Why would anyone use a series mod?

[sonicbomb]

Yeah, electrically it's poor practice to expect to drive .1 ohm or whatever. It only takes a few hundredths extra in there to totally mess things up. And if I take a regular ohmmeter that costs hundreds of dollars and measure the coil, the probe contact resistances can easily swamp the result (up to .3Ω).

The discussion above talks of mass. Surface area is the primary determiner of power capability, given adequate wicking and air it says how much juice it can be in contact with and therefore the long-term power handling. Mass merely slows it getting there. The advantage of using more voltage is a coil with LESS mass tends to result. A wire twice as thick has twice the surface area and *four times* the mass, so even if only half as long has twice the mass, twice the heatup time. Now, there are times the heatup time could increase when using a longer piece of thinner wire, but if so either the power has been decreased due to resistance, and/or it's actually a bigger coil but for some other reason the power can't actually be increased because the coil wasn't the limit.

You had me at electrically...

This article is a great reference read that helped me set a few things straight, and this one on heatflux.

 

[OldBatty]

Tfv4 octuple coils

Is that "dual three-phase" wired delta or wye?

Even us tootle puffers are not immune to the 'double the voltage, quadruple the watts' problem. 1.6 ohm contact coil, 30 gage kanthal, about six wraps on a 1/16" rod, rayon wick... Vapes fine with a single battery, instant burnt wick on a dual. Was hoping for throat hit and clouds

 

[KenD]

Hey everybody.

I just want to apologize upfront. I am sure this has been talked about, and I searched and read a lot of threads about series mods, but I couldn't find the answer I was looking for, so I started this thread.

Ok, to my question/point: I don't understand what purpose a series mod serves. Here is my thinking.

Let's say I wanted to vape at the SMOK TFV12 tank. Obviously I want some clouds. The coils for the tank that are rated in the 120-200w range are .12ohm coils. The coils state that they can be vaped as high as 350 watts. Cool.

So, let's say I threw that on a single or parallel unregulated mod, with freshly charged batteries. I would be vaping at 147w (from ohm's law V = iR and P=Vi, 4.2v/.12ohms = 35 amps, x 4.2V = 147w). Not bad, this is probably very satisfying. If I threw that on a dual battery series mod, however, I would be vaping at 588w!!! (same math as before, but with 8.4v) Obviously, I do not want to vape a tank rated for 350w max at 588w. I might not even want to vape it at 350 once I try it lol.

So let'ts try to go by the power level I am vaping at then. Say I want to replicate the 147w I would be vaping at on a freshly charged series mod. 147w/8.4v = 17.5 amps. At first glance, this seems like it would be better for my batteries and lead to longer battery life for the same power vape, since I am drawing less amps. The thing is, I would need a .48ohm coil to achieve this.

My question is, why the hell would I want to vape a .48ohm coil at the same power level as .12 ohm coil? Wouldn't that burn the crap out my coil and make it taste nasty?

And that is basically what I am getting at. On a series mod, you need to use a much higher resistance build to vape at the same power levels, which I cannot understand why I would want to do that. For example, if that tank had .48 ohm coils available, I imagine they would be rated for something like 20 - 50w.

Are these wattage ratings based on the voltage an amperage contributing to the power level? Is a watt not always a watt? I also feel like the .48ohm coil would be much smaller than the .12 ohm coil anyway, so it would have less surface are and therefore vape less juice at any one particular moment.

What am I missing here? Are you supposed to take much shorter drags on a series mod, so that the vape doesn't taste like burnt coil? Wouldn't this still result in less vaper? I have played around with raising the watts and taking shorter drags on my regulated mods (which I believe provides the same experience as vaping single/parallel vs. series, that is, only if a watt = a watt regardless of the voltage and amperage), and I find that using the typical power level for a coil and taking longer drags provides better clouds and taste. Is that just it, that it's all subjective whether you prefer shorter or longer drags?

Am I understanding this right? I see how vaping at the same power levels would essentially make the battery life equal when considering puffs taken, but I am just not understanding why you would ever want to vape higher resistance coils at the same wattage levels as lower resistance ones. Can someone please help me understand? Thank you!

A couple of points.

With regulated mods the resistance of the coil doesn't adjust the wattage. 147w is 147w with both a .12 and a .48 coil (assuming that the mod can deliver the needed voltage).

The amp draw on regulated mods is calculated differently than the draw with mech mods. You don't use ohms law but rather watts law.

Almost all current multiple-battery regulated mods are series rather than parallel. In a series setup the available battery voltage is higher which means that boosting the voltage going to the coil is (rarely) needed. As bucking is more efficient than boosting a series setup will, in theory, give you a bit more battery life. The battery sag will be more noticeable in a parallel setup as the boost needs to increase as the charge decreases. Conversely, in a series setup you're moving towards the actual battery voltage, meaning that the regulator actually has to do less work.

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[PBody19]

A couple of points.

With regulated mods the resistance of the coil doesn't adjust the wattage. 147w is 147w with both a .12 and a .48 coil (assuming that the mod can deliver the needed voltage).

The amp draw on regulated mods is calculated differently than the draw with mech mods. You don't use ohms law but rather watts law.

Almost all current multiple-battery regulated mods are series rather than parallel. In a series setup the available battery voltage is higher which means that boosting the voltage going to the coil is (rarely) needed. As bucking is more efficient than boosting a series setup will, in theory, give you a bit more battery life. The battery sag will be more noticeable in a parallel setup as the boost needs to increase as the charge decreases. Conversely, in a series setup you're moving towards the actual battery voltage, meaning that the regulator actually has to do less work.

