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Series Battery Question

So, I picked up a Noisy Cricket yesterday and was just wondering, it being a series mod, does the voltage double (so 7.4V vs 3.7V) or is it singular between both batteries? I'm fairly certain it is combined, but not certain. Running a Fishbone RDA with a res of 0.4Ω, and it feels like it ramps up far faster than I'm used to (65W is what I run on my X Cube II with a 0.15Ω build). This is my first dual 18650 mech mod ever went straight from single 18650 mechs to series VV/VW boxes.
 

robot zombie

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Member For 4 Years
Worth mentioning that with double-voltage comes double-current and therefor quadruple-wattage.

Let's assume you're running that build on a single-battery mech mod with a fresh battery and minimal drop/sag (3.9v.) That's gonna draw ~10A to give you 38w. Drop the same one on the NC, again assuming minimal drop (7.8v.) Now we're looking at a draw of ~20A that yields 152w.
 
Worth mentioning that with double-voltage comes double-current and therefor quadruple-wattage.

Let's assume you're running that build on a single-battery mech mod with a fresh battery and minimal drop/sag (3.9v.) That's gonna draw ~10A to give you 38w. Drop the same one on the NC, again assuming minimal drop (7.8v.) Now we're looking at a draw of ~20A that yields 152w.

Yup. I've got 3.7V batteries. Figured it to be about 138W, roughly. Trying to think of a good build that will run at about 50-75W,since that's what I run my VV/VW boxes at. I've got 24g and 30g kanthal right now, I wrap with a 2.5mm-3mm driver. Any suggestions?
 

Mythical_OD

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Member For 4 Years
Im gonna ask here instead of making a new thread about it, since it follows the Noisy Cricket theme:

So I have a NC showing up soon, its my first Series mech, and Im wondering (since RZs post has me questioning it now) if I go on the steam engines ohms law calculator and punch in the variables if thats gonna be the true numbers, or if theres more at play with a series mod.

Example. Just assuming 7.4 volts and a 0.7 ohm build, it comes out with about 78 watts at 10.5 amps. Are those gonna be realistic numbers, or is something getting multiplied somewhere?

And I assume with a series mod pushing that much power through to the coils youd want to have some beefy builds in there, no? Like, you probably wouldnt want to use 28 or 30 gauge micro coils on there right?
 

robot zombie

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Yup. I've got 3.7V batteries. Figured it to be about 138W, roughly. Trying to think of a good build that will run at about 50-75W,since that's what I run my VV/VW boxes at. I've got 24g and 30g kanthal right now, I wrap with a 2.5mm-3mm driver. Any suggestions?
Hmm, with the 24g, 75w is impractical on the cricket... ...for duals, anyway. A single 12-14 wrap 24g may not be too bad. They'll put you in the ballpark of 75-90 watts.

You could try twisting 2-4 strands of the 30g and shooting for .6-1 ohm duals

I dunno, you may want to pick up some 26 and 28 if you're really set on that wattage. I would also suggest you try claptons with those guages. They work exceptionally well at the mid/mid-high sub-ohm, which isn't a ridiculously high-power/high-mass range.

But what I really want to stress here (and meant to highlight when I mentioned the power difference between series and single/parallel) is that when you're running series, the power/surface area balance is different, meaning that the wattage and coils you're used to may not align with what ultimately gives a comparable experience on the cricket. The sweet spots are different.

if I go on the steam engines ohms law calculator and punch in the variables if thats gonna be the true numbers,
Yes. Give it a try. Plug in any set of variables you want and note the wattage. Now, double the voltage. You will see that the current has doubled and thus the wattage quadruples. The numbers will reflect that.

And I assume with a series mod pushing that much power through to the coils youd want to have some beefy builds in there, no? Like, you probably wouldn't want to use 28 or 30 gauge micro coils on there right?
Mhm... ...well, typically, though not necessarily. It's about how you balance the power. The coils don't have to be beefy depending on how much power they pull for their surface area. Claptons, for instance can be smaller because they pull less power per square mm. It's not about how big they are overall, but rather about how much current they draw for how big they are.

