Easy to vent a regulated mod?

[H4X0R46]

Hey guys! So I'm about to purchase my first regulated mod, and I was wondering if it's possible to actually vent one merely by putting the wattage too high. I'm coming from an unregulated mod, so it's very different. I was looking at the Innokin Coolfire 4 TC100 mod, built in Li-Po pack, and rated for 7.5v and 30A. Can you ACTUALLY vent one from putting the wattage too high? Or does the chipset prevent this? How idiot proof are they really? Thanks!

 

[robot zombie]

Ah... just saw you're looking at a mod with integrated cells. Those are much more idiot proof than any other mod. Can't say I've ever heard of one failing. They're not designed to take more from the batteries than they can give. You're good. Just don't drop it.

The only problem with those internal-battery mods is that once the batteries are down for the count, you have to buy a new mod... ...unless you want to open it up and do some surgery. I would really recommend an 18650 mod for the long term, but if you really wanna keep it simple, then it's not a bad option.

Well... ...I guess I'll leave this here, anyway. It's worth considering if the only reason you want the lipo is for safety. Personally, I trust the chemistry of two 18650's over that of lipo packs. Maybe the lipo mod is playing it safe power-wise, but if something goes wrong in the lipo mod, it'll be worse than if it was an 18650 mod. Lipo's are pretty fragile when it comes to impacts they can take and well... ...you can't rip them out of the mod if they go up. And then you have to trust the built-in charger...

Anyway, here's what I originally wrote (about regulated 18650's...)


You could potentially vent batteries, though it's far less likely.

The mod does plenty to protect you from a catastrophic failure. The chip can detect shorts and also limit current flow coming from the batteries (check the spec marked "input current" - that's the max it can pull from your batteries.) Many also monitor temperatures, which protects you from overheating.

Leading up to the triggering of a failure state, the batteries will typically heat-up gradually as you strain them more and more. Any decent mod will not allow you to gradually run your batteries into venting because of this. It will cut you off long before they reach venting temperatures.

Now, the one thing the mod can't do, is determine the CDR of your batteries, meaning that yes, if you set the wattage too high and your batteries are a really poor match, then yes, rapid failure is a possibility. If you abruptly push a bad battery acutely beyond its limits, then it can vent quite rapidly.

Unlike mech mods, resistance doesn't determine the amount of current drawn from the batteries. It is instead a combination of the wattage set and the voltage of the batteries under load. It will pull the current needed from the batteries to hit x wattage at y voltage. This means that it will pull increasingly more current as the batteries' voltages drop. The max current draw for reggies is low compared to what you can pull approaching .1 on a mech, but it can strain the batteries. Any 30A cell will generally put you just barely in the clear at max wattages, though it's literally right on the line.

So what is the real danger zone, here? Well, in a two-battery mod, 150w is pulling around 20A from fresh batteries and close to 30A by the time it hits the "low battery" cutoff. So 30A cells will be a must. At 100w, we're looking at a much more modest 13A fresh and 20A at end-of-cycle. Ideally, you'd still want 30A cells for 100w and up, but 20A cells can still be used up to 100w if you don't run the batteries all the way down.

The current draw changes depending on the type of mod. The more voltage your get from the batteries, the lower the current needed per watt is.

You can calculate it using the battery drain calculator in Steam Engine. Tick "regulated" and "power regulation". Voltage depends on your battery configuration:

-Dual-series (one cell pointed up and the other pointed down) is 8.4v fresh and ~6v at the cutoff.

-Dual-parallel (both cells pointed the same way) is 4.2v fresh, ~3v dead.

-Triple-parallel (your 200w chips) are 12.6v fresh and ~9v dead.

From there, you just plug in the wattage and the darker blue box on the right will tell you what the amp load on your batteries will be.

Honestly, all of this doesn't matter that much so long as you pick good 20A or 30A cells. Worst case, you will wear them down quicker than average - they may not perform as well. The key at high wattages is to avoid dipping the batteries all the way down to the cutoff. That's where things get kinda rough. Keep the wattage and battery levels sensible for your batteries and you will be fine. Regulated mods are fairly idiot-proof as long as you pick quality, high-drain cells.

 

[H4X0R46]

Ah... just saw you're looking at a mod with integrated cells. Those are much more idiot proof than any other mod. Can't say I've ever heard of one failing. They're not designed to take more from the batteries than they can give. You're good. Just don't drop it.

