In July 2015, I largely approved the Cool Fire IV by Innokin, acknowledging its shape and look. The first time, Innokin corrected an autonomy issue by changing the battery. Now, Innokin proposes this tiny box with exchangeable batteries of 18,650.

Of course, this TC-18,650 keeps the main features of its predecessors. Note that it now shows a max power of 75 W, a value that fits to the commercial target of the device.

The kit also includes a very good atomizer, the iSub V, that works with the excellent Innokin stainless steel resistance coils BVC-coil that are compliant with temperature control features. It also has a good rendering of flavors with the vertical position of its coil.

Innokin kept the last chipset, Aethon, that offers protection against dry hits and a response time of 0.2 second, which allows the coil to be heated more evenly. Of course, this is according to the manufacturer’s specification, but I admit that with a coil resistance of 0.5 Ω, this iSub V provides a vaping of high standard. A bit noisy, aerial but dense.

The Cool Fire IV TC-18,650 is a performant battery box, and not only on paper. The usability is similar to the former models. The weight is still reasonable with 180 g, including the battery.

This version is bursting the Cool Fire IV in the world of the mods with exchangeable batteries. It is, in my opinion, fully deserved when considering the manufacturing quality that offers Innokin. In turn, note that this version looses its USB plug and that it won’t be able to recharge with way. It is to me the small commercial mistake of this box.

A box with a pleasant usability to vape in security

In preambule, the packaging remains identical to the two others. Innokin proposes a comprehensive solution to vape with simplicity with the added value of the excellent iSub V and proprietary coil heads. The offer is declined in a “travel kit” that comprises a transport sleeve equipped a battery tester but not the iSub V.

The finishing is remarkable in this price range, and materials are of high quality. Innokin proposes now products of very good value for money. In this version, the manufacturer has been very attentive to the coating by increasing the number of layers of paint and varnish that gives a soft touch to the product and an overall very good aspect. Innokin also proposes a white version, trendy and appealing, visually. An effort has been made in the choice of colors, and it is appreciated.

It fits the hand extremely well thanks to the bulging that corresponds to the 18,650 battery. The Fire is logically found on its flat side, and still easy to use but strangely more noisy than on the former versions. It is not annoying but noisy enough to pinpoint it.

The controls for power/temperature are below the display and of a classic shape. To remain in the positive visual aspects, the OLED screen and the display remain discreet. No excess, just the basics.

To end, and it’s a first to me, Innokin includes a silicon sleeve for the battery that you can use to protect your spare battery during transport.

Technical review

The main features of this kit are:

  • 1 Rectangular metallic Fire and 2 metallic buttons
  • Variable wattage: 25 W -75 W by increment of 0.5
  • Temperature control mode: Ni (0.1-0.2 Ω), Ti (0.1-0.5 Ω), Stainless Steel 316L (0.2-1.0 Ω).
  • Charge: 5V/2A Fast Charging
  • TempErature: 150-315°C
  • Chipset: control and monitoring of temperature
  • Resistance: >0.1 ohm
  • Threaded 510
  • PWeight: 215 g including iSub V
  • Length: 85 mm, 138 mm including iSub
  • Thickness: 24 mm (20 mm flat side)
  • Resistive wire measurement
  • Protection against short-circuits
  • Battery autonomy indicator (colored LED on the Fire and logo on display)
  • Battery 18,850 not included
  • Dry hit protection
  • Memory of settings (temperature and wattage)
  • Display of Ohm, Voltage and/or wattage while vaping
  • Affichage 3 valeurs, Ohms, voltage et/ou wattage en cours
  • Oled screen
  • Puffs counter
  • Right/left handed mode
  • User manual
  • Battery cap screwed with a retractible handle

iSub V tank’s features:

  • Top filling, quick and practicle
  • Pyrex Tank capacity: 1.8 ml
  • Stainless steel
  • Adjustable Airflow
  • Spare Drip Tip
  • No Spill Coil Swap System

Innokin’s seriousness in manufacturing quality and a simplified temp control mode

At first, it is useful to notice that the user manual is clear and concise, a demonstration that the manufacturer is really concerned by user’s health, especially for the temperature control mode that is efficient at limiting dry hits if not completely eliminating the risk.

