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YiHi SX Mini Q Class Review

Kyle Formeck
July 6, 2016

YiHi SX Mini Q Class Intro

The SX Mini series of mods are well known in the vape world for their high-end chipsets and quality construction. The devices feel great in the hand and the chip allows for more tweakability than any other chip on the market, including the DNA200. Every time YiHi manufactures a new generation of chips, they release a new mod to introduce it. This time, the SX Mini Q Class introduces the SX450J chip. On top of that, this is the first SX Mini mod with a dual battery design which not only increases battery life, it allows the user to fire up to a whopping 200 watts. Let’s dive in to see what else is new with the SX Mini Q Class.

YiHi SX Mini Q Class Specs and Features

Kit Content

  • SX Mini Q Class
  • Micro USB cable
  • User manual
  • Warranty card


  • Powered by the new YiHi SX450J chip
  • Dual 18650 battery device
  • Maximum 200 watt output
  • 16-bit ADC for resistance sampling
  • Buck-boost & boost
  • Output voltage: 1.0 volt - 9.5 volts
  • Temperature range: 212 °F - 572 °F / 100 °C - 300 °C
  • Resistance range:
  • Power Mode: 0.05Ω - 3.0Ω
  • Joule Mode: 0.05Ω - 1.0Ω
  • Supports all TC wire including Stainless Steel
  • Titanium and Ni200
  • Supports all atomizers with SX Pure technology
  • Modes of operation :
  • Powerful+
  • Powerful
  • Standard
  • Soft
  • Eco
  • SXi-Q S1-S5
  • Rotary display
  • OLED screen
  • On-board balanced charging for 2 batteries simultaneously at 2 amps
  • Zinc alloy and stainless steel construction
  • Replaceable covers
  • Spring loaded 510 connector
  • Customize your own logo and menu
  • Intelligent taste control system via SXi-Q
  • Upgradable firmware
  • Protection features:
  • Reverse polarity
  • Output short
  • Low resistance
  • Low battery voltage
  • Overheat & battery overcharge
  • Height: 105 mm
  • Width: 51 mm
  • Thickness: 26 mm

Notable Remarks

Build Quality

YiHi SX Mini Q Class Black

The build quality is on par with what I have come to expect from a mod in the SX Mini line. The batteries fit very nicely and the buttons feel great; they’re clicky without any kind of sponginess to them. The doors are also quite solid and don’t really bend at all. The magnets are nice and strong and hold the doors on very well while still allowing you to take them off without a ton of effort. My only complaint is the tolerances of the doors: they sit flush with the frame so you won’t notice any gaps, but when you grip it tightly and move your fingers up and down, you will feel the doors shift slightly. It’s not a huge deal, but I would’ve preferred the battery tubes from the previous generations where the batteries slide in from the bottom and are held in by screw-in caps. That would’ve eliminated the need for doors altogether. I do understand why they went with the doors though, it makes it simpler to swap batteries.

Hand Feel

YiHi SX Mini Q Class Diamond Blue

The mod feels okay in the hand, but is quite large. This is just my opinion and is most likely due to my small hands and the fact that I’m used to using smaller, single 18650 mods. It is relatively ergonomic, but as not as much as the ML class. However, the slender profile makes it feel comfortable in the pocket. The finish is also a bit slick and doesn’t have the grip that the textured ML class did. It’s not slippery per se, but it could use a little bit of texture to add more friction between the mod and the hand, especially for those hot days when your hands are a little sweaty.

‘Special Features’

One of the most interesting features of the SX Mini Q Class is having the ability to customize the logo and power curves using the SXi software. The ML class also had these features, but required an update as where the Q class can take advantage of these right out of the box. The software may not be the most intuitive to set up, but it is pretty straightforward if you read the instructions provided on YiHi’s site.


YiHi SX Mini Q Class SXIQ

First and foremost is the SXi-Q utility, which allows to users to program five different power curves that are stored in the S1-S5 configurations. It’s pretty straightforward to use and allows you to control the way the you taste your juice. After playing around with a bunch of different settings, I ended up with the configuration seen above for my NarDA built with a single 26g kanthal coil with 8 wraps around a 3mm screwdriver. As you can see, the curve starts off at 28 watts and slowly ramps down over time to 20 watts after about six seconds. This allows the coil to ramp up quickly, but also keeps the heat relatively consistent over the course of a long draw, providing great flavor throughout the entire pull. This is a fantastic feature that is aimed towards more advanced users but it doesn’t come without a few drawbacks. The big one is the fact that you can’t adjust the wattage when using one of these curves. I really wish the points on the curve were percentages instead of power levels to provide greater flexibility in each profile. This would allow the curves to be more generic so they could work in more than one scenario since you can’t adjust the curves without a computer. More of a minor issue is the fact that you can only tweak power levels by a watt, not a tenth of a watt like you can in regular power mode. It may not seem like a big deal, but for someone who almost always vapes under 30 watts, those tenths of a watt make a noticeable difference. For the higher power vaper, this won’t matter too much.

