Today I’m taking a look at the SX Mini SL Class V2. I’ve got history with Yihi and the SX Mini having purchased the original around three years ago. Yup! The upgrade has been a while in the making.

sl class v2 banner

The Yihi chip is as prolific as the Voopoo Gene or the Evolv DNA and like those, has its friends and foes. As to why? I couldn’t really say. I always think that as long as a Mod is reliable, efficient and carries out the tasks set upon it by the chip it’s doing the job.

It all began in 2014 when Yihi introduced the SX Mini brand to the world. It was a time of great enthusiasm and innovation. The team at Yihi were highly set on developing new ideas upon the world of vaping.

SL Class V2 hand check picIt wasn’t long before they were winning multiple awards and joining forces with the likes of renowned supercar company, Bugatti to produce the Bugatti e-cigarette which did nothing to harm their growing reputation.

Many established vapers will be familiar with the SX Mini G (red our the latest SX MINI G Class V2 review), T and X Class range of dual battery mods whereas the SL range relies on a single 18650, 20700 or 21700 battery.

So I mentioned that I’ve got history with the Mod. There was something the design that bugged the life out of me.

Let’s find out if the upgrade resolves the issue.

What Can We Expect From The SX Mini SL Class V2?

The chipset has been upgraded to the Yihi SX730J and includes a fourth generation temperature control suite. Now constructed from a durable zinc alloy, expect the Mod to weigh slightly less than the class v2 features

The same joystick control is used to navigate the menu functions. The display has been changed and the viewing window is larger.

Expect faster internal charging times as the SL Class V2 ditches Micro USB in favour of Type C.

The Mod is capable of handling sub ohm tanks, RDA’s and RTA’s of anything up to 28mm in diameter.

Don’t expect Buck Boost or Bypass mode with the upgrade. They haven’t made it across from the original SL Class.

SL Class V2 boxed image

SXmini SL Class V2 – Inside the Box

The dimensions of the box are identical to the original, giving an early indication of similar size.

  • SXmini SL Class V2 Mod
  • User manual
  • Type C USB charging cable
  • Warranty card

SL Class V2 unboxing image

SXmini SL Class V2 – Key Features

The Mod uses a single external battery. A 18650 can be used with the included adaptor, ideal for running coils with less demanded resistances. 20700 or 21700 batteries will take care of Stainless Steel or Nichrome coils when using temperature control.

With an output range of 5-100W, the SXmini SL Class V2 will be fully compatible with Sub Ohm Tanks, RTA’s and RDA’s.

There are multiple different user modes via an updated waterproof circuit board – including…

Three pre-determined power settings are incorporated, designed to boost flavour quality. There’s also an option of tweaking them to personal taste.

An IPS-Farb colour display now takes the place of TFT with the upgrade.

All the usual safety features are included such as reverse polarity, low resistance and low voltage protection.

The SXmini SL Class V2 is available in Mystic Grey, Gunmetal Tang, Copper Brown, Black Tang and the colour under review, Black Silver.

SXmini SL Class V2 – Specifications

  • Size: 89.1 x 42.3 x 30.2mm
  • Battery: Single 18650/20700/21700 (not included)
  • Output: 5-100W
  • Modes: VW, VV, Temperature Control, Intelligent Curves, Flavour Modes
  • Resistance range: 0.15 – 3.0ohm (VW mode) / 0.1 – 3.0ohm (TC mode)
  • Flavour mode: Soft, Normal, Strong, SXi EQ1, SXi EQ2, SXi EQ3
  • Max charge: 5V/1A Type C
  • Output current: 3.1A – 32A
  • Input current: 1.4A – 30A
  • Screen size: 0.96in IPS colour
  • Thread: 510
  • YIHI SX730 chipset
  • 28mm diameter tank compatible
  • Waterproof chipset

SXmini SL Class V2 – Design and Build Quality

As I’m already in ownership of the original, we’ll be taking a look at the key differences in design, build and overall performance.

Main Body

To begin with the SL Class V2 has a much more organic, free flowing design. The cylindrical exterior is enclosed inside a C shape frame and the board and screen no longer look like they’ve been bolted onto the front.

SL Class V2 comparison pic 4 side view image
Left = SL Class V2, Right = SL Class V1

This does mean the presence of a few Torx drive screws but they don’t affect the overall appearance. It’s a vast improvement, in my opinion.