The only problem with those internal-battery mods is that once the batteries are down for the count, you have to buy a new mod... ...unless you want to open it up and do some surgery. I would really recommend an 18650 mod for the long term, but if you really wanna keep it simple, then it's not a bad option.

Well... ...I guess I'll leave this here, anyway. It's worth considering if the only reason you want the lipo is for safety. Personally, I trust the chemistry of two 18650's over that of lipo packs. Maybe the lipo mod is playing it safe power-wise, but if something goes wrong in the lipo mod, it'll be worse than if it was an 18650 mod. Lipo's are pretty fragile when it comes to impacts they can take and well... ...you can't rip them out of the mod if they go up. And then you have to trust the built-in charger...

Anyway, here's what I originally wrote (about regulated 18650's...)


You could potentially vent batteries, though it's far less likely.

The mod does plenty to protect you from a catastrophic failure. The chip can detect shorts and also limit current flow coming from the batteries (check the spec marked "input current" - that's the max it can pull from your batteries.) Many also monitor temperatures, which protects you from overheating.

Leading up to the triggering of a failure state, the batteries will typically heat-up gradually as you strain them more and more. Any decent mod will not allow you to gradually run your batteries into venting because of this. It will cut you off long before they reach venting temperatures.

Now, the one thing the mod can't do, is determine the CDR of your batteries, meaning that yes, if you set the wattage too high and your batteries are a really poor match, then yes, rapid failure is a possibility. If you abruptly push a bad battery acutely beyond its limits, then it can vent quite rapidly.

Unlike mech mods, resistance doesn't determine the amount of current drawn from the batteries. It is instead a combination of the wattage set and the voltage of the batteries under load. It will pull the current needed from the batteries to hit x wattage at y voltage. This means that it will pull increasingly more current as the batteries' voltages drop. The max current draw for reggies is low compared to what you can pull approaching .1 on a mech, but it can strain the batteries. Any 30A cell will generally put you just barely in the clear at max wattages, though it's literally right on the line.

So what is the real danger zone, here? Well, in a two-battery mod, 150w is pulling around 20A from fresh batteries and close to 30A by the time it hits the "low battery" cutoff. So 30A cells will be a must. At 100w, we're looking at a much more modest 13A fresh and 20A at end-of-cycle. Ideally, you'd still want 30A cells for 100w and up, but 20A cells can still be used up to 100w if you don't run the batteries all the way down.

The current draw changes depending on the type of mod. The more voltage your get from the batteries, the lower the current needed per watt is.

You can calculate it using the battery drain calculator in Steam Engine. Tick "regulated" and "power regulation". Voltage depends on your battery configuration:

-Dual-series (one cell pointed up and the other pointed down) is 8.4v fresh and ~6v at the cutoff.

-Dual-parallel (both cells pointed the same way) is 4.2v fresh, ~3v dead.

-Triple-parallel (your 200w chips) are 12.6v fresh and ~9v dead.

From there, you just plug in the wattage and the darker blue box on the right will tell you what the amp load on your batteries will be.

Honestly, all of this doesn't matter that much so long as you pick good 20A or 30A cells. Worst case, you will wear them down quicker than average - they may not perform as well. The key at high wattages is to avoid dipping the batteries all the way down to the cutoff. That's where things get kinda rough. Keep the wattage and battery levels sensible for your batteries and you will be fine. Regulated mods are fairly idiot-proof as long as you pick quality, high-drain cells.

Cool! Thanks so much for the info! If using a 0.25 ohm coil on this mod at 100w is 20A of current, this would mean the amp draw goes up as the battery dies?

 

[Angrygod50]

Short answer No. The mod will do what it needs to stay within its range and shut down if the battery can't supply enough power for your settings.
Ohms law doesn't directly apply as it does in a mechanical mod. That being said I don't trust internal battery mods as I've had a SMOK M80 vent while charging but that's just me others use them all the time.

 

[H4X0R46]

Short answer No. The mod will do what it needs to stay within its range and shut down if the battery can't supply enough power for your settings.
Ohms law doesn't directly apply as it does in a mechanical mod. That being said I don't trust internal battery mods as I've had a SMOK M80 vent while charging but that's just me others use them all the time.

Alright cool! So say I'm cranking like, 80w from the device, as the battery goes down, it just won't let me fire 80 eventually? And yea, the idea of li-po is kind of unnerving to me, I considered the rx200 but it's more expensive and seems like a higher stepping stone for a noob.

