Last Updated on June 15, 2017 by Team Spinfuel

Our Preview of the Sigelei Fuchai Duo-3 was just about 3 weeks ago, and in that time, we’ve put in many hours of vaping with this mod and various sub-ohm tanks. After carefully considering the quality of build, the value ($49.95 at Element Vape) –  and the performance of the 175W box mod, we’re confident that this review will reveal its true worth, and the expectations of its potential owners.

It should also be noted that Sigelei is a name that draws immediate suspicion with almost a third of the Vapers in the vape community. Sigelei lost some trust with users over the debacle that was the initial Fuchai 213 and how it calculated temperature in TC mode. We don’t review every device that comes from Sigelei, but we don’t have any trust issues with them either. Reviewing the Duo-3, we did so with eyes open.

Note* The Fuchai Duo-3 offers a 2-Cover model that utilizes a 3rd 18650 battery for a maximum wattage output of 255W. We did not receive this 2nd cover, so we cannot speak to this model, or how it changes the device for better or worse. If the times comes to review this version, we will. In the meantime, a short video that shows this 3rd battery cover option.


About The Sigelei Fuchai Duo-3 TC Box Mod

Sigelei Fuchai Duo-3 175W TC Box Mod Full Review - Spinfuel VAPE

The Fuchai Duo-3 is constructed with a Zinc Alloy for durability, while still maintaining a soft touch contour chassis that feels very natural when holding it. The key to the best comfort is choosing the right sub-ohm tank or RDA/RDTA, you won’t want to stack a huge SMOK TFV12 Cloud Beast King, or iJoy MAXO V12 on top. Not because there isn’t enough wattage, or that it can’t handle the ultra-low resistances of some of the replacement coil choices, but only because the Fuchai Duo-3 looks best, and feels most balanced, with a tank the size of the SMOK TFV8 Big Baby, or ProCore Aries, and even the MELO 300.  We used each of the above, and they all performed well, but the larger tanks through this nicely engineered box mod off balance.

Measuring 85mm (5.1”) by 42mm (2.5”) by 30mm (1.8”), the Fuchai Duo-3 comes very close to the ideal size of a modern box mod. It’s bright, clear TFT Color Display offers all the information you need to set the device to your precise settings. The adjustment buttons are located directly below the display, and the slightly oversized firing button is located above the display.

Sigelei Fuchai Duo-3 175W TC Box Mod uses a fully upgradeable and advanced chipset. In addition to the Variable Wattage output of up to 175W, it offers an all-inclusive temperature control suite for those that continue to use temperature control coils. I spent a day with the Fuchai Duo-3 using the SS316 coils that are found in the Uwell Crown 3, and found the TC abilities to be on par with any others. Most of the last 3 weeks were spent with Kanthal/Cotton coils.

The Real World Report

Sigelei Fuchai Duo-3 175W TC Box Mod Full Review - Spinfuel VAPE

We received several of the Fuchai Duo-3 box mod, in various colors. The mod is available in Red (mine), Black, Gun Metal, Blue, Gold, and Silver. No one on the staff discovered any issues with their device, including misfires or coil shorts.

Many, if not most, box mods will falter at times, depending on various factors, including the type of atomizer and coil used with it. A misfire is the most common. You’ll notice a misfire when you press the Fire Button and nothing happens. Release the button, press again, and it fires normally. This is the typical misfire and it happens quite a bit.

The HCigar VT250S for example, will display an error such as “Ohms too High”, or “Atomizer Short” when using the SMOK TFV12 Cloud Beast King with its most powerful coil, the V12-T12 Duodenary replacement coil.

The Sigelei Fuchai Duo-3 has no such problems, from any of the staff users. During my time, I mainly focused my use of the Duo-3 on using it with the SMOK TFV8 Big Baby with my favorite replacement coil, the 0.15ohm V8 Baby-T8 Octuple Coil, vaping at 90+ Watts, and the Joyetech ProCore Aries with its 0.4Ω ProC1 Atomizer Coil at 60-75W. I found the best performance with these tanks, but as you know, the tank and/or coil is the most important part of the vape experience anyway, so this could very well be my personal tank preferences more than the box mod’s performance. Admittedly, I was surprised that no one, myself included, reported any momentary misfires. That is an excellent indicator of the value of the Fuchai Duo-3.

