Eleaf iStick ... compact 20w box mod

[wizzard]

This is starting to get confusing. What I have found is If you were vaping at 8.5 watts on whatever device just drop down to 7.5 on the istick. Still not understanding the whole issue with this. I have noticed it does get hotter than my MVP. MVP at 8.5 watts and istick at 7.5 watts. That fixed it for me.
But I am now confused on all the talk above. What is wrong with just reducing your watts if it is getting hotter than you want?

 

[Tripster]

I am not an engineer so I will still enjoy my vape when I get mine.

 

[wizzard]

I am not an engineer so I will still enjoy my vape when I get mine.

Agreed

 

[Tripster]

I get mine tomorrow, yay!

 

[Sparks]

Hey Sparks.

With very few exceptions, PWM (pulse-width-modulation) boosts the battery voltage to a set level, usually the device's highest voltage, sometimes a bit higher. Then it pulses that voltage several times per second to obtain the overall voltage that's been set. In the case of the iStick, it apparently boosts voltage to 5.8V. Then it pulses 5.8V 48 times per second (48 Hz). Those 48 pulses per second can be very short or much longer until the output voltage looks constant on test equipment. The percentage of time (per second) that the voltage is on (vs. off) is called it's duty cycle.

The below image shows a device with a peak of 5V firing at 20%, 50% & 75% duty cycles.

View attachment 6865

Here's where it gets kind of tricky... If we multiply the peak voltage (Vpk) by the duty cycle (C%) we get the average voltage (Vavg, shown above). We know that firing a Vavg of 3.5V into our 1.8Ω coil creates much higher Wattage at the coil than a constant 3.5V.

For example, using the iStick's specs:

Ohm's Law (V²/R=W) tells us that a constant 3.5V into a 1.8Ω coil will give us 6.8W.

W also know a different formula is used to determine Watts from a PWM Vavg signal:
(Vpk²/R) * C% = W or in our case, (5.8²/1.8Ω) * (3.5/5.8) = 11.3W

6.8W vs. 11.3W is a big difference.
We use RMS (root-mean-square) Voltage to obtain the Watts that constant Voltage provides.

It is suspected that the iStick is plugging an Average Voltage (Vavg) into Ohm's Law, rather than an RMS or constant voltage, providing much higher Watts at the coil. If true, it's all about faulty software NOT hardware and could be fixed rather simply and cheaply for future runs. Few people are questioning whether the iStick is firing below native battery Voltage. We know they're using PWM. We're questioning the formula used to set and display the voltage; ie average voltage (Vavg) or RMS voltage (Vrms).

Hope this helps!

Yes..you explanation HELPS A LOT!!!!
Thank you very much, you to are also a very very good explain-er, I have a fundamental knowledge but certainly not at your level or Hermits but I am always grateful to you obviously trained pro's who will take the time to break this down into meaningful statistics and operational fundamentals.
I believe I'll be able to use your explanation to make my case.
This has been IMHO falsely advertised as the basic operations of this device just don't hold up to their statements regarding the variable volts, I can turn this device to 3.0v on a fully charged battery and it makes absolutely no difference, I can then take the same Aspire and run it on the MVP, SVD, Suitcase, Clouper, Vamo and well the difference is clear, and your statistics only clarify what is actually going on with this software, but the taste buds don't lie and the difference is huge. Been talking to some UK vape friends and the talk is heating up there also,
A friend there said he thought the reason there isn't a huge uproar like when the DNA20 chip situation happened which I mentioned earlier which was exactly the same situation as this, is that most people and with the advancement in coil technology and being able to handle higher voltages is what not causing an uproar, did that make sense, a lot of people vape hotter coils and maybe Ismoka guessed that would be what keeps this from being an issue?? I don't vape hot coils or usually above 1.8ohm, now if I wanted to fire up a quad build and some straight VG juice this device would be perfect.
But this device certainly doesn't come close to the capabilities of the MVP, just a cool looking device that does work and only the individual can determine if this device is the one for their vape style, and that means buying one just to find out since the advertising isn't accurate.
Had they simply chosen the correct software as you mentioned this would definitely have been the Innokin MVP killer and quit easily, they basically caught Innokin asleep at the wheel, remains to be seen how Innokin responds to this release of the Istick might be very cool indeed and I doubt they Innokin would make this same mistake.
Thank you again for the great explanation, it is valuable to me, I'm not laying down on this and I've got way to much time on my hands being I'm retired and been vaping for quit awhile and really hate it when I get lead along and buy equipment that doesn't deliver as advertised.
Thanks