 

[Angrygod50]

It'll say low battery, won't fire or my eLieaf Pico locks and shows lock if you try to fire it. The big advantage to an internal battery is that you don't have to buy batteries or a charger. Lots of love for the Pico around here. If you do go with an external battery mod go here for batteries and a charger.
http://liionwholesale.com/ Samsung 25R or LG HE2 HE4 or HG2 are good choices. JON is member here and well liked.

 

[robot zombie]

Cool! Thanks so much for the info! If using a 0.25 ohm coil on this mod at 100w is 20A of current, this would mean the amp draw goes up as the battery dies?

That is correct. Regulated draws MORE as the batteries deplete. Because it has increasingly less voltage that it can turn into current to feed the coils, it must take more and more current from the batteries themselves. Unregulated takes less, because as voltage drops, so does the amount of current the batteries give at x-resistance.

Alright cool! So say I'm cranking like, 80w from the device, as the battery goes down, it just won't let me fire 80 eventually?

More accurately, it won't let you fire at ANY wattage once the batteries reach a certain voltage threshold. Most won't let you discharge below 3v per battery, which is a safe bit higher than the minimum voltage (aka the over-discharge point) for any battery you would be using.

Though I suppose you'd hit the "low battery" point sooner at higher wattages because the more current is pulled, the more voltage sags. Say a battery is resting at 3.6v. Let's say it dips down to 3.2v @ 50w. The mod will fire. Now, let's take it up to 150w and assume the voltage drops down to 3. The mod will start to fire only to stop a split second later and give a "low battery" message. Maybe you take 10 consecutive hits at 50W and the voltage under load hits 3 - it will also cut out in this case.

Basically, the mod will not allow the batteries to discharge at or below a certain voltage - no matter what. Whenever they hit that voltage, it cuts out.

And yea, the idea of li-po is kind of unnerving to me, I considered the rx200 but it's more expensive and seems like a higher stepping stone for a noob.

Lipos aren't really nototrious or anything, but badly-made ones can and have failed... ...never from user-error. You can do everything right and it can still fail you. When 18650 boxes fail, it's usually user-error, but you never hear about them failing on their own.

Performance-wise, lipos can be very good. I just wouldn't trust a cheap lipo mod to protect the lipo pack from impact (lipo packs are very soft and sometimes the slightest impact/dent/deformation will cause an internal short,) nor would I trust them to implement a totally safe charging circuit.

Safety aside, I think integrated battery mods are an unneeded stepping stone. If you, like most, go on to make a regulated box your main mod, you will eventually have to go 18650.

Good, safe 18650 chargers can be had for $20-$30 bucks. Electrically and physically more rugged and stable batteries can run you as little as $12 a pair. And you can use them with other mods. For a little more than the cost of some lipo mods, you can have a charger, two pairs of batteries, and a top-performing, high-powered mod. Think of it as a necessary investment. It immediately becomes worth it when you upgrade or need new batteries.

The rx200 is a great mod. Many 200w mods are among the best. And they can be pretty inexpensive. I wouldn't say it's harder to use if you're running it in normal wattage mode. It just has more features than a newbie really needs. But that also makes it a good investment, as you can grow into it, rather than having to buy a new mod when you get more comfortable and want more advanced features. Battery life in 3-cell mods is killer, too.

Others may disagree with me there. And you certainly have simpler options, such as the now-classic Sigelei 150w TC, which is about as simple as it gets. There are many that surpass it now, but it's still a solid pick imo. Just drop in the batteries, use the + and - buttons to set wattage, and vape.

 

[H4X0R46]

That is correct. Regulated draws MORE as the batteries deplete. Because it has increasingly less voltage that it can turn into current to feed the coils, it must take more and more current from the batteries themselves. Unregulated takes less, because as voltage drops, so does the amount of current the batteries give at x-resistance.


More accurately, it won't let you fire at ANY wattage once the batteries reach a certain voltage threshold. Most won't let you discharge below 3v per battery, which is a safe bit higher than the minimum voltage (aka the over-discharge point) for any battery you would be using.

Though I suppose you'd hit the "low battery" point sooner at higher wattages because the more current is pulled, the more voltage sags. Say a battery is resting at 3.6v. Let's say it dips down to 3.2v @ 50w. The mod will fire. Now, let's take it up to 150w and assume the voltage drops down to 3. The mod will start to fire only to stop a split second later and give a "low battery" message. Maybe you take 10 consecutive hits at 50W and the voltage under load hits 3 - it will also cut out in this case.

Basically, the mod will not allow the batteries to discharge at or below a certain voltage - no matter what. Whenever they hit that voltage, it cuts out.