Added to that, you will be guided in the different steps of resistance coil calibration. Here, an automatic procedure is applied when selecting the temperature control mode. It is ideal for vapers who do not feel confident with manipulating settings. Each time the atomizer and/or the battery are changed, calibration is set to run automatically. If you are using the same resistance coil, a simple press on the Fire will accept the former settings and skip this step.

In Power mode (Wattage), the settings are still very simple. Press on + or – and get access to the settings. To switch to another mode like Ni, Ti or SS, press both on the Fire and +. It is efficient ans rather simple, finally.

The screen direction for right- or left-handed use can be selected by a long press on + and -, as noticed in the user manual.

For a trumpeting end, I can only acknowledge the smart and easy battery cap closing system, a thread and a spring to cope with any type of battery. A retractible handle is hidden and can be deployed to screw or unscrew the top cap. I have seen many high range boxes that even did not have such a simple but useful system. Congratulations and thank you, Innokin!

The 24 mm thickness is compliant with any type of clearomizer of 24 mm in diameter and lower without altering the visual rendering of the device. It is just fine with the iSub Apex V that comes with the kit and that is also declined in the same colors as the box.

As a reminder, iSub V is equipped with a very performant anti-leak system and is also very efficient at preventing agglutination that often occurs in top-filling devices. This smart system with springs forbids air supply during filling. This bell, added on the central air column, is blocked automatically when the top cap is screwed on the tank. I did not slit everything out to visualize the system but it works pretty well.

This Cool Fire IV will be an excellent introduction to vaping for a beginner and also a good compromise for vaping every day is you already have 18,650 batteries in stock. Its lightweight and usability will sustain many hours of vaping.

 In summary

The “+”:

  • Battery 18,650 interchangeable
  • New chipset Aethon performant
  • User manual
  • Good value for money
  • Lightweight and conpact size
  • Threaded 510 on spring, good manufacturing quality
  • Simplified settings and procedeures
  • Right-/ left-handed mode
  • Travel kit

The “-“:

  • No USB charging and no USB plug
  • Noisy Fire
  • Display not adjustable in brightness
  • LED on Fire not useful
  • Charger and Battery not included
  • Limited tank capacity (3 ml)
  • The dilemna: the travel Kit or the atomizer


Rating of 3.9/5. The possibility to operate with 18,650 interchangeable batteries was missing to the previous versions. It is now possible with the Cool Fire IV TC-18,650. Knowing that it keeps all the assets of its predecessors, simplicity and finishing, it is definitely a good choice

Value for money
Vaping quality
Manufacturing Quality
Previous articleThe documentary film “Beyond the cloud” will be released on September 25, 2016
Next articleHooked, Netted & Landed. A Smokers Story.
Reviewer for the past 3 years, I've tried most of the popular products available on the market. My conclusion about the best vaporizer ? The one that simply fits your need and makes you forget tobacco.
cool-fire-iv-tc-18650-by-innokinThe possibility to operate with 18,650 interchangeable batteries was missing to the previous versions. It is now possible with the Cool Fire IV TC-18,650. Knowing that it keeps all the assets of its predecessors, simplicity and finishing, it is definitely a good choice.
Newest Most Voted
Inline Feedbacks
View all comments
5 years ago

would be nice to have more information on which battery is actually needed. 18650 come in different mh: 2400, 2600. 9600 ….
I have bought 2600mh but can only fire the unit at 11 watts !!!!
we need more info on the choice of battery

5 years ago

220 g. is light weight for you? What are you on??? Also where are you taking your weights from? In all other reviews the box is weighted at 180 battery included. How did you come up with 180 battery excluded? Did you actually weight or just quickly it steal the package-weight from amazon and the alike?