 

[aldenf]

When my iStick arrives in the mail, I will enjoy it immensely. Assuming there is a problem with the iStick's engineering, it's usefulness will be greatly reduced, especially for low-wattage vapers (ie. newbies and "plug & players"). It is not a good replacement for EGO-type batteries. The sad part? If Eleaf had done this right, it would force all the other manufacturers to get their acts together and make solid devices at reasonable/appropriate prices.

Just my opinion. I could be wrong.

 

[Sparks]

This is starting to get confusing. What I have found is If you were vaping at 8.5 watts on whatever device just drop down to 7.5 on the istick. Still not understanding the whole issue with this. I have noticed it does get hotter than my MVP. MVP at 8.5 watts and istick at 7.5 watts. That fixed it for me.
But I am now confused on all the talk above. What is wrong with just reducing your watts if it is getting hotter than you want?

That's the issue, on a fully charged battery 4.2v you can NOT down regulate, you can turn this down to 3.0v and it's still vaping at 4.2v, UNTIL you get to about half bar on your battery meter than you are probably at about 3.6v remaining power in your battery so then you can up regulate to 3.8v

 

[Sparks]

When my iStick arrives in the mail, I will enjoy it immensely. Assuming there is a problem with the iStick's engineering, it's usefulness will be greatly reduced, especially for low-wattage vapers (ie. newbies and "plug & players"). It is not a good replacement for EGO-type batteries. The sad part? If Eleaf had done this right, it would force all the other manufacturers to get their acts together and make solid devices at reasonable/appropriate prices.

Just my opinion. I could be wrong.

Your dead on pal, my ego twist is more vapable than this Istick, for MY applications Aspire with a 1.5 ohm coil, so it's really sad and frankly makes me mad because I was looking for something that would replace the MVP I've been using as my out and about vape, but to not be able to regulate it??
It's back to the MVP and the taste difference is huge, mainly I'm not frying the hell out of my coil, and you can't even turn it to 3.0v and expect any difference, so all you can do is charge it half way then you can get a 3.8v setting and even then it's off taste compared to a MVP or any other device I've tried them all and compared them all to this Istick, a real bummer but again for the people who are feeling a buzz kill, look it's all in how YOU vape, but frankly this conversation should not be even happening.

 

[Tripster]

Never mind, I am gettin my iStick today...SWEET!

 

[kelli]

i guess i need to stop reading this thread. it's all unnecessary worry IMO. i have been using my i-sticks non stop since saturday morning and have had no issues whatsoever. no burnt coils, no burnt juice, no explosions. just great taste and lots of vapor. and i don't even know what i'm doing when it comes to ohms, watts and volts!!!

 

[Tripster]

i guess i need to stop reading this thread. it's all unnecessary worry IMO. i have been using my i-sticks non stop since saturday morning and have had no issues whatsoever. no burnt coils, no burnt juice, no explosions. just great taste and lots of vapor. and i don't even know what i'm doing when it comes to ohms, watts and volts!!!

 

[Sparks]

Just got a note from Phil B. and he is going to test the Istick on his equipment, this should be good,

Thanks Phil, the uproar is starting, I'm in contact with Ismoka regarding how this was marketed as a variable volt, there's some fellas over at the underground forum who have scoped this and confirmed problems, but your skill and reputation will really bring this to the forefront.
Thanks for the reply I know your busy guy, keep up the great work it's greatly appreciated.
****
Tacoma WA

On 10/6/2014 7:39 AM, Phil Busardo wrote:

Going to get to it right after the Sigelei 100 which I'm using now. So soon!!

-Phil Busardo

 

[TheWestPole]

I'm loving this controversy! It's bringing out everybody's best critical thinking.

 

[Sparks]

LMAOF, beautifully said, maybe hyper critical???

 

[kelli]

phil busardo will deliver us from evil!!!