Lipos aren't really nototrious or anything, but badly-made ones can and have failed... ...never from user-error. You can do everything right and it can still fail you. When 18650 boxes fail, it's usually user-error, but you never hear about them failing on their own.

Performance-wise, lipos can be very good. I just wouldn't trust a cheap lipo mod to protect the lipo pack from impact (lipo packs are very soft and sometimes the slightest impact/dent/deformation will cause an internal short,) nor would I trust them to implement a totally safe charging circuit.

Safety aside, I think integrated battery mods are an unneeded stepping stone. If you, like most, go on to make a regulated box your main mod, you will eventually have to go 18650.

Good, safe 18650 chargers can be had for $20-$30 bucks. Electrically and physically more rugged and stable batteries can run you as little as $12 a pair. And you can use them with other mods. For a little more than the cost of some lipo mods, you can have a charger, two pairs of batteries, and a top-performing, high-powered mod. Think of it as a necessary investment. It immediately becomes worth it when you upgrade or need new batteries.

The rx200 is a great mod. Many 200w mods are among the best. And they can be pretty inexpensive. I wouldn't say it's harder to use if you're running it in normal wattage mod. It just has more features than a newbie really needs. But that also makes it a good investment, as you can grow into it, rather than having to buy a new mod when you get more comfortable want more advanced features. Battery life in 3-cell mods is killer, too.

Others may disagree with me there. And you certainly have simpler options, such as the now-classic Sigelei 150w TC, which is about as simple as it gets. There are many that surpass it now, but it's still a solid pick imo. Just drop in the batteries, use the + and - buttons to set wattage, and vape.

Thanks so much for the informative post! Really helps a noob understand these things lol So yea, a regulated mod will cut off when the voltage goes too low to protect from battery damage, but when a battery starts to deplete and it's now asking for more amp draw, will the mod actually over draw a batteries amp limit? Or is the board smart enough to cut you off before going over the limit? The mod I considered has a 30A limit, would the board not allow an unsafe draw? Or is there room for user error? Thanks so much again! Much appreciated!

 

[robot zombie]

Thanks so much for the informative post! Really helps a noob understand these things lol So yea, a regulated mod will cut off when the voltage goes too low to protect from battery damage, but when a battery starts to deplete and it's now asking for more amp draw, will the mod actually over draw a batteries amp limit? Or is the board smart enough to cut you off before going over the limit? The mod I considered has a 30A limit, would the board not allow an unsafe draw? Or is there room for user error? Thanks so much again! Much appreciated!

There is still room for user error. It can draw more current than your batteries can take.

If it has a 30A limit, then it will draw 30A if needs it, 30A cells or not. It has no way of knowing what batteries you have. That's why it is important to pick good ones. Ideally, you would want 30A cells for a 30A mod. That way you never have to worry about it taxing the batteries dangerously hard.

All you have to remember is that for two-battery mods, you need 30A cells to go much over 100w. For anything under 100w, 20A is perfectly fine. That is really all there is to using a regulated mod safely. VTC4's will be safe at any wattage. Samsung 25r's are great if you're not maxing the wattage all of the time. They can actually take a good bit of abuse.

With the rx200 or any other triple-battery mod, you can go even higher thanks to the higher battery voltage. You could take Samsung 25r's all the way up to 150w and only be pulling 18A before the low battery cutoff.

And again, none of this applies to mods with built-in batteries. The chip is configured to never over-discharge the batteries. If it has a 30A limit, then that's what the batteries can give and that's the most the chip will ever take.

 

[The Cromwell]

One thing though if you use substandard batteries in a regulated mod it is possible they could vent.
But as long as you use LG, Samsung, or Sony or other good brands of at least 20 amp CDR batteries you should be ok.
One tip you will not find any 3000 mah 18650 batteries with a true over 20 amp CDR rating.
And I do not think there are any under 3000 mah 18650's with over a 35 amp true CDR rating either.

 

[H4X0R46]

There is still room for user error. It can draw more current than your batteries can take.

If it has a 30A limit, then it will draw 30A if needs it, 30A cells or not. It has no way of knowing what batteries you have. That's why it is important to pick good ones. Ideally, you would want 30A cells for a 30A mod. That way you never have to worry about it taxing the batteries dangerously hard.

All you have to remember is that for two-battery mods, you need 30A cells to go much over 100w. For anything under 100w, 20A is perfectly fine. That is really all there is to using a regulated mod safely. VTC4's will be safe at any wattage. Samsung 25r's are great if you're not maxing the wattage all of the time. They can actually take a good bit of abuse.