This also applies to coils wrapped with thinner wire. You absolutely can use 28g or even 30g micro coils if you want. You will still want to do more wraps than you would otherwise, but they don't have to be extremely big to give you a fairly cool, wet, flavorful vape. A 13-wrap, 2mm dual 30g, at 1.5 ohms, would only get around 38w, so it wouldn't be a very warm vape, though it would still have a fast ramp-up. That's not exactly a monster build, either. You could do the same build with 28g and even at 1 ohm, it's only pulling 50 odd watts to pretty average-sized coils.

Another thing worth noting. Bigger coils wrapped with fatter wire retain more heat, so even if you manage to do a monster build big enough AND low-resistance enough to give the heat somewhere to go and still keep the ramp-up reasonable, it will quickly start to overheat as you vape on it, as it'll be heating up much faster than it's cooling down. You need a lot of airflow and chamber space to keep it at vapable temps, not to mention wicking properly.

Smaller coils that pull less power don't have the mass to hold onto as much heat, though with 7 odd volts going to them, you can still have relatively high-surface-area (though still considerably smaller) coils that heat up quickly and yet provide what is at most, a somewhat warm, but still very dense and flavorful vape with more normal wicking/airflow demands.

Again, there's more than one way to balance the voltage. You can either add mass for a given current level or reduce current for a given mass. Just some food for thought. If you want a cooler vape, lower gauges are very viable. 26g and 28g work very well for this, while pretty much anything practical with 24g is going to be pretty hot. Sounds counterintuitive, but that's just how the power/heat-flux/heat-capacity ratios play-out in series.


I'm actually running .67 dual 38/28 claptons on mine. Not beefy at all - they're 8 wraps on a 2.5mm bit. It's still very much vapable and in fact, one of my favorite shorty builds. It's a snappy, warm, textured, flavorful vape with pretty damned solid vapor production for its size. It doesn't need even as much airflow as say, a .18 dual 24g on a tube mod would like.

Realistically, we're looking at about 80w going to those coils - a good balance for the surface-area, which isn't too substantial. Another build I like to do is a .7(ish) dual 38/28 clapton... ...8 wraps @ 2mm, so it is very much a micro build, but it's not unbearably hot. At 10 wraps, it would barely be warm, yet still rather small.


I'd like to suggest that both of you try using the heat flux calculator in steam engine to see how different factors affect the power/surface-area ratio. Just hop over to the battery drain calculator and plug in a target resistance, calculate the wattage for the build at 7.4v-.7.7v, plug that into the heat flux calculator back over on the coil calculator, punch in that target resistance, and start playing with guages, diameters, and configurations to see how much heat the coil will generate and how fast it will heat up.

Also note the heat capacity. It can be much higher than usual since you're working with so much voltage, but you can still use it to pit different coils meant for series against one another. You could also try plugging in builds you like on other devices and comparing the flux/capacity of those to your theoretical series builds. This should help give you an idea of how to balance out your power and surface area for series.

You get a feel for the implications after you do a few builds, but that'll hopefully give you guys a better idea of where to start.
 
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Mythical_OD

Gold Contributor
Member For 4 Years
lol officially confused. Electrical shit has always been a weak point for me.

Ill try some different stuff out. Ive got a shit load of VTC4s to use, so Ill pop those in there and keep it under 25amps and see what I come up with. Ive got a bunch of different wire from claptons, fused claptons, hive, dual and quad twisted, etc. to play with so Ill get something thats decent. I just wanted to make sure the steam engine ohm law calculators numbers were still accurate for a series mod since Im electrically retarded (awesome name for a band) lol.
 

robot zombie

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lol officially confused. Electrical shit has always been a weak point for me.

Ill try some different stuff out. Ive got a shit load of VTC4s to use, so Ill pop those in there and keep it under 25amps and see what I come up with. Ive got a bunch of different wire from claptons, fused claptons, hive, dual and quad twisted, etc. to play with so Ill get something thats decent. I just wanted to make sure the steam engine ohm law calculators numbers were still accurate for a series mod since Im electrically retarded (awesome name for a band) lol.
Haha, alright, check it out... ...the coil doesn't have to be huge if the resistance is higher compared to its mass. That's basically it. You can do smaller, high resistance coils (as in, thin wire with high wrap-count.) Since it's getting a lot more voltage than your standard mech would give it, you can pack in a pretty respectable amount of surface-area without resorting to monster coils with thick wire and have a cooler, faster vape.