 

[Midniteoyl]

That's the issue, on a fully charged battery 4.2v you can NOT down regulate, you can turn this down to 3.0v and it's still vaping at 4.2v, UNTIL you get to about half bar on your battery meter than you are probably at about 3.6v remaining power in your battery so then you can up regulate to 3.8v

Not from my experience on the one I have.. 3v is still 3v avg.. It can and does modulate the PW to get there. Same as a VAMO or VTR as far as I can tell. The VAMO in stacked mode is 'hotter' a vape than the MVP 'cause it peaks the voltage higher, but it still modulates it down.

 

[Midniteoyl]

BTW, this on what it reads as 1.9 - 2.0 ohm. Maybe it has a 'sweet spot' like the MVP where it actually does regulate accurately, but has a good amount of error higher or lower..? Dunno.

I do know the wifes been using it for a couple to 3 days now on a Nautilus BVC and it hasnt gone burnt tasting like her VAMO did..

 

[Lefty]

Then of course there's this one where he thinks it's a little underpowered. That is delivering slightly less than indicated. The whole release is like an off Broadway production of Goldilocks.

 

[wizzard]

Mine is working perfect. I would never replace my MVP it is still my favorite but the istick is just an extra mod along with my to many others that I have collected. I just set mine on watts and find the perfect vape with the istick. I don't have to get so technical like some of you all do. Just set it and enjoy the vape.

 

[Sparks]

phil busardo will deliver us from evil!!!

Amen..

 

[Lefty]

Mine is working perfect. I would never replace my MVP it is still my favorite but the istick is just an extra mod along with my to many others that I have collected. I just set mine on watts and find the perfect vape with the istick. I don't have to get so technical like some of you all do. Just set it and enjoy the vape.

That's great. It was those that weren't able to find the perfect vape that I suspect led to those technical questionings. To see why that might be so.

 

[bystander]

I've had mine for a few days now, and I don't see what all the ruckus is about. Just adjust your volts to get to your desired wattage and off you go - no burning juice/s whatsoever. Am I missing something? Or are we making molehills out of mountains?

BTW, I wholeheartedly *love* this little thing - definitely stealthy while packing a mean punch! To the point that I'm switching from Nauti's back to Vivi Nova's to work around the overhang.

 

[BigDaddyQ]

Received on Saturday. Vaped like a champ. Dropped then accidentally stepped on it this morning...... broken down switch. Sometimes life sucks. I think I will wait until the dust settles before buying another one. But while I had it it worked like a champ. RIP little black iStick.

 

[Randy Lahey]

Is this good for beginner vape users?

 

[BigDaddyQ]

Is this good for beginner vape users?

I consider this a step up from variable voltage ego/evod pen vapes. Quite possibly their successor given the price.

 

[Tripster]

The Beyond Vape Silo Lite Tank fits flawlessly and adds a great balanced weight to the iStick!

 

[Sparks]

Hey Sparks.

With very few exceptions, PWM (pulse-width-modulation) boosts the battery voltage to a set level, usually the device's highest voltage, sometimes a bit higher. Then it pulses that voltage several times per second to obtain the overall voltage that's been set. In the case of the iStick, it apparently boosts voltage to 5.8V. Then it pulses 5.8V 48 times per second (48 Hz). Those 48 pulses per second can be very short or much longer until the output voltage looks constant on test equipment. The percentage of time (per second) that the voltage is on (vs. off) is called it's duty cycle.

The below image shows a device with a peak of 5V firing at 20%, 50% & 75% duty cycles.

View attachment 6865

Here's where it gets kind of tricky... If we multiply the peak voltage (Vpk) by the duty cycle (C%) we get the average voltage (Vavg, shown above). We know that firing a Vavg of 3.5V into our 1.8Ω coil creates much higher Wattage at the coil than a constant 3.5V.

For example, using the iStick's specs:

Ohm's Law (V²/R=W) tells us that a constant 3.5V into a 1.8Ω coil will give us 6.8W.

W also know a different formula is used to determine Watts from a PWM Vavg signal:
(Vpk²/R) * C% = W or in our case, (5.8²/1.8Ω) * (3.5/5.8) = 11.3W

6.8W vs. 11.3W is a big difference.
We use RMS (root-mean-square) Voltage to obtain the Watts that constant Voltage provides.