With the rx200 or any other triple-battery mod, you can go even higher thanks to the higher battery voltage. You could take Samsung 25r's all the way up to 150w and only be pulling 18A before the low battery cutoff.

And again, none of this applies to mods with built-in batteries. The chip is configured to never over-discharge the batteries. If it has a 30A limit, then that's what the batteries can give and that's the most the chip will ever take.

Alright, so for the internal battery mod that's a 30A lipo pack, the board shouldn't allow more than 30A correct? Safer bet might be to step it up and just get the RX200 I'm thinking though........ Just to also clarify, finding the amp draw of each cell in an RX200 would be, example: 100w(wattage used)x3(number of batteries in use)x 3(lowest safe voltage with .2 taken for inefficiencies) would equal the amp draw per battery correct? Bear with me, I'm still learning

EDIT!: I meant divided by, the multiplying was a typo! LOL

Another EDIT: How close should you go to the amp limit of a battery? I heard somewhere say to draw the line at 80% of what it's capable of, but not sure if this is correct. Thanks again!

 

[The Cromwell]

If a battery has been tested by Mooch as a true 30 amp CDR battery then it can safely provide 30 amps continuously.
It will get warm though and running a battery at or near max CDR most of the time will shorten it's lifespan.
Also a 2000 mah 30 amp cell may only produce 1200 mah at max drain.
So ti will run down quicker.

With that said a true 30 amp battery can be ran at maybe 40 amps or so for short bursts.

 

[robot zombie]

Alright, so for the internal battery mod that's a 30A lipo pack, the board shouldn't allow more than 30A correct? Safer bet might be to step it up and just get the RX200 I'm thinking though........ Just to also clarify, finding the amp draw of each cell in an RX200 would be, example: 100w(wattage used)x3(number of batteries in use)x 3(lowest safe voltage with .2 taken for inefficiencies) would equal the amp draw per battery correct? Bear with me, I'm still learning

EDIT!: I meant divided by, the multiplying was a typo! LOL

Alright, now you've got me confused. But yes, the lipo mod will never exceed 30A from its 30A battery pack. But as for the rest, check it out:

RX200 runs 3 batteries in series. The voltage for each battery is additive in series, (while current draw remains the same per battery as it would for just one,) so if each battery is 4.2v fresh and 3v at the end, then the RX200 has an output voltage range of 9v-12.6v.

We then take whatever wattage we're designating and divide it by the voltage to figure out the current draw on each cell. So 100w with fresh batteries would be 100w / 12.6v = 7.9A. For basically "dead" batteries we have 100w / 9v = 11.1A. All three cells will bear these same current loads. Nice and simple calculation.

Now, no mod is 100% efficient, steam engine assumes 90% efficiency for the converter. It may be 88% at lower resistances and 95% at higher resistances (this has to do with how much voltage has to be stepped down - the more it gets pushed down, the more power is lost as heat) 90% is a good, conservative approximation. The current you calculate-out at 90% efficiency will be a touch higher than what you see in reality.

Anyway, this means it has to generate some extra watts to hit the target. So you calculate 10% of 100w, which is of course 110w, and then you divide that by the voltage as above for a reasonable approximation.

But you don't really have to go through any of this trouble - this is just so you understand the concept.

Just use steam engine's battery drain calculator. I included a rundown on how to use it in my first post. All you have to do is plug in the numbers and it will give you all of the info you need - it even factors for efficiency and can tell you how much current/voltage hits your coil, if you plug-in the resistance.

Always remember to prioritize the low-battery-voltage current, as that's the peak current load. It can go maybe 5A-10A past the CDR of your batteries without doing too much harm, as they will only approach that towards the end. But try not to push it too hard. 25r's and VTC4's won't vent under this sort of strain, but they will get run into the ground after a while of doing this.

Another EDIT: How close should you go to the amp limit of a battery? I heard somewhere say to draw the line at 80% of what it's capable of, but not sure if this is correct. Thanks again!

It's generally considered a wise practice, sure. Not entirely necessary with regulated mods. You may want to leave the 20% of headroom for fresh batteries, just so that they don't get pushed too hard as the voltage goes down and you start getting closer to 100% of the CDR.

I'd also like to second the recommendation of Mooch's tests. They are very revealing. Just google "mooch battery" or something and you'll find both an index of detailed appraisals for virtually all of the common batteries (and even rarer ones!) as well as regularly updated charts showing all of his tested CDR's vs reported CDR's and how far past those you can or can't go.