I’m not overstruck on the “SXmini” plate that’s driven into the spine because it reminds me of a dog tag. I understand that it’s for branding but still an unnecessary inclusion.

SL Class V2 rear view image with logo

I received the Black Silver version. The tubing is smooth but also has a subtle wood grain texture running vertically.

There are fewer squared off edges to contend with now. Its less ‘Lego-like’ shall we say. This makes the upgrade much more comfortable and ergonomic during day to day use.

Knurling and Threading

The heavy knurling of the original has been dropped. In fact it’s absent around the 510 plate which is now smooth and polished. The spring loaded 510 pin is once again centre loaded and will accommodate the same atomiser sizes as before.

SL Class V2 comparison pic 3 top down image of 510 connectors
The SXmini SL Class V2 is a smooth operator in comparison to its older sibling

Now for my bug bear. The threading and action on the battery cap. I found it notoriously crunchy and difficult to thread on the original.

Much to my relief it’s been significantly improved on the upgrade. The cap isn’t as thick and incorporates micro knurling as opposed the large and cumbersome design of the original

SL Class V2 threaded battery cap comparisonThe ease of use is made possible by male threading on the cap itself. There’s less chance of stripping and it’s much easier to remove or replace.

SL Class V2 battery screw cap and threads image

The polished alloy finish on the battery cap mirrors that of the 510 connector plate. The cap also has the same number of venting holes as the original. Very pleasing to see.

SL Class V2 comparison pic 1 battery capFront Panel and Display

The fire button is more or less in the same position and roughly the same size and shape. The action of the SL Class V2 button is less spongy and makes a distinctly audible click when pressed.

Although the screen area looks bigger, both use a 0.96in colour screen. The screen on the original Mod was recessed which protected it from damage if dropped.

It sits flush on the upgrade so that’s a potential area of weakness in terms of build.

SL Class V2 screen comparison with OG image

The IPS colour display is considerably sharper, less blurred and easier to read. Useful for tired, weary eyes – like mine!

..In case you’re wondering IPS stands for In-Plane Switching. It simply means that colours appear more accurate under narrow viewing angles.

What has been recessed is the joystick button. It protrudes considerably less which should prevent getting caught up in a bag or pocket. Damage prevention also extends to the Type C USB charging port.

An improvement on the one hand – not so much on the other.

How To Operate The SXmini SL Class V2 Mod

Five clicks of the fire button will turn the device on. It’s not that simple when turning the device off, however.

  • Press the fire button five times. This will activate the menu screen.

Select ‘System Off’ before pressing the joystick button in. Once this has been done, the ‘shutdown’ option must be selected before the SL Class V2 will ‘thank you’ before powering down.

..Kind of reminds me of my PC. Not sure if that’s a good thing or not! lol

SL Class V2 shut down screen option

The menu screen also includes a host of other options.

  • Mode select – Select between wattage, temperature control or variable voltage
  • Puff counter – Display manual or lifetime count. There’s also the option to reset the counter
  • Tweaks – Alter the screen brightness, restore factory settings, adjust average room temperature, auto power (on/off)
  • Stats – This displays the firmware and version of the chipset
  • Show temperature in Celsius or Fahrenheit
  • Screen timeout – Anywhere between 15 – 90 seconds

You can also access the menu screen by holding the joystick to the right for 3 seconds.

To lock or unlock the device hit the fire button three times. It is not possible to vape while the device is locked.

Push the joystick to the left to return to any previous screen.

Home Screen

SL Class V2 main screen display in wattage mode
The home screen in wattage mode

When the SL Class V2 starts up for the first time the home screen will display standard wattage mode.

From top to bottom, left to right the following information is displayed.

  • Battery meter
  • Current curve pattern
  • Battery percentage
  • Puff counter
  • Power mode (wattage, voltage or temperature control)
  • Installed coil resistance
  • Curve graph
  • Current voltage
  • Output current

Voltage Mode

Hold the joystick to the right for three seconds to enter the menu screen. Use the joystick to highlight the mode option and select V. Volt (variable voltage).

Press the joystick left to return to the home screen.

It’s not mentioned in the instruction manual so here’s how to adjust the voltage.