Fuchai Duo-3 Battery Door – Important


Sigelei Fuchai Duo-3 175W TC Box Mod Full Review - Spinfuel VAPE

Since discussing the Fuchai Duo-3 in various forums I’ve learned that same people are talking about battery wiggle in their unit. John’s wife says the same thing; the battery compartment seems just a hair too big, and the full battery back door plate is difficult to lock it. There are easy solutions to these fixable issues.

As far as the battery wiggle goes, if you have this issue, we did not, watch this video on a quick fix.

Also, there is a very small lip at the top of the battery door, and to lock in the battery door you’ll need to set the lip into its space on the device. If you don’t the door won’t lock. At times, the device won’t even power on unless the door is firmly attached and locked in.


Spinfuel Staff Input

Before I sat down to write my real world experience I asked the others to provide a paragraph that would accurately describe their experience with the Fuchai Duo-3.

Julia: When it comes to Sigelei you really don’t know what to expect from each product release. Sometimes the devices are wonderful, sometimes they have issues, so while agreeing to put down one of my favorite box mods to use the Fuchai Duo-3 in its place, I was not sure what to expect.

The Fuchai Duo-3 feels wonderful to hold, and the full color display seems to lend credence to this new trend toward full color displays. We’re seeing more and more of them of late, including the Evolv DNA mods; the DNA75C and soon the DNA250C. The Duo-3 is nothing if not up to date.

While I’m not sure I will never pick up the box mod I laid down to use the Fuchai Duo-3 I do know I’ve decided to keep the Duo-3 in my rotation of mods. Definitely a good device from Sigelei this time out, and the price is excellent for this dual 18650 175W TC box mod.

John: I have no complaints with the Fuchai Duo-3. It functioned exactly as advertised, and as I talked about with Tom, it never misfired. That’s definitely a positive thing to consider. Having said this, my wife Lisa LOVES IT. I mean, this is someone who changes her mods more than anyone I know, but 3 weeks ago she picked up her Duo-3 and hasn’t used anything else since. Lisa’s tank of choice is ProCore Aries with the Direct Lung 0.4Ω coil, and the combination, in her words, are “perfect”.

Jason: My first thought when I began using the Fuchai Duo-3 was how disappointed I was with my new Lost Vape Therion DNA75C. Both device are dual 18650, both have full color displays, and one outputs 175W while the other a measly 75W. And the Therion is more than twice the cost. Aesthetically, the Therion DNA75C is far more attractive, and probably better built, but the Fuchai Duo-3 is no slouch. It’s a good size, with a good finish to it, and when I want to vape at 100W or more, I have a feeling I’ll continue to pick up the Duo-3. For under $50, this is a great device.


As you can see from the list of Features and Specs below, the Fuchai Duo-3 is well spec’d and a modern, forward thinking box mod. Sigelei did a wonderful job with this one, and it’s $49.95 price tag is certainly fair. That’s not to say that Sigelei will hit it out of the park every time, but this time they came very, very close.

Available now in all colors, the Sigelei Fuchai Duo-3 is $49.95 at Element Vape.

Tom McBride

Sigelei Fuchai Duo-3 175W TC Box Mod Features:

  • Dual 18650 High-Amp Battery – Not Included
  • Wattage Output Range: 10-175W
  • Voltage Output Range: 1-7.5V
  • Min Atomizer Resistance: 0.1ohm
  • Intuitive 1 Inch OLED Display – Full Color Resolution
  • Ni200, Titanium, and Stainless Steel Compatibility
  • Temperature Coefficient of Resistance (TCR) Adjustments
  • Temperature Factor of Resistivity (TFR) Adjustments
  • User-Friendly Preset Modes
  • High-Grade Zinc Alloy Construction
  • Three-Button Operation
  • Large Oversized Firing button
  • Removable Battery Cover – Lock Switch- Press In to Release
  • Reverse Battery Protection
  • Low Resistance Protection
  • Battery Imbalance Protection
  • Low Input Voltage Warning
  • Short Circuit Protection
  • Overheat Protection
  • MicroUSB Port – Firmware Upgrades
  • Spring-Loaded 510 Connection