The point was that you don't have to build big coils... ...you can also use thin wire to reach higher resistances with smaller builds. It works better in series than it tends to on standard mechs because the sweet spot in resistance is higher, so they're larger (though they're still small by series standards.)

Like, say you wanted to do a dual 28g on a standard voltage mech mod. The resistance would be pretty high for a mech, but it wouldn't give you much flavor or vapor because it's so tiny at the optimal power range, whereas you can double the resistance for series and have a vape with similar temp/ramp profile, but essentially double the vapor and flavor. It would be comparable to a dual 24g at its 4v sweet spot.

Or you can clapton, which adds mass without changing the amount of power the coil gets. Same effect.

Nother thing worth mentioning, I think you'll find 25 amps is more than you will need. A .3 draws 25 amps... ...and also gives you almost 200 watts! You would really have to build something crazy to handle that. Probably a 25mm rda at the smallest too. Most anything that generates that kind of wattage is going to be big and give off a ton of heat.
 
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Mythical_OD

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Member For 4 Years
Ok I think I see what your sayin. Basically you can up the resistance on a series mod and get the same effect as building low on a parallel mod because theres more power going through. Got it.

For my first build Ill probably use the 26/32 clapton wire I have. See where that gets me. Above all I just want to stay safe. The hybrid cap is gonna take some getting used to in terms of what I use. Fortunately I have a lot of RDAs so I almost certainly have a couple at least that will work properly on it.
 

Mythical_OD

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Member For 4 Years
Oh and Ill almost certainly not even touch 25 amps. I was just using that as kind of the ceiling for the batteries Im using. They technically are rated at 30 amps, but I like keeping a nice buffer just to be safe.
 

robot zombie

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Member For 4 Years
Ok I think I see what your sayin. Basically you can up the resistance on a series mod and get the same effect as building low on a parallel mod because theres more power going through. Got it.
Exactly. :cool: You can and should use different gauges and resistances to get the same power/size ratios that you're used to.

Have fun with the cricket and the builds you can do with it! Once you get a feel for it, it's difficult to use anything else.

For my first build Ill probably use the 26/32 clapton wire I have. See where that gets me. Above all I just want to stay safe. The hybrid cap is gonna take some getting used to in terms of what I use. Fortunately I have a lot of RDAs so I almost certainly have a couple at least that will work properly on it.
Most RDA's these days will work safely with it. A 1mm protrusion is enough. Just beware of adjustable pins. It's better to have one that naturally protrudes at 1mm or more than it is to have to back the pin out that far. May want to put some electrical tape on the battery contacts and screw it down a few times to make sure that an adjustable 510 isn't gonna migrate over time.

One neat thing I've noticed about the hybrid topper on the cricket. As long as that little insulator ring is intact, the length of most 510's isn't enough for the negative to ever make contact with the battery, even if the positive pin is recessed. I have some atties with 510 pins that won't fire at all even though they do protrude past the negative. The insulator will stop the battery from reaching it at all. Wouldn't trust that to always (or really ever) be the case... ...just thought it was interesting.

With a standardized length for the threaded portion of all 510's, all hybrid mods could be made to be short-proof with any atty. You could easily design the topper to never touch the negative of any atty. Wouldn't matter if the pin was adjustable, spring-loaded, or flush. At worst, an incompatible atty just wouldn't fire.
 
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Mythical_OD

Gold Contributor
Member For 4 Years
So talking about 510s, which is negative and positive? Is the center pin the positive and the outside the negative? I probably should get more informed on this shit before I ordered a hybrid topped mech lmao. But thats how I am, I wait until I have to do something to do it.
 

robot zombie

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Member For 4 Years
So talking about 510s, which is negative and positive? Is the center pin the positive and the outside the negative? I probably should get more informed on this shit before I ordered a hybrid topped mech lmao. But thats how I am, I wait until I have to do something to do it.
You've got it. The pin that runs to the center post is the positive. The threaded part and the rest of the deck is the negative.
 

suprtrkr

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Double volts, and don't coil it below .5 ohms on 20A batteries. That draws 16+ amps, leaving very little safety margin. Your .42 coil draws 20A on fresh batteries, leaving no margin at all. This shouldn't be a problem; a .5 coil makes 140+ watts.
 