Some batteries actually do just fine past their CDR, while others aren't even suitable BELOW their CDR. Guy really knows his stuff and has contributed a lot to vaping with his work. Take advantage of it.

That, or nab a bunch of genuine VTC4's and worry about none of this, ever.

 

[H4X0R46]

Alright, now you've got me confused. But yes, the lipo mod will never exceed 30A from it's 30A battery pack. But as for the rest, check it out:

RX200 runs 3 batteries in series. The voltage for each battery is additive in series, (while current draw remains the same per battery as it would for just one,) so if each battery is 4.2v fresh and 3v at the end, then the RX200 has an output voltage range of 9v-12.6v.

We then take whatever wattage we're designating and divide it by the voltage to figure out the current draw on each cell. So 100w with fresh batteries would be 100w / 12.6v = 7.9A. For basically "dead" batteries we have 100w / 9v = 11.1A. All three cells will bear these same current loads. Nice and simple calculation.

Now, no mod is 100% efficient, steam engine assumes 90% efficiency for the converter. It may be 88% at lower resistances and 95% at higher resistances (this has to do with how much voltage has to be stepped down - the more it gets pushed down, the more power is lost as heat) 90% is a good, conservative approximation. The current you calculate-out at 90% efficiency will be a touch higher than what you see in reality.

Anyway, this means it has to generate some extra watts to hit the target. So you calculate 10% of 100w, which is of course 110w, and then you divide that by the voltage as above for a reasonable approximation.

But you don't really have to go through any of this trouble - this is just so you understand the concept.

Just use steam engine's battery drain calculator. I included a rundown on how to use it in my first post. All you have to do is plug in the numbers and it will give you all of the info you need - it even factors for efficiency and can tell you how much current/voltage hits your coil, if you plug-in the resistance.

Always remember to prioritize the low-battery-voltage current, as that's the peak current load. It can go maybe 5A-10A past the CDR of your batteries without doing too much harm, as they will only approach that towards the end. But try not to push it too hard. 25r's and VTC4's won't vent under this sort of strain, but they will get run into the ground after a while of doing this.


It's generally considered a wise practice, sure. Not entirely necessary with regulated mods. You may want to leave the 20% of headroom for fresh batteries, just so that they don't get pushed too hard as the voltage goes down and you start getting closer to 100% of the CDR.

I'd also like to second the recommendation of Mooch's tests. They are very revealing. Just google "mooch battery" or something and you'll find both an index of detailed appraisals for virtually all of the common batteries (and even rarer ones!) as well as regularly updated charts showing all of his tested CDR's vs reported CDR's and how far past those you can or can't go.

Some batteries actually do just fine past their CDR, while others aren't even suitable BELOW their CDR. Guy really knows his stuff and has contributed a lot to vaping with his work. Take advantage of it.

That, or nab a bunch of genuine VTC4's and worry about none of this, ever.

Thanks! Sorry for the confusion, I was calculating amp draw correctly in this case, just said it in a super confusing way haha but thanks for the info! Resistance play a part in regulated mods? I heard something about resistance and it determining the voltage needed, is this a concern? And for that matter, how high can you really go for voltage? I would assume 9v to be safe just because it's the devices lowest voltage, but unsure if I'm right. Thank you so much! I'll probably get me an RX200 when I get the cash, and some good 18650s!

 

[robot zombie]

Thanks! Sorry for the confusion, I was calculating amp draw correctly in this case, just said it in a super confusing way haha but thanks for the info! Resistance play a part in regulated mods? I heard something about resistance and it determining the voltage needed, is this a concern? And for that matter, how high can you really go for voltage? I would assume 9v to be safe just because it's the devices lowest voltage, but unsure if I'm right. Thank you so much! I'll probably get me an RX200 when I get the cash, and some good 18650s!

No problem. I geek hard on this stuff. Always willing to try and teach people who want to learn.

No danger in running up the max voltage. It's merely a performance factor. Resistance and output voltage don't affect how the mod gets the power, only how it gives the power. The mod literally cannot physically output voltage that presents any sort of electrical hazard, by design. At worst, it may fry a coil that can't take the heat.

You basically never have to worry about the voltage that the mod chooses. You don't set the voltage directly. All you have to do is set the wattage you want and it will take care of supplying the proper voltage and current to the coil.

The mod will ALWAYS pull the same current from the same batteries kicking the same voltage up to the same wattage. Doesn't matter if it's a 0.1 or a 1 on top. The chip will then take the power generated by the batteries and exchange voltage for current as per ohms law. A coil at w resistance will always need x volts and y amps to hit z wattage.

