like im drawing a bit longer and some taste.

I wanted 0.6ohms which seemed just about right for me. Unknown for me at the time was that buying two 0.6ohm coils and using them would result in a 0.3 ohms which puts
me right back to basically the same resistence as my old coils.
Knowing that I was like ”eh whatever, at least I got some brand new coils now” right.

But then i ran into another problem when firing the new coils up… It heated up so so quickly that it just split off the rda and melted! … but that was also a 0.3ohm so how could that happen??

Note that the new 0.3 coils were alot thinner than the other 0.3 coils that seemed to contain the heat better than the new ones and im just wondering why that is?

If the case is that the size of them matter BUT both of them are at 0.3 ohms.. then why would ohms matter at all? Why dont we measure the coils by their size if 2 of the same ohm coils with different thickness and size conduct heat differently?

CAN SOMEBODY PLEASE ANSWER THIS QUESTION because it literally drives me crazy!

I’ll also upload a picture of them
(the thicker one = 0.3 ohms dual)
(the thinner one = 0.3 ohms dual)

 

[Deleted member 54254]

Using series mechs is not for the inexperienced, you should be able to answer this question yourself, have a read through the relevant parts of the forum.

 

[Crispycritters]

Essentially - because many users who prefer series mech mods like high power levels the professionally made 'series coils' tend to be low enough in ohms so they won't overstress the batteries but still provide a VERY high wattage vape..

If you use ohms law and figure out what 8.4 Volts divided by 0.30 Ohm is you will come up with 28. Which means they will pull 28 Amps of current so you will be safe with a pair of good 21700 Batteries like the 30 Amp Molicel P42s or 35 Amp Samsung 30Ts.

Unfortunately to figure out the watts you will be vaping at you multiply the Amps by the Voltage. In this case 28 x 8.4 = 235.2. In reality there will be some inevitable voltage drop so in reality you will be getting something like a 200 Watt Vape.

The reason you find the vape OK for half a second but then unbearably hot is that the coils will take half a second to heat up - once they do reach temperature they will be HOT.

You are on the right track by assuming you need to go higher in resistance to get a cooler vape that is more manageable, I suggest you start with a 0.60 ohm build as this will be approximately half the wattage of the 0.30 ohm coils you found too hot. The problem you may experience is actually finding coils that are 1.20 ohms that aren't pissy little things designed for MTL. The second pair of coils you bought may be the same resistance as the first pair, but they have insufficient mass to cope with such high power - that is one reason they didn't last, the other is you probably tried to be them in by throwing the full power of your mech at them, which is too much too soon. What I suggest is you buy a spool of premade Ni80 26/36 gauge Clapton Wire and make two nine wrap coils around a 3mm internal diameter coiling rod. This will give you a pair of coils that together will work out in the 0.60 ohms ballpark, but are large enough to cope with 8.4 volts from the batteries. Any pair of 1.2 ohm coils WON'T work and piddly sized MTL coils will just pop instantly.

The only other problem you will have then is you need to glow the coils and strum out hot spots - and you really DON'T want to do this on your mech as you don't need to glow them at full power (if you do any hot spots may cause the coils to melt and pop - as you have already found to your expense) - so you need a dual battery regulated mod to glow them on, normally people use build tabs for this but when it comes to large high ohm coils single 18650 build tabs simply can't provide high enough power so I really think you ought to save your money and spend it on a suitable mod rather than a build tab that will be incapable of giving any more than about 4 Volts max.

If you don't understand what I have written I recommend you put your mech mod away, and buy a regulated mod if you don't already have one (dual battery if possible so it can be used later to bed in coils for your series mech when you decide you have acquired the knowledge to use it safely).

Sorry bud, but mech mods aren't forgiving and accidents can turn nasty fast. Until you are confident you know what you are doing, put it away until you have done some research. Better safe than sorry.

 

[CloudMasta69]

Essentially - because many users who prefer series mech mods like high power levels the professionally made 'series coils' tend to be low enough in ohms so they won't overstress the batteries but still provide a VERY high wattage vape..