  • SL Class V2 how to adjust the voltage in variable voltage modeOn the home screen press the joystick button in.
  • Push the joystick up or down to adjust voltage. Wattage is shown in the bottom left hand corner of the screen and will also adjust in accordance to the applied voltage.
  • Press the fire button to lock the current voltage

It’s also worth mentioning the same method of adjustment applies to wattage and temperature control mode.

Smart Power Curve Mode

It’s possible to tweak power output to suit individual vaping requirements. To do this, push the joystick button down when on the home screen.

Select from Neutral, Soft, Strong or three user defined settings

  • While the text is highlighted in red, press the joystick button up or down to change the setting
SL Class V2 changing the initial power curve setting to strong
The power bars can be individually edited to suit personal vaping requirements using the SXi EQ settings.
  • Press the joystick button in to choose an option (text turns yellow)
  • Scroll down to exit or wait until the Mod automatically returns to the home screen

If using the predetermined settings, Soft mode will gradually increase the power from 75% to 100%.

The Neutral setting constantly holds power at 100%

The Strong setting boosts power briefly to 125% before returning to 100%.

Up Close And Personal With Power Curve

The SXi option allows you to personalise up to three power curves.

  • Press down on the joystick to enter the curves screen
  • Select one of the three SXi EQ options
  • Use the ‘edit’ option to begin making individual adjustments to each power bar
SL Class V2 SXi EQ mode personalised power curve settings image
Me messing around with the power curve for the SXi EQ1 setting.

A total of 20 bars can be adjusted between 0 – 150% power and each one represents 0.5 seconds of vape time.

Once the power curve has been manually applied the Yihi chip calculates the Overall wattage/power output.

Hit the fire button to return to the home screen.

Temperature Control Settings

SL Class V2 temperature control menu screenTo enter temperature control settings, press the fire button five times or hold the joystick right for three seconds.

Scroll down to ‘mode’ and select it by pressing the joystick in. Temperature control offers dynamic and constant wire settings. Dynamic allows the temperature to fluctuate slightly while constant maintains a strict temperature limit.

To start using temperature control mode the coil resistance must be registered and locked while in its room temperature state.

Having chosen or locked in either Ni200 or SS316L as a coil material the device will automatically return to the home screen after a few seconds.

Pressing the fire button or nudging the joystick left will have the same effect.

Under temperature control the home screen offers further tweaking.

  • Press the joystick button twice to select a cold, cool, normal, warm or hot vape. The voltage and temperature in Celsius or Fahrenheit automatically adjusts.
  • The individual parameters for the above vaping temperatures can be tweaked further by pushing the joystick right.
  • On the home screen highlight the coil resistance to use a new or old one.
  • On the home screen highlight the coil material to quickly change between Ni200 or SS316L
Tweaking temperature control settings on the home screen
Tweaking temperature control settings from the home screen.

SXmini SL Class V2 – How Does It Perform?

I don’t do temperature control as I don’t own any SS316L or Ni200 coils. For this reason I’ve omitted those tests.

Instead I tested the Mod in standard wattage mode first. That’s the default mode straight out of the box.

My Hellvape Dead Rabbit V2 RDA was used running dual Wotofo fused Clapton coils at 0.14ohm.

SL Class V2 running in wattage modeI was previously using a dual 18650 battery mod at 75W so tested the SL Class V2 at the same output. It had significant clout behind it when using a single Molicel 21700.

The performance was equally as good as the dual 18650 Mod I’d been using.

There was very little ramp up time using the Nichrome (Ni80) coils. The performance was excellent and I noticed very little degradation as the battery depleted.

In fact when switching to a high drain 18650 Vapcell K25 the same applied. The only thing of difference was the battery life itself. I managed 11 hours from the Molicel 21700 and five hours using the Vapcell 18650.

Variable Voltage Mode

Switching attention across to voltage mode, the chip was reading 3.25V as an equivalent to the 75W previously tested.

SL Class V2 running in voltage modeI personally think this mode improves on wattage for instantaneous output to the coil as well as overall power efficiency. The vaping temperature felt more consistent.

Flavour seemed to take less time to pull through. The heat generated from the coil was more consistent across longer inhales.

Voltage mode also made it much easier to find the desired sweet spot.

Power Curve Settings

I can’t say I noticed a great deal of difference between the Soft, Neutral and Strong pre-sets. I’m not likely to use Soft mode anyway because I prefer a swift ramp up when using an RDA.