Logo Creator

YiHi SX Mini Q Class Vaping360 Logo

Creating your own logo is another really cool feature of the SX Mini Q class. Using the SXi software, you can import images into the device, allowing you to customize every possible screen you could ever see with the exception of the SX Mini logo that displays when the device boots up. As you can see above, I was able to replace the ‘SX450J’ screen with the Vaping360 logo. If anyone is interested in the logo, you can find it by click this link.


There are five different configurations (C1-C5) that allow you to set everything up to your liking so you can come back to it at a later time (or experiment with other settings without losing your current setup). In each configuration, you can choose the mode of operation (power or joule), temperature, compensation temperature, TCR, power/joules, whether bypass is on and just about everything else on the device. This is a very cool and useful feature for those who change atomizers frequently.

Built-in Power Modes

If using all that software seems a little too complicated, there still is a fair amount of control via five built-in power modes available right from the mods interface.  Here is a rough breakdown of what each mode does:

  • Powerful+ : Increases the power by ~15% for two seconds
  • Powerful: Increases the power by ~10% for two seconds
  • Standard: Runs at the power you set it at
  • Soft: Decreases the power by ~10% for two seconds
  • Eco: Limits the functions of the device in order to save battery life

The powerful modes allow you to overcome ramp up time in large coils that may otherwise get too hot after a short period of time if you simply increased the power.  Soft mode is for those coils that ramp up too quickly and eco mode is there for when you need to squeeze out the most battery life you can get.  All very useful features for different scenarios.


This setting allows you to bypass the regulation altogether and use the device as if it were a mechanical mod. The output voltage is determined by the current voltage of the battery. This can be useful when pulsing out hotspots on a Genisis atomizer.


YiHi SX Mini Q Class Diamond Blue

This mod looks so much better in person than it does in pictures. The pictures I’ve seen online make the finish look like a slick plastic with a solid color. In reality, that is hardly true; the finish is a bit slick, but the color is so much more than a solid shade. It has a subtle sparkle that becomes much more apparent in well-lit surroundings. The instant I took it out of the box, I was impressed at how much detail there is in the finish. On my black version, the dark colored frame also blends very well with the black sparkle finish and creates a very appealing and cohesive look.


YiHi SX Mini Q Class Screen

In power mode, this mod performs very well.  The different modes act as they should and provide more control over how the mod reaches its power level.  There’s not much more to say about this mode, it works exactly as one would expect.

Temperature control mode on the SX Mini Q Class is just phenomenal.  I don’t use any wire other than SS316L for temperature control and if you have any experience with this wire, you’ll know just how finicky it can be.  With 8 wraps of 26g SS316L around a 3mm screwdriver on a NarDA, the build comes out to around 0.54 ohms.  Firing that at 22.1 Joules and 400 °F with a compensation temperature of 70 °F and a TCR value of 0.00089, the vape is extremely smooth.  I have had issues with some chips holding the temperature constant with SS316L wire, but this mod keeps the temperature steady without any noticeable choppiness or fluctuations.  I can’t really say that it’s any better than the SX Mini ML class since the temperature control on that was also superb, but it definitely beats the DNA200 in this aspect.

I found that in practice, the SXi-Q modes are very nice and if you set them up right, it can definitely improve your vape experience.  You do want to be careful not to have to drastic of power level changes since it can make the vape choppy, but if you stick with a smooth curve designed to fix an issue (overcome ramp up time or to tame heat over the period of a long draw), you’ll find these modes can be very useful.


