iStick by EleafUS

I finally got my hands one one and I must say this thing is amazing, so much power in such a tiny little package! Still trying to wrap my head around this "step down" stuff. I'm vaping on the Rose V2 with a 1.4 ohm 28g build that I was running on the SVD at 11 watts, on the iStick I get a better experience at 7.5 Watts. The iStick is also doing a better job at heating the coil up quicker. Weirdly I'm getting much better flavour on this :confused:

What an amazing little thingie :D

10393894_10205237402156128_995534811806008990_n.jpg
 
I finally got my hands one one and I must say this thing is amazing, so much power in such a tiny little package! Still trying to wrap my head around this "step down" stuff. I'm vaping on the Rose V2 with a 1.4 ohm 28g build that I was running on the SVD at 11 watts, on the iStick I get a better experience at 7.5 Watts. The iStick is also doing a better job at heating the coil up quicker. Weirdly I'm getting much better flavour on this :confused:

What an amazing little thingie :D

View attachment 16140
See PBusardo's review for the reason.
 
I can see myself packing the trusted SVDs away pretty soon, but they do look pretty badass compared to the iStick, it would actually be a bit more comfortable if it was ever so slightly bigger, I feel like a lobster holding this little thing.
 
I finally got my hands one one and I must say this thing is amazing, so much power in such a tiny little package! Still trying to wrap my head around this "step down" stuff. I'm vaping on the Rose V2 with a 1.4 ohm 28g build that I was running on the SVD at 11 watts, on the iStick I get a better experience at 7.5 Watts. The iStick is also doing a better job at heating the coil up quicker. Weirdly I'm getting much better flavour on this :confused:

What an amazing little thingie :D

View attachment 16140

Hi @BumbleBee - glad you liking the iStick!
Lovely

As far as I understand (from the PBusardo video) the iStick's measurements use the average voltage - whereas most other devices like the SVD use RMS Voltage. The average voltage is lower than the RMS. Same applies to Power.

So to compare the iStick to the SVD for example, the iStick will need to be set to a lower setting.

I was looking for a simple way to convert from Average to RMS.
I found the following site with a nifty calculator:
http://www.learningaboutelectronics.com/Articles/Voltage-rms-calculator.php

They also have a nice little description:
RMS voltage is a method of representing an AC voltage waveform in which the RMS value specifies the amount of DC voltage that will produce the same heating effect, or power dissipation, in a circuit, that the AC signal would over its entire cycle.
Thus, the RMS value is a very important value when comparing AC signals to DC signals, in that they both produce the same amount of heating in a circuit and cause the same amount of dissipation of power.


Back to your example:

Using that simple calculator site, the RMS voltage is 1.1107 times higher than the Average. So the factor to convert is 1.1107. Something tells me this may be an oversimplification because surely the frequency of the modulation needs to also be taken into account? Nevertheless, let us assume this factor is right. Let's apply it to your example.

On the SVD, your Rose has a resistance of 1.4 ohms and you set it on a power of 11 Watts. That translates to a Voltage of 3.92V. This is a RMS Voltage since we suspect the SVD uses RMS readings.

To get the same "effect" on the iStick, one would expect to set it to 3.53V (3.92/1.1107). I.e. the equivalent in Average Voltage terms, just dividing by that factor. This would then equate to a power of 8.9 Watts, or about 20% lower than the power setting on the SVD.

Incidentally, since Power= V squared/R, the 1.1107 factor above for Voltage means that at the same resistance, converting from Average power to RMS power means a factor of 1.234. So Power (RMS) = 1.234 x Power (Average). Of course, this only applies if this simple conversion factor is correct.

It is interesting that you are using a setting of 7.5 Watts on the iStick, which is lower than the suggested equivalent from our simple calculation above. Maybe the type of modulation it uses is different, leading to a perceived stronger hit. Or maybe the calculation above is too simplistic.

I find similar results to you @BumbleBee. My Evod runs at 7.5 Watts on my MVP. When I put it on the iStick, my calculation above suggests about 6 Watts (7.5/1.234). Yet when I put it on 6 Watts, it feels more powerful. I need to do more testing with different atties.