If you use ohms law and figure out what 8.4 Volts divided by 0.30 Ohm is you will come up with 28. Which means they will pull 28 Amps of current so you will be safe with a pair of good 21700 Batteries like the 30 Amp Molicel P42s or 35 Amp Samsung 30Ts.

Unfortunately to figure out the watts you will be vaping at you multiply the Amps by the Voltage. In this case 28 x 8.4 = 235.2. In reality there will be some inevitable voltage drop so in reality you will be getting something like a 200 Watt Vape.

The reason you find the vape OK for half a second but then unbearably hot is that the coils will take half a second to heat up - once they do reach temperature they will be HOT.

You are on the right track by assuming you need to go higher in resistance to get a cooler vape that is more manageable, I suggest you start with a 0.60 ohm build as this will be approximately half the wattage of the 0.30 ohm coils you found too hot. The problem you may experience is actually finding coils that are 1.20 ohms that aren't pissy little things designed for MTL. The second pair of coils you bought may be the same resistance as the first pair, but they have insufficient mass to cope with such high power - that is one reason they didn't last, the other is you probably tried to be them in by throwing the full power of your mech at them, which is too much too soon. What I suggest is you buy a spool of premade Ni80 26/36 gauge Clapton Wire and make two nine wrap coils around a 3mm internal diameter coiling rod. This will give you a pair of coils that together will work out in the 0.60 ohms ballpark, but are large enough to cope with 8.4 volts from the batteries. Any pair of 1.2 ohm coils WON'T work and piddly sized MTL coils will just pop instantly.

The only other problem you will have then is you need to glow the coils and strum out hot spots - and you really DON'T want to do this on your mech as you don't need to glow them at full power (if you do any hot spots may cause the coils to melt and pop - as you have already found to your expense) - so you need a dual battery regulated mod to glow them on, normally people use build tabs for this but when it comes to large high ohm coils single 18650 build tabs simply can't provide high enough power so I really think you ought to save your money and spend it on a suitable mod rather than a build tab that will be incapable of giving any more than about 4 Volts max.

If you don't understand what I have written I recommend you put your mech mod away, and buy a regulated mod if you don't already have one (dual battery if possible so it can be used later to bed in coils for your series mech when you decide you have acquired the knowledge to use it safely).

Sorry bud, but mech mods aren't forgiving and accidents can turn nasty fast. Until you are confident you know what you are doing, put it away until you have done some research. Better safe than sorry.

Thank you! This is the exact answer i was looking for! It explains everything and i understans everything you have written!

About the part where the coils need to heat up with a power source not too high.. what i essentially do is i take apart my mech mod and use it with one battery only which it was intended to be used initially(since its a custom 1of1 mod its a dual now) but can be used as a normal single.

Although i still do have my old regulated 220w mod with 18650 batteries and can do it on that one, will the first method essentially be the same since it halves the power? Using samsung 30t for your reference

 

[Mr Ripple]

Thank you! This is the exact answer i was looking for! It explains everything and i understans everything you have written!

About the part where the coils need to heat up with a power source not too high.. what i essentially do is i take apart my mech mod and use it with one battery only which it was intended to be used initially(since its a custom 1of1 mod its a dual now) but can be used as a normal single.

Although i still do have my old regulated 220w mod with 18650 batteries and can do it on that one, will the first method essentially be the same since it halves the power? Using samsung 30t for your reference

No that's not how a mechanical mod works.
Please start finding out how a mech mod works before you carry on using it.
Mech mods can be extremely dangerous if you don't understand how to use them.

 

[Crispycritters]

Thank you! This is the exact answer i was looking for! It explains everything and i understans everything you have written!

About the part where the coils need to heat up with a power source not too high.. what i essentially do is i take apart my mech mod and use it with one battery only which it was intended to be used initially(since its a custom 1of1 mod its a dual now) but can be used as a normal single.

Although i still do have my old regulated 220w mod with 18650 batteries and can do it on that one, will the first method essentially be the same since it halves the power? Using samsung 30t for your reference

No - if you remove one battery you will be getting 4.2 volts max, instead of 8.4 volts.