So for example, lets consider two scenarios. We have two identical RX200s set to 150w with batteries kicking out 12v. One is powering a .1, while the other is powering a .5.

Both mods will pull 14A @ 12v. This is the input current/voltage, or what your batteries provide to the circuit.

The .1 build will be fed a whopping ~39A @ a measly 3.9v. The .5 OTOH, will be fed ~17A @ a more substantial 7.8v. These figures are the output current/voltages, which are what the circuitry then generates.

So what happened here? It's the magic of buck converters. Since the mod is able to take voltage and turn it into current, it can safely drive coils of very low resistances to very high wattages. It allows you to feed 39A to your atty for only 14A from your batteries. Since a lower resistance coil needs less voltage but more current to hit the same wattage, the mod simply exchanges one for another after the fact.

This does create a threshold where certain coils cannot be powered to certain wattages. According to ohm's law, a 1-ohm build would require 12v to be pushed to 150w. You cannot substitute current for voltage with a step-down mod - you need a voltage push it simply doesn't have to get the right amount of current through the coil.

A mod's output voltage is always at least a little lower than the batteries' output voltage. The RX200 has a max output voltage of 9v, so it cannot power a 1-ohm build all the way up to 100w, even with batteries kicking at 12v. It may show 100w on the display, but the most it will actually be feeding is 80w.

Remember, the battery strain is determined purely by the wattage and the voltage of the batteries, not what goes to the coil, so what gets outputted isn't a safety concern. And actually, the closer you get to the batteries' native voltage, the less strain you put on the converter, meaning battery life is better, watt for watt. Higher output voltage wastes less power.

It just means that you have to choose your resistance according to how much power you want. Higher resistance coils need more voltage to reach the same power levels as lower resistance ones, meaning the higher the resistance, the lower the max wattage is. There are sweet spots that allow you the full range of power that the mod has to give. You want to shoot for the minimum amount of voltage step-down needed to hit the desired wattage. That gives the best performance, power-wise.

Another oddity is that some mods have a max output voltage that is above the minimum input voltage. Many 150w mods are this way. They may have a max output of 7.5v, but with a min battery voltage of 6. This means that if a coil needs 7.5v, but the batteries don't have it to give, you will undershoot the wattage. It's not dangerous. Just a limitation of the device. The reason the RX200 caps the voltage output at the 9v input cutoff is to avoid this silliness. It's just one way that a mod can show a higher wattage than it's actually packing.

 

[H4X0R46]

No problem. I geek hard on this stuff. Always willing to try and teach people who want to learn.

No danger in running up the max voltage. It's merely a performance factor. Resistance and output voltage don't affect how the mod gets the power, only how it gives the power. The mod literally cannot physically output voltage that presents any sort of electrical hazard, by design. At worst, it may fry a coil that can't take the heat.

You basically never have to worry about the voltage that the mod chooses. You don't set the voltage directly. All you have to do is set the wattage you want and it will take care of supplying the proper voltage and current to the coil.

The mod will ALWAYS pull the same current from the same batteries kicking the same voltage up to the same wattage. Doesn't matter if it's a 0.1 or a 1 on top. The chip will then take the power generated by the batteries and exchange voltage for current as per ohms law. A coil at w resistance will always need x volts and y amps to hit z wattage.

So for example, lets consider two scenarios. We have two identical RX200s set to 150w with batteries kicking out 12v. One is powering a .1, while the other is powering a .5.

Both mods will pull 14A @ 12v. This is the input current/voltage, or what your batteries provide to the circuit.

The .1 build will be fed a whopping ~39A @ a measly 3.9v. The .5 OTOH, will be fed ~17A @ a more substantial 7.8v. These figures are the output current/voltages, which are what the circuitry then generates.

So what happened here? It's the magic of buck converters. Since the mod is able to take voltage and turn it into current, it can safely drive coils of very low resistances to very high wattages. It allows you to feed 39A to your atty for only 14A from your batteries. Since a lower resistance coil needs less voltage but more current to hit the same wattage, the mod simply exchanges one for another after the fact.

This does create a threshold where certain coils cannot be powered to certain wattages. According to ohm's law, a 1-ohm build would require 12v to be pushed to 150w. You cannot substitute current for voltage with a step-down mod - you need a voltage push it simply doesn't have to get the right amount of current through the coil.