It is suspected that the iStick is plugging an Average Voltage (Vavg) into Ohm's Law, rather than an RMS or constant voltage, providing much higher Watts at the coil. If true, it's all about faulty software NOT hardware and could be fixed rather simply and cheaply for future runs. Few people are questioning whether the iStick is firing below native battery Voltage. We know they're using PWM. We're questioning the formula used to set and display the voltage; ie average voltage (Vavg) or RMS voltage (Vrms).

Hope this helps!

Your explanation is becoming very valuable and I understand what your explaining here, I also need to let you know that I am plagiarizing the hell out of your work, I hope you don't mind and I don't believe you would, the engineers at Ismoka are frankly baffled I'm starting to believe, I'm thinking they didn't figure anyone would notice...
If your not precisely dead on with your stats then damn close and any discrepancies would be very minor, I for one am impressed and I'm thinking others are as well and are taking serious second looks, I posted awhile ago, here, that Phil Busardo emailed me and he is also going to scope this soon, he has mass equipment also, have one other techy looking into this also and came back to review your post to make sure I had some stats correct, greatly appreciated.
I personally mess with a lot of modding so this is not mystery but difficult to fully grasp being I don't mess with the operations of a chip set to this degree, what is see is what I get as long as it performs.
I can almost assure you one thing, the V2 Istick will be the MVP killer unless Innokin, who I'm sure has just gotten that proverbial shot across their bow, comes up with something and very quickly to compete with this Istick, Ismoka caught Innokin MVP with their pants down that's a fact and Innokin is probably scrambling. Thanks again and if you see your material floating around well sorry and I hope you don't mind, maybe next time you won't do such good work..

 

[Tripster]

Fresh first impressions of my very first ever Regulated VV/VW Device...this tiny shit is awesome and hits like an asteroid the size of the Sun!

 

[Sparks]

Received on Saturday. Vaped like a champ. Dropped then accidentally stepped on it this morning...... broken down switch. Sometimes life sucks. I think I will wait until the dust settles before buying another one. But while I had it it worked like a champ. RIP little black iStick.

You know you might be able to get a torx bit and remove the top cap and the bottom cap, and you'll see some plastic slips that hold the buttons in, you might be able to fix it, and yes I've taken mine apart already, you pull those plastic slip things out and turn it over and the buttons just fall out, now getting them back in is much harder, but what do you have to lose?

 

[Sparks]

That's great. It was those that weren't able to find the perfect vape that I suspect led to those technical questionings. To see why that might be so.

No not really, I'm the one to first raise the issue and I've vaped and modded for a very long time and technical questions are what makes devices like this available and better in the end run.

 

[Tripster]

I have been strictly using unregulated mech mods since 2010 and I have never thought I would say this but...um, holy shit...regulated devices pack a seriously mean punch and the delivery of nicotine is intense. I had to lay down cause of the nicotine rush! I will retire my Simplicity as a backup and the iStick is now my EDVD (Every Day Vaping Device).

Impressive!

 

[Lefty]

No not really, I'm the one to first raise the issue and I've vaped and modded for a very long time and technical questions are what makes devices like this available and better in the end run.

You may have misconstrued my point. That's great was in response to his satisfaction with it. The rest was a justification for the technical questions raised by those whose results didn't match his. There is a monstrous sized thread on this at ecf (nearly 2500 posts ATM) so the issue has been raised a few times.
I don't have one as yet so I can't contribute MY experience. I do find it interesting that some folks are so invested in liking it that they discount other peoples that don't match. I guess it's not possible that an inexpensive, brand new china mod could vary from unit to unit. As to some questions about why so technical I think the whole "Why are there geeks?" thing would definitely need a whole new thread.
Edit: sorry about the edit but somehow the quoted part was hosed.

 

[Tripster]

Before the possible release of V2...most likely between 6-12 months from now...I am goin to invest in 2 more of these.

 

[Whiskey]

I just grabbed another on an e-mail alert

 

[Tripster]

I just grabbed another on an e-mail alert

I am seriously impressed with this Device that I am actually speechless.