On another note, this may suggest that the iStick is capable of more than 20 Watts RMS. At 20 Watts Average it is likely pushing around 24.6 Watts RMS. So in usual vaping terminology, it may actually be a 24.6 Watt device ;-)

Perhaps some of the experienced electronics buffs can comment here. My main concern is the simplistic conversion factor of 1.1107 from average to RMS voltage.
 
Hi @BumbleBee - glad you liking the iStick!
Lovely

As far as I understand (from the PBusardo video) the iStick's measurements use the average voltage - whereas most other devices like the SVD use RMS Voltage. The average voltage is lower than the RMS. Same applies to Power.

So to compare the iStick to the SVD for example, the iStick will need to be set to a lower setting.

I was looking for a simple way to convert from Average to RMS.
I found the following site with a nifty calculator:
http://www.learningaboutelectronics.com/Articles/Voltage-rms-calculator.php

They also have a nice little description:
RMS voltage is a method of representing an AC voltage waveform in which the RMS value specifies the amount of DC voltage that will produce the same heating effect, or power dissipation, in a circuit, that the AC signal would over its entire cycle.
Thus, the RMS value is a very important value when comparing AC signals to DC signals, in that they both produce the same amount of heating in a circuit and cause the same amount of dissipation of power.


Back to your example:

Using that simple calculator site, the RMS voltage is 1.1107 times higher than the Average. So the factor to convert is 1.1107. Something tells me this may be an oversimplification because surely the frequency of the modulation needs to also be taken into account? Nevertheless, let us assume this factor is right. Let's apply it to your example.

On the SVD, your Rose has a resistance of 1.4 ohms and you set it on a power of 11 Watts. That translates to a Voltage of 3.92V. This is a RMS Voltage since we suspect the SVD uses RMS readings.

To get the same "effect" on the iStick, one would expect to set it to 3.53V (3.92/1.1107). I.e. the equivalent in Average Voltage terms, just dividing by that factor. This would then equate to a power of 8.9 Watts, or about 20% lower than the power setting on the SVD.

Incidentally, since Power= V squared/R, the 1.1107 factor above for Voltage means that at the same resistance, converting from Average power to RMS power means a factor of 1.234. So Power (RMS) = 1.234 x Power (Average). Of course, this only applies if this simple conversion factor is correct.

It is interesting that you are using a setting of 7.5 Watts on the iStick, which is lower than the suggested equivalent from our simple calculation above. Maybe the type of modulation it uses is different, leading to a perceived stronger hit. Or maybe the calculation above is too simplistic.

I find similar results to you @BumbleBee. My Evod runs at 7.5 Watts on my MVP. When I put it on the iStick, my calculation above suggests about 6 Watts (7.5/1.234). Yet when I put it on 6 Watts, it feels more powerful. I need to do more testing with different atties.

On another note, this may suggest that the iStick is capable of more than 20 Watts RMS. At 20 Watts Average it is likely pushing around 24.6 Watts RMS. So in usual vaping terminology, it may actually be a 24.6 Watt device ;-)

Perhaps some of the experienced electronics buffs can comment here. My main concern is the simplistic conversion factor of 1.1107 from average to RMS voltage.
Way too complex for me. And you have to factor in that as the battery runs down the difference becomes smaller! Much easier to do it just by feel.
 
Way too complex for me. And you have to factor in that as the battery runs down the difference becomes smaller! Much easier to do it just by feel.

Agreed @Andre - it is complex.

I wonder why eLeaf chose to do it like this and not stick with the traditional RMS reading.
Maybe there is a good reason. Who knows.
 
That makes good sense @Silver, could also explain why the battery mileage is so good with the iStick. I am going to agree with @Andre though, when you started using the numeric keypad I started getting a bit lost. When I first used this little thing I remembered folks talking about running much lower power settings so I hooked up an atty and dialed the iStick right down and tried it, turning it up gradually until it felt right.