Double volts, and don't coil it below .5 ohms on 20A batteries. That draws 16+ amps, leaving very little safety margin. Your .42 coil draws 20A on fresh batteries, leaving no margin at all. This shouldn't be a problem; a .5 coil makes 140+ watts.
35A batteries, plenty fine there. As far as the 0.5Ω minimum, well I'm using 35A batteries (actually going to re-test them to make sure they're still performing at 30+A as they're older). The mod recommends nothing lower than 0.25Ω, which I can easily avoid.


I've always been a dual coil guy, can't say I've ever run a single coil when the RDA/RTA could fit two, but I've also never had an RDA that would fit 10+ wraps easily on the deck. I'm thinking about getting a Dotmod Petri 2 (or comprable dual post, I hate the tri-post on my Doge X2) because of the dual post deck, should be easier to cram a wider coil in there. I'm going to play with some stuff today on my Mutation X V4 after I go pick up a few lengths of kanthal and see what I can't break ;) Thanks for the tips, skimmed the bulk of the post, but I think I understand a little better.
 

suprtrkr

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35A batteries, plenty fine there. As far as the 0.5Ω minimum, well I'm using 35A batteries (actually going to re-test them to make sure they're still performing at 30+A as they're older). The mod recommends nothing lower than 0.25Ω, which I can easily avoid.
Good luck. By the way, there is no such thing as a 35A battery in 18650 size, so far as I am aware, no matter what it says on the label.
 

Mythical_OD

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Member For 4 Years
True. The VTC4s are 30A CDR and legit as far as I know those are the only ones at 30 even, the ones sayin 35 are reading the pulse discharge rate.
 

robot zombie

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True. The VTC4s are 30A CDR and legit as far as I know those are the only ones at 30 even, the ones sayin 35 are reading the pulse discharge rate.
In real-life, they barely qualify as true 30A batteries. In the past, they have been tested and found to get a touch too hot to bear the "30A" CDR. It's probably best to just treat them as "20A+" cells. You can safely run them up to 25A-30A and they are indeed one of the better options for that kind of discharge, but you will still be taxing them significantly in doing so.

As martnargh said, there are true 30A cells... ...some can even surpass that safely, though the voltage sag and short runtime don't make them very useful outside of say, all-mechanical cloud comps. The LG HB4, for instance, is a 30A battery that takes 35A pulses like a champ. No damage and actually very low temperature. The voltage sag is atrocious and the runtime suffers accordingly, but they can do it!

I really don't get the 30A obsession. It's just needless with all of these dual 18650 series and parallel regulated and unregulated mods out there. Even the best 30A batteries aren't performing optimally at that point. The run-time always sucks and they don't tend to hit very hard a 30A. The chemistry is not there for single 18650's right now. There are limits to how far we can go with the current tech at that form factor. Just because you can safely max your current with a certain battery doesn't mean that you're making the best use of it.

My general philosophy with batteries is this. Don't use them for all that they can do. The idea is to let them do what they do best... ...not compared to other batteries, but within the range of their own capabilities. Give them a chance to work well and they will.

I honestly do believe that for vaping, you're better off using really good 20A batteries and running them within what they're rated for. You will get much better performance that way. This is especially true with a mod like the cricket, which doesn't need a lot of current to hit a high wattage level. Part of the reason it hits so hard is that it's not demanding as much current from the batteries to give you the power. It's not just that the native voltage is higher... ...the voltage sag is also reduced.

I'm not tryin to step on anyone's steez, here. If you like your 25A or higher vape, you know what you're doing, and you're taking the proper precautions. Just some observations on what seems to get me the best results... ...don't get me wrong, I have my shits and giggles moments with current, but generally, it's not the most practical or optimal way to get what yer after.
 
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mike.o.13

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Up until recently everything I vaped was on regulated built in battery mods. I have been using a duel 18650 regulated mod but have been thinking about getting a mech. Anyone have any links or videos on series builds and the like?

Sent from my SM-G360T using Tapatalk
 

JERUS

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Up until recently everything I vaped was on regulated built in battery mods. I have been using a duel 18650 regulated mod but have been thinking about getting a mech. Anyone have any links or videos on series builds and the like?