If you try again with your original 0.30 ohms coils, to use ohms law - 4.2V divided by 0.30 ohms = 14. So they will pull a max of 14 Amps which will not overstress your batteries. However 14 x 4.2 = 58.8 so theoretically you will get a 58.8 Watt Vape, however with voltage drop/battery sag you will probably only get 50 Watts tops.

If you look at my earlier post you will see 8.4V and 0.30 ohms give 200 Watts, but 4.2V will only give 50 Watts. Halving the Voltage does NOT halve the resulting Wattage of the vape. You MUST use Ohms Law to check the resulting current draw from the batteries (Amps) and the resulting Wattage and time you use a different option of Voltage or Resistance to stay safe. Guessing leads to accidents,

Those bulky 0.30 ohm coils you have will take forever to heat up with 50 watts and will give a cold and miserable vape, so that's a no go.

Please don't take chances, put it away until you have sussed ohms law - I recommend you watch Battery Mooch's channel on you tube, the mind your mahs series is essential viewing. I watch it periodically just to refresh my memory even though I feel I am knowledgeable enough to use mechs safely.

Don't buy any more coils until you are confident you know what you are doing, don't assume anything - always check, and always glow your coils on a REGULATED device as the resistance is often much lower than stated until the coils are glowed and bedded in.

Don't chance anything or you may set fire to yourself or your house. Sorry bud, mechs are fcn dangerous in inexperienced hands. Take your time and check EVERYTHING first (including your battery wraps are intact and insulators are in place) before you hit that fire button, or very bad things will happen.

 

[Jd_]

Can i ask a question before he blows up and we r still on this topic? Why would you recommend nichrome instead of kanthal? (Higher resistance, safer glowing, etc)

 

[Deleted member 54254]

I'd put that down to personal preference, I use kanthal on series builds.

 

[Crispycritters]

Can i ask a question before he blows up and we r still on this topic? Why would you recommend nichrome instead of kanthal? (Higher resistance, safer glowing, etc)

Kanthal has higher resistance than Nichrome, so if you are building to a target resistance generally Kanthal coils will be bulkier have more mass than an equivalent Nichrome coil of the same resistance. You could use shorter wire lengths of Kanthal to lower resistance, but this can lead to lower wire to cotton ration and either give insufficient vapour or burn the cotton because you are concentrating the resulting heat in a smaller area, but on a series mech where you need higher resistance Kanthal can be a better option.

Many mech users prefer Nichrome because the ohms remain stable just like Kanthal but tends to heat faster because you are using less metal to get a build of the same resistance.

SS wires have even lower resistance, however when heated the resistance increases (that's why it is good for TC vaping) and maybe less popular for mech builds. If you wanted a dual coil 0.15 build using SS once heated the resistance could jump to 0.17 giving a cooler vape. It can be used, but the resistance isn't stable and if you build lower as you anticipate the resistance will jump you could run into problems.

But one wire isn't superior to another - in many respects it is personal preference

 

[Jd_]

Kanthal has higher resistance than Nichrome, so if you are building to a target resistance generally Kanthal coils will be bulkier have more mass than an equivalent Nichrome coil of the same resistance. You could use shorter wire lengths of Kanthal to lower resistance, but this can lead to lower wire to cotton ration and either give insufficient vapour or burn the cotton because you are concentrating the resulting heat in a smaller area, but on a series mech where you need higher resistance Kanthal can be a better option.

Many mech users prefer Nichrome because the ohms remain stable just like Kanthal but tends to heat faster because you are using less metal to get a build of the same resistance.

SS wires have even lower resistance, however when heated the resistance increases (that's why it is good for TC vaping) and maybe less popular for mech builds. If you wanted a dual coil 0.15 build using SS once heated the resistance could jump to 0.17 giving a cooler vape. It can be used, but the resistance isn't stable and if you build lower as you anticipate the resistance will jump you could run into problems.

But one wire isn't superior to another - in many respects it is personal preference

Oh, yeah, Im aware of different wire properties and such, thats why i was asking.

Thank you tho, now i am even more aware, it was the cotton to wire ratio paragraph that u were referring to