Another thing.... I tried my Kayfun on it, I have a 1.1 ohm micro coil in there running all day on the SVD at 11W, chain vaping with no problems. On the iStick at it's lowest setting of 8.1W I get a dry hit on the first toot. So it looks like I will have to change my builds for this device, maybe another wrap or two with a bigger ID to accommodate more wicking. I'm using 28g on a 2mm ID with rayon.
 
Either way, the battery lasts me 2 days, and I just use the lowest watts that accommodates my current ohms(1.2 - 1.4), oh and I love the look of it with the Atomic :D with excellent vapour as well 8--)

IMG_20141125_153300.jpg
 
Agreed @Andre - it is complex.

I wonder why eLeaf chose to do it like this and not stick with the traditional RMS reading.
Maybe there is a good reason. Who knows.
I'm guessing that they chose this setup because the circuity is more compact and appears to delivers more power than a device using RMS
 
That makes good sense @Silver, could also explain why the battery mileage is so good with the iStick. I am going to agree with @Andre though, when you started using the numeric keypad I started getting a bit lost. When I first used this little thing I remembered folks talking about running much lower power settings so I hooked up an atty and dialed the iStick right down and tried it, turning it up gradually until it felt right.

Another thing.... I tried my Kayfun on it, I have a 1.1 ohm micro coil in there running all day on the SVD at 11W, chain vaping with no problems. On the iStick at it's lowest setting of 8.1W I get a dry hit on the first toot. So it looks like I will have to change my builds for this device, maybe another wrap or two with a bigger ID to accommodate more wicking. I'm using 28g on a 2mm ID with rayon.
I also had an issue with burnt hit with my kayfun on the istick. What ended up working for me was a spaced out coil versus my usual compressed "micro" coil, I also use a 2mm ID with rayon wick. I haven't had a dry hit in days now :dance:
 
I also had an issue with burnt hit with my kayfun on the istick. What ended up working for me was a spaced out coil versus my usual compressed "micro" coil, I also use a 2mm ID with rayon wick. I haven't had a dry hit in days now :dance:
Good to know

I will stretch this coil out a little and see if that makes a difference, thanks for the tip ;)
 
That makes good sense @Silver, could also explain why the battery mileage is so good with the iStick. I am going to agree with @Andre though, when you started using the numeric keypad I started getting a bit lost. When I first used this little thing I remembered folks talking about running much lower power settings so I hooked up an atty and dialed the iStick right down and tried it, turning it up gradually until it felt right.

Another thing.... I tried my Kayfun on it, I have a 1.1 ohm micro coil in there running all day on the SVD at 11W, chain vaping with no problems. On the iStick at it's lowest setting of 8.1W I get a dry hit on the first toot. So it looks like I will have to change my builds for this device, maybe another wrap or two with a bigger ID to accommodate more wicking. I'm using 28g on a 2mm ID with rayon.
The higher the resistance of your coil, the lower the power you can get on the iStick. Choose the Eleaf iStick on this site (courtesy of @JW Flynn) to see what they recommend - seems to me 1.5 ohms for the widest range of power.
 
The iStick performs really well using a dual coil that is in the 1.0-1.2Ohm range on the Kayfun. I run my dual coil Kayfun build (1.1Ohm) at 20W and it rocks - no dry hits at all and intense flavour. Of course, it's a bit of a pain to build, but really worth it for use with the iStick.

You can see my dual coil Kayfun build here.
 
The higher the resistance of your coil, the lower the power you can get on the iStick. Choose the Eleaf iStick on this site (courtesy of @JW Flynn) to see what they recommend - seems to me 1.5 ohms for the widest range of power.
That is pretty cool, I wouldn't have spotted that on the site if you guys didn't point it out, thanks ;)
 
No probs, would love to hear if it works for you too ;)
So far so good @Dubz, I spread the coil out a little and rewicked, it was burned in the middle. Too much heat concentrated in a very small space I think, the spaced coil should slow that down quite a bit. I've built a few spaced coils before and they worked quite well but have been doing tight microcoils lately for some reason, thanks for reminding me how nice spaced coils work ;)
 
Just ordered 2 for family members. Total came to 1300 and it includes 4 days shipping and also comes with Kangertech Aerotank MOW for each iStick.

Heavengifts.com running their special.

Good Deal.
 
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