Sent from my SM-G360T using Tapatalk
Some talk about it in here:
http://vapingunderground.com/threads/thoughts-on-the-noisy-cricket.157210/

Main thing is to remember to do your math. You'll want higher resistance than what you might normally use. .42Ω is going to be your downward limit for 20amp cells. After that it's a lot of tweaking and tuning until you find what's just right for you.
 

Mythical_OD

Gold Contributor
Member For 4 Years
I think I said it before, but I dont really run my batteries up to 25 or 30 amps ever. I just buy VTC4s because they technically can handle that amount. Generally, if Im building some coils and Im checking where they fall in ohms law, Im trying to not go too much over 20 and its rare that I even go there. Its more for the extra headroom just in case something wild happens. Like if for some weird reason my coils that were reading a .2 and running within the 20 amps suddenly pop and settle and start reading .1 or lower or something and going well over the 20amp limit. In that event, having the extra 10 amp headroom could mean the difference between batteries venting and batteries just getting a little warm.
 
Good luck. By the way, there is no such thing as a 35A battery in 18650 size, so far as I am aware, no matter what it says on the label.
Tested with an average discharge of just under 30A (as I did say I would test them). Either way, I'm well within safety constraints. I've also never pushed more than 25A through the cells, which even more so reinforces the fact that I'm well within my safety constraints.
 

martnargh

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In real-life, they barely qualify as true 30A batteries. In the past, they have been tested and found to get a touch too hot to bear the "30A" CDR. It's probably best to just treat them as "20A+" cells. You can safely run them up to 25A-30A and they are indeed one of the better options for that kind of discharge, but you will still be taxing them significantly in doing so.

As martnargh said, there are true 30A cells... ...some can even surpass that safely, though the voltage sag and short runtime don't make them very useful outside of say, all-mechanical cloud comps. The LG HB4, for instance, is a 30A battery that takes 35A pulses like a champ. No damage and actually very low temperature. The voltage sag is atrocious and the runtime suffers accordingly, but they can do it!

I really don't get the 30A obsession. It's just needless with all of these dual 18650 series and parallel regulated and unregulated mods out there. Even the best 30A batteries aren't performing optimally at that point. The run-time always sucks and they don't tend to hit very hard a 30A. The chemistry is not there for single 18650's right now. There are limits to how far we can go with the current tech at that form factor. Just because you can safely max your current with a certain battery doesn't mean that you're making the best use of it.

My general philosophy with batteries is this. Don't use them for all that they can do. The idea is to let them do what they do best... ...not compared to other batteries, but within the range of their own capabilities. Give them a chance to work well and they will.

I honestly do believe that for vaping, you're better off using really good 20A batteries and running them within what they're rated for. You will get much better performance that way. This is especially true with a mod like the cricket, which doesn't need a lot of current to hit a high wattage level. Part of the reason it hits so hard is that it's not demanding as much current from the batteries to give you the power. It's not just that the native voltage is higher... ...the voltage sag is also reduced.

I'm not tryin to step on anyone's steez, here. If you like your 25A or higher vape, you know what you're doing, and you're taking the proper precautions. Just some observations on what seems to get me the best results... ...don't get me wrong, I have my shits and giggles moments with current, but generally, it's not the most practical or optimal way to get what yer after.
I agree to a certain extent.
I cant speak for everyone but the reason I need extra high drain cells (ie. 30a cells) is because i prefer the vape experience a mech provides over regulated and also i enjou a hotter than average vape. On the cricket the max ive gone and it still being pleasurable is .39, on parallel im into .08-.12.... hot vape.
Its been my experience for a couple years vtc4s are the only cells that can hand with that kinda fire.
Whether mooch tested em lower than 30a or not its still my experience that i can hit em low and theyve never really gotten hot on me.
Hb6s suck ass..... after 15 mins of vaping you hit a big ass downer of power. Theyre good for compa as you said. But even that most of the go to cells the compers i see use vtc3s...
So while keeping it at .2-.3 or more is ok for some people for me its noy a good vape and i gotta tale 20nsecond drags just to get something out of em.
If i had no other option, id get me more hbs and rock those...

Sent from my SM-N920T using Tapatalk
 

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