Sent from my K6000 Pro using

Yes. I only brought up regulated mods to say I could simulate what it would be like to take a coil built well for a single battery (or parallel) mech mod, and put it on a series mod. The example of a TFV12 coil is bad for a few reasons. I only used that because I wanted an example of a coil at a particular resistance know to be good for a particular wattage range.

Say I had a a dual coil .12 ohm build, some fancy coils like alien claptons good for 147w (or whatever you want, this is just an example for the idea of all this) ona single battery mech mod. If i take those coils and put them in an atty that allows for a series build, now I have a .48 coil that will be good for 147w on a series mech mod. I am looking at it from the common sense angle that, well, since its the same damn coil, you would still throw the same watts at it. But from a scientific perspective, with what I have learned from reading this thread, I believe the terminology would be "the heat flux" is the same? Yea?

 

[KenD]

Yes. I only brought up regulated mods to say I could simulate what it would be like to take a coil built well for a single battery (or parallel) mech mod, and put it on a series mod. The example of a TFV12 coil is bad for a few reasons. I only used that because I wanted an example of a coil at a particular resistance know to be good for a particular wattage range.

Say I had a a dual coil .12 ohm build, some fancy coils like alien claptons good for 147w (or whatever you want, this is just an example for the idea of all this) ona single battery mech mod. If i take those coils and put them in an atty that allows for a series build, now I have a .48 coil that will be good for 147w on a series mech mod. I am looking at it from the common sense angle that, well, since its the same damn coil, you would still throw the same watts at it. But from a scientific perspective, with what I have learned from reading this thread, I believe the terminology would be "the heat flux" is the same? Yea?

Well, .12Ω will exceed the cdr of any single battery. Just a bad, bad idea. A .48Ω coil on a series mech though would be ok for even 20-amp batteries. In theory you could build a coil that would be fully useable at 147w. For example, a 22 ga dual coil in series would have 7-8 wraps (3 mm id) and a heat flux of 347 at the full 8.4v. Hot but doable, and the voltage sag would likely bring that to a more comfortable level. At the nominal charge, where you'll be for most of the battery time anyway, the heat flux is very comfortable. Complex coils should handle it even better I think. Not the way I would vape, but possible.

On a mech mod you need to build your coils for your intended use, and that takes more than simply calculating the wattage. Heat flux is definitely an important factor to consider, but ramp up due to coil mass and many other factors as well. It's a long time since I built for mechs and I wasn't really interested in other than simple single- and dual coil builds back then, all at more than .5Ω (often way higher than that).

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[PBody19]

Well, .12Ω will exceed the cdr of any single battery. Just a bad, bad idea. A .48Ω coil on a series mech though would be ok for even 20-amp batteries. In theory you could build a coil that would be fully useable at 147w. For example, a 22 ga dual coil in series would have 7-8 wraps (3 mm id) and a heat flux of 347 at the full 8.4v. Hot but doable, and the voltage sag would likely bring that to a more comfortable level. At the nominal charge, where you'll be for most of the battery time anyway, the heat flux is very comfortable. Complex coils should handle it even better I think. Not the way I would vape, but possible.

On a mech mod you need to build your coils for your intended use, and that takes more than simply calculating the wattage. Heat flux is definitely an important factor to consider, but ramp up due to coil mass and many other factors as well. It's a long time since I built for mechs and I wasn't really interested in other than simple single- and dual coil builds back then, all at more than .5Ω (often way higher than that).

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I hear you on exceeding the CDR not being wise. From a different thread of mine that you posted on, I think you know how I feel about CDR lol. But in this case, a "bad, bad" idea? Meh 35 amps at 147 watts. How long could your puffs last anyway at that wattage? How many hist could you get with an HB6 before youre very near its CDR (taking voltage under load into account and all)? It's not such a satisfying zone in this scenario, lol, but it's pretty safe, especially if youre not chain vaping.

 

[kbeam418]

I hear you on exceeding the CDR not being wise. From a different thread of mine that you posted on, I think you know how I feel about CDR lol. But in this case, a "bad, bad" idea? Meh 35 amps at 147 watts. How long could your puffs last anyway at that wattage? How many hist could you get with an HB6 before youre very near its CDR (taking voltage under load into account and all)? It's not such a satisfying zone in this scenario, lol, but it's pretty safe, especially if youre not chain vaping.

It's safe until something breaks and you're relying on that pulse rating . I use Mooch's "max vaping amps" but, not to sound like a know it all, I know quite a bit about batteries and have basic electrical knowledge. I don't recommend exceeding Mooch's recommendations EVER! If something can go wrong it will go wrong and with lithium batteries they don't fail nicely.

 

[PBody19]

It's safe until something breaks and you're relying on that pulse rating . I use Mooch's "max vaping amps" but, not to sound like a know it all, I know quite a bit about batteries and have basic electrical knowledge. I don't recommend exceeding Mooch's recommendations EVER! If something can go wrong it will go wrong and with lithium batteries they don't fail nicely.

In this example, we would be pulsing the HB6 battery for 2 seconds or less, only a few times, at a current draw no more than 3 amps above mooches CDR rating.

 

[kbeam418]

In this example, we would be pulsing the HB6 battery for 2 seconds or less, only a few times, at a current draw no more than 3 amps above mooches CDR rating.

Above the cdr or above the mva? If you go above mva (that's 40 amps for the HB6) you're not vaping safely.

 

[PBody19]

Above the cdr or above the mva? If you go above mva (that's 40 amps for the HB6) you're not vaping safely.

CDR