 

[Whiskey]

I know right??

 

[moecat]

I just grabbed another on an e-mail alert

Greedy!!!

 

[Whiskey]

You get one yet Moe?? I thought I heard you did...
I am giving a couple family members one for Christmas, they hate complicated so this will be perfect for them

 

[moecat]

You get one yet Moe?? I thought I heard you did...
I am giving a couple family members one for Christmas, they hate complicated so this will be perfect for them

....... some moderator you are

See post #285

 

[Tripster]

I actually enjoy seeing how long I take a hit for, that is neat-o!

 

[Whiskey]

....... some moderator you are

See post #285

Who loves you huh???

 

[Randy Lahey]

whats the better value? 10% discount on istick on ebay or a free e liquid from the store? http://www.eleafus.com/e-cigarette/eleaf-istick.html

 

[Tripster]

whats the better value? 10% discount on istick on ebay or a free e liquid from the store? http://www.eleafus.com/e-cigarette/eleaf-istick.html

http://indyvaporshop.com/20welisfukit.html + VTFORUM code

 

[Randy Lahey]

http://indyvaporshop.com/20welisfukit.html + VTFORUM code

isn't an eliquid a better value?

 

[Tripster]

isn't an eliquid a better value?

That is for the Full Kit and that bottle truly isn't free.

 

[Hermit]

Few people are questioning whether the iStick is firing below native battery Voltage. We know they're using PWM. We're questioning the formula used to set and display the voltage; ie average voltage (Vavg) or RMS voltage (Vrms).!

Excellent explanation there, @aldenf!

It's maddening how long it's taking mine to travel to me, and I'm holding off from absolute statements until I test it, but... if it's boosting to 5.8V and reducing with PWM calculated at Vavg instead of Vrms, then the lowest Vrms voltage it would be able to output is 4.17V - close enough to a fully charged battery to give the impression that its lower limit is set by battery voltage.

 

[kelli]

Received on Saturday. Vaped like a champ. Dropped then accidentally stepped on it this morning...... broken down switch. Sometimes life sucks. I think I will wait until the dust settles before buying another one. But while I had it it worked like a champ. RIP little black iStick.

sounds just like something i'd do

 

[aldenf]

Excellent explanation there, @aldenf!

It's maddening how long it's taking mine to travel to me, and I'm holding off from absolute statements until I test it, but... if it's boosting to 5.8V and reducing with PWM calculated at Vavg instead of Vrms, then the lowest Vrms voltage it would be able to output is 4.17V - close enough to a fully charged battery to give the impression that its lower limit is set by battery voltage.

Thanks, Hermit... Great observation! This is what I've been trying to communicate. The iStick is incapable of firing below 4.17 Vrms which is equal to a constant 4.17VDC.

My mail-person delivered today as I was climbing into my vehicle for the airport. My pre-ordered iStick finally arrived. Unfortunately, I find myself out of town for a few weeks without an oscilloscope. But, my handy DMM was packed in my luggage.

I immediately unwrapped the iStick and threw my KFL+ on it for the hour drive to the airport. A displayed 6W fired like 12W. No doubt. When I got to the hotel I tore apart my luggage to set up a little lab on the corner desk. I KNOW my DMM measures PWM in average Volts (Vavg). Sure enough, my meter matched the iStick display at every Voltage level I set, within .05V. Its regulation is actually quite good.

For giggles, I set up both the VTR and VAMO for the same test and found what I expected. For example, @ 3.5V settings: the iStick metered 3.5V, VAMO 1.9V and the VTR 2.2V. This is as I expected. The VAMO & VTR are definitely outputting RMS Voltage (Vrms) and fire different peak Voltage.

I'll do a quick first impression of the iStick tomorrow or the next day. The real takeaway from today is: The iStick is really a 4.2 - 5.5V device. That doesn't necessarily make it bad, just not what the manufacturer claims it to be.

Goodnight all...

 

[TheWestPole]

LMAOF, beautifully said, maybe hyper critical???

Yes, most definitely maybe! That's one of the fun vape-nerdy things we're going to find out. (I'm a sucker for good debate.)

 

[GrumpyEd]

just ordered my 3rd one. one for me, my wife and I will give one to my sister.