  • Fantastic temperature control, even with SS316L wire
  • SXi-Q modes provide a lot of customizability to your vape experience
  • Configurations allow you to easily swap between different atomizers without needing to set it up again
  • Dual 18650 design increases battery life and maximum power output
  • SXi software is an awesome tool for upgrading the firmware and customization
  • 200 watts should be enough for just about everyone
  • 0.5Ω minimum resistance allows for a ton of leeway for crazy builds
  • Custom logo creator is a nice addition


  • Battery doors don’t fit as perfectly as they could
  • Slick finish doesn’t feel as nice as the textured finish of the ML class
  • Can’t adjust the power levels in the S1-S5 modes
  • Need a computer to program the S1-S5 modes


The SX Mini Q Class is worthy addition to the fantastic line of SX Mini mods. It is essentially the big brother of them all in every way: it houses two 18650 batteries, fires up to 200 watts and down to 0.05Ω and not to mention, it is the largest of them as well. With all of that said, the SX450J chip doesn’t seem to be much of an upgrade since it doesn’t introduce any features that the SX350J v2 doesn’t have with the latest firmware update. If you’ve always wanted a SX Mini mod but never bought one because 75 watts wasn’t enough or the 0.10Ω limit was too high, then this mod was practically designed for you. If you enjoyed the previous SX Mini mods but found that a single 18650 battery wasn’t enough, you should seriously consider this mod. If you don’t fall into the previous categories, then you want to pass on this one. All in all, I think the SX450J is a nice, albeit minor, upgrade to my favorite chip on the market.

My name is Kyle and I have been vaping for almost a year now. I started vaping to kick my 9 year smoking habit and got hooked on trying to get the best flavor out of my atomizers. I am a software developer living in upstate NY and in my free time I like to write shoegaze and dream pop music.
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7 years ago

Fine review, good Sir. I’m very much enjoying mine. This is the YiHi reference mod I’ve always wanted. I’m generally a dual-18650 or 26650 vaper. Curiously, the board for the SX450 chip is quite long; I’m not confident that we’ll see as many high-end modders making sweet boxes with this chip.

Kyle Formeck
Kyle Formeck
7 years ago
Reply to  RPadTV

Thanks Ray! I don’t think we’ll see many high-end SX450 mods either since most modders like to keep their designs compact and that’s just not possible with a dual 18650 design. What I’d love to see is some stabwood replacement doors for this thing, that would be pretty awesome.

Ed Jagla aka. (JazzyJag)
Ed Jagla aka. (JazzyJag)
7 years ago
Reply to  Kyle Formeck

Unfortunately with all the tight fine lines and curves the SXMini Q class has it wouldn’t be practicable producing stabwood doors/panels.

Kyle Formeck
Kyle Formeck
7 years ago

I can see that, maybe some damascus, timascus or mokume then!?!

7 years ago
Reply to  Kyle Formeck

I’m going to see if my friend can make some doors with ink patina. Hopefully it works!

Kyle Formeck
Kyle Formeck
7 years ago
Reply to  RPadTV

If it works out, let me know; I’d be willing to pay for sick new set of doors!

Min Seo-yun
Min Seo-yun
7 years ago

Great review! Appreciate if you can share the rest (s1-s5) of your flavor curve settings.
Have been experimenting this for way too long and yet to achieve any success 🙁
Thank you in advance

Kyle Formeck
Kyle Formeck
7 years ago
Reply to  Min Seo-yun

I didn’t set all of the other configurations, only two or three of them. I’d say the best approach would be to find what wattage you like most with whatever build you’re using. From there, determine what issues you have with your build in standard power mode; i.e. too much ramp up time, too much heat over the course of a long draw etc. There needs to be a problem that you’re trying to solve, otherwise, the SXi-Q curves aren’t going to make the vape any better. With the specific build I mentioned in the review, the issue was too… Read more »

Toni ShamelessTrouble
Toni ShamelessTrouble
7 years ago
Reply to  Kyle Formeck

I dont think you need to be “fixing a problem” to use the modes. I use mine because I like a cooler initial hit but for it to heat up a little at the end, like it did while smoking a cigarette. I vape at around 65w and my curve is -3w to +5 in a pretty straight line up to 5 seconds (I usually hit my mod for about 4 seconds but I ramp it up to 5 – then have a straight line the rest of the way across.

Ed Jagla aka. (JazzyJag)
Ed Jagla aka. (JazzyJag)
7 years ago

Hey Kyle, I’d to welcome you to my SXMini Brotherhood group, it’s a great group of owners of YIHI, SXMINI, SX350J V1&V2, SX450J and other custom built devices. https://www.facebook.com/groups/SXMiniBrotherhood/

Kyle Formeck
Kyle Formeck
7 years ago

@JazzyJag:disqus, thanks for the invite but I’m already a member of that group 🙂 I loved my SX Mini ML class so much that I looked for an owners group on FB and found that one, nice work!

Toni ShamelessTrouble
Toni ShamelessTrouble
7 years ago

Really great review, very detailed – and I like how you explain things out so well – thanks!