A mod's output voltage is always at least a little lower than the batteries' output voltage. The RX200 has a max output voltage of 9v, so it cannot power a 1-ohm build all the way up to 100w, even with batteries kicking at 12v. It may show 100w on the display, but the most it will actually be feeding is 80w.

Remember, the battery strain is determined purely by the wattage and the voltage of the batteries, not what goes to the coil, so what gets outputted isn't a safety concern. And actually, the closer you get to the batteries' native voltage, the less strain you put on the converter, meaning battery life is better, watt for watt. Higher output voltage wastes less power.

It just means that you have to choose your resistance according to how much power you want. Higher resistance coils need more voltage to reach the same power levels as lower resistance ones, meaning the higher the resistance, the lower the max wattage is. There are sweet spots that allow you the full range of power that the mod has to give. You want to shoot for the minimum amount of voltage step-down needed to hit the desired wattage. That gives the best performance, power-wise.

Another oddity is that some mods have a max output voltage that is above the minimum input voltage. Many 150w mods are this way. They may have a max output of 7.5v, but with a min battery voltage of 6. This means that if a coil needs 7.5v, but the batteries don't have it to give, you will undershoot the wattage. It's not dangerous. Just a limitation of the device. The reason the RX200 caps the voltage output at the 9v input cutoff is to avoid this silliness. It's just one way that a mod can show a higher wattage than it's actually packing.

Alright so it pulls the same amount of voltage no matter what resistance your coil? How do you calculate the amp draw without keeping resistance in mind? The equation is: wattage/number of batteries/minimum voltage. Where in the equation do you account for the coil resistance? That part has me stumped. A lower ohm coil needs more amps to run, and the calculation to find amp draw per battery omits the factor of resistance completely. I would hate to put the wattage too high and vent my cells lol

Does the circuit board pull the same amount of amps regardless on the coil resistance?

EDIT: found this little snippet on a reddit thread. "Atomizer resistance has nothing to do with the current being drawn from your battery on a regulated mod." So this means, you could use ANY resistance of coil that the mod will fire, and it doesn't ever affect how much amps it's pulling?

 

[robot zombie]

Does the circuit board pull the same amount of amps regardless on the coil resistance?

EDIT: found this little snippet on a reddit thread. "Atomizer resistance has nothing to do with the current being drawn from your battery on a regulated mod." So this means, you could use ANY resistance of coil that the mod will fire, and it doesn't ever affect how much amps it's pulling?

Yes. I know it sounds counterintuitive, but that's how it works. The mod initially generates the wattage in a separate part of the circuit that the coil is not a part of. The coil doesn't need all of the voltage that the batteries are pushing. And when the voltage is decreased, the power doesn't just vanish - that's physically impossible - the batteries can't be made to kick out less voltage than they naturally give, so the mod has to do something with it. It simply changes form. Watts are watts.

The current and voltage going to the coil are different from the current and voltage going to the batteries. That's why you'll see mods that can run coils as low as .05. The reason they don't explode is because they don't have to pull all of that current from the batteries.

The current draw is determined by the battery voltage. 3 freshly charged batteries wired in series kick out 12v. When dead, they're down to 9. You divide the wattage you set by those numbers to get the amps drawn from the batteries when either fresh or depleted, respectively.

 

[H4X0R46]

Yes. I know it sounds counterintuitive, but that's how it works. The mod initially generates the wattage in a separate part of the circuit that the coil is not a part of. The coil doesn't need all of the voltage that the batteries are pushing. And when the voltage is decreased, the power doesn't just vanish - that's physically impossible. It simply changes form. Watts are watts.

The current and voltage going to the coil are different from the current and voltage going to the batteries. That's why you'll see mods that can run coils as low as .05. The reason they don't explode is because they don't have to pull all of that current from the batteries.

The current draw is determined by the battery voltage. 3 freshly charged batteries wired in series kick out 12v. When dead, they're down to 9. You divide the wattage you set by those numbers to get the amps drawn from the batteries.

Thanks man! I appreciate the lesson! I went on a few forums and a lot of users didn't wanna help a noob haha I'm probably gonna get me an rx200, a set of Samsung 25R batteries, and a nitecore D4 charger! Now where to get this stuff and not spend $100 is my next venture.... but thanks again!

 

[skt239]

The title reads like you are looking for a regulated mod that can be vented easily

 

[H4X0R46]

The title reads like you are looking for a regulated mod that can be vented easily

Ya know what? I looked at my thread later and laughed because you're right! At a glance, I read "how to easily vent a mod." And I thought "damn, I sound like a tool" hahahaha