SL Class V2 running in SXi 1 user defined power curve modePower curve settings are best suited to those that are going to make the most of the twenty bars available. The adjustments will be more significant over an increased inhale. My lungs just aren’t that strong anymore! lol

For those that are, I suggest increasing or decreasing across the full number of bars. For example, the pre-sets offer only a 2.5 second fluctuation in power. That’s not really enough to be of any effect.

So power curve does work well but over a longer duration – that’s just something to keep in mind.


  • More ergonomic and comfortable to hold than the original
  • The design has been radically improved
  • Battery screw cap threading is no longer an issue
  • Display is much sharper, clearer and easier to read
  • Improved battery management


  • Erratic battery reading on occasion
  • Remains quite a heavy Mod
  • The chip gets confused between locking or displaying the menu screen
  • Functionality may take some getting used to (subjective)
  • Powering down is a drawn out affair

SXmini SL Class V2 – Final Review Verdict

It’s always the little things with me. Things that don’t get mentioned in instruction books. For example, being able to reset the puff counter while the chip retains the total number for the lifetime of the Mod.

It’s reassuring to see equivalent wattage whilst using voltage mode. For someone taking the leap across from standard wattage to voltage mode it’s ideal.

I love how the SX730J calculates required wattage when tinkering with DIY power curves.

That’s just the kind of attention to detail Yihi have provided with the SX730J chip.

I’m not the biggest fan when it comes to powering down the Mod. It’s been thrown in with the menu screen and since the menu screen can be accessed with a nudge on the joystick why not have the usual five clicks to turn the device off?

SL Class V2 front view imageThe biggest surprise for me was at how well the SXmini SL Class V2 handled an 18650 battery. It gave me a few hours more vaping time than I was expecting and performed remarkably well even during discharge.

The design, build and screen quality have all had an overhaul for the better although the weight is still there. It is a solid bit of kit, that’s for sure.

When it comes to performance there’s nothing I can dumb down about the Mod. Put simply it does the job and it does it reliably and consistently well.

These were the requirements I was looking for at the top of the review and the SXmini SL Class V2 hasn’t let me down.

That’s the main reason the Yihi chip will always have more friends than foes.

Have you used the SXmini SL Class V2? Let us know what you think in the comments below!

neil cozens
Neil Cozens

My name is Neil and I've been a keen vaper for eight years, having been smoke free since 2014. That's all thanks to being introduced to a CE4 clearomiser by a work mate. In 2015 I started a Facebook group encouraging members to help others make the switch, sharing thoughts and opinions while acknowledging all the hard work that goes into running a vape shop and the guidance those folks give. I've also created a You Tube channel, Ncboreas Vapes. It's primarily there to help the newer vaper so if you've any questions feel free to drop by! There are so many positives to vaping and absolutely none to smoking. It's a message I continue to spread. Long Live Vaping. Live Longer Vaping.

Build Quality
Ease of use
Overall Performance
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My name is Neil and I've been a keen vaper for eight years, having been smoke free since 2014. That's all thanks to being introduced to a CE4 clearomiser by a work mate. In 2015 I started a Facebook group encouraging members to help others make the switch, sharing thoughts and opinions while acknowledging all the hard work that goes into running a vape shop and the guidance those folks give. I've also created a You Tube channel, Ncboreas Vapes. It's primarily there to help the newer vaper so if you've any questions feel free to drop by! There are so many positives to vaping and absolutely none to smoking. It's a message I continue to spread. Long Live Vaping. Live Longer Vaping.
yihi-sx-mini-sl-class-v2-reviewI think the Yihi SX730J chip does a better job over the original when it comes to battery management. It constantly appears to be optimising the vape experience and that's always a good thing. The screen quality is vastly superior, the aesthetics and ergonomics enhanced and the overall power capabilities across the various modes tested are very impressive. Oh! and the threaded battery cap is no longer a pain in the proverbial..


  1. Really very beautiful, but with many errors: battery percentage, and manual puff count always going to zero… the battery cuts out too soon, at about 3.3v low battery appears

  2. Not firmware upgradable, there’s a bug in the TC setting, battery percentage bug, the screen is too dim outside, the plastic trim was cracking on early devices, early devices have an older firmware to that of later models. One step forward in terms of design, two steps back on the v1.


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