Innokin Cool Fire IV Review


After recently reviewing a big power variable wattage mod, a temperature controlled mod, and a regulated bottomfeeder mod, it’s nice to get back to the basics. Sometimes simple is good. In the fast paced world of vaping technology and the quest for more power, it’s easy to forget not everyone needs or wants a gigawatt device, removable batteries, or temperature limiting. Don’t get me wrong, I’m a huge fan of all those things but I’m also a fan of well executed simplicity – and not many device manufacturers accomplish that quite like Innokin. My first mod after graduating from eGo style batteries was the venerable Innokin MVP 2.0. It was rugged, simple, and reliable. Innokin has since released several subsequent versions of the MVP, all sharing those same traits. Not forgotten among all the MVP versions was the Cool Fire. The latest iteration, the Cool Fire IV, is the subject of this review. The Cool Fire IV is a regulated, variable voltage, variable wattage “box” mod with a built in battery.

The Innokin Cool Fire IV used for this review was provided by VaporDNA. The Cool Fire IV is available in black, blue, emerald green, gold, pink, purple, red, and silver.

The Packaging and Included Stuff

The Cool Fire IV arrives in a clear plastic clam shell box, typical of most Innokin packaging. Included in the box are the device, USB-to-microUSB charging cable, eGo adapter, user manual, and two Innokin stickers. The user manual and stickers are located under the foam insert which has a pull tab for easy removal. And, speaking of the user manual, it is excellent. It is clearly written and very thorough. One of the better user manuals I’ve seen, for sure. The back of the box enumerates the Cool Fire IV specifications and features.


The box has a scratch-off authentication code to verify you received a genuine Innokin product.


The Cool Fire IV carries a 90 day warranty which is serviced by two US based service centers, located in North Carolina and California.

Innokin Cool Fire IV Specifications:

  • Operating Voltage: 3.0V-7.5 V (adjustable in 0.1V increments)
  • Operating Wattage: 6.0W-40W (adjustable in 0.5W increments)
  • Battery Capacity: 2000mAh
  • Standby current: 100uA max
  • Maximum output Wattage: 40W
  • Maximum output Current: 12A
  • Maximum output Voltage: 7.5 V
  • Minimum atomizer resistance: 0.3Ω (according to the box and web site – manual states 0.2Ω)
  • Charging: Micro USB DC5V/1A


  • Battery Level Indicator:
    The Cool Fire IV battery capacity is displayed via green, yellow and red LED lights.
    Green = Almost fully Charged. When the Cool Fire4 is fully recharged the LED light will power off.
    Yellow = Half Power.
    Red = Low Power. Charge the Cool Fire IV
  • Variable Voltage:
    Voltage can be adjusted from 3.0 – 7.5 volts in .1 volt increments.
  • Variable Wattage:
    Wattage can be adjusted from 6.0 – 40.0 Watts in .5 watts increments
  • ON/OFF Battery Switch
  • Spring loaded 510 pin
  • 15 second cutoff
  • Ability to flip screen orientation
  • Low Voltage Warning
  • Short Circuit/Atomizer Protection
  • Over-Discharge Protection
  • ‘Vape while charging’ Technology
  • Remembers last Voltage or Wattage setting
  • Overheat Protection

Build Quality and Ergonomics

Okay, let’s get this out of the way first thing – the Innokin Cool Fire IV is beautifully constructed. I’ve owned mods costing 10 times more than the Cool Fire IV which weren’t built nearly as well. The thing just *feels* like quality. I’m not sure if the device is constructed of all aluminum or stainless steel and aluminum but it’s solid, that’s for sure. I’d wager the Cool Fire IV will take a lot of abuse.

The fit and finish are excellent. The body of the device has a very nice brushed finish with vent holes on one side and an embedded Cool Fire IV logo on the other. The top of the frame has a lanyard ring above the firing button. The power switch is located on the bottom of the device and the front features the microUSB charging port, firing button, and voltage/wattage adjustment buttons. I really like the on/off switch and wish more mods had a hardware switch to control device power. The only negative I can find is the adjustment buttons are a bit rattly. The screen, while small, is clear, bright and relatively easy to read.


In addition to being incredibly well made, the Cool Fire IV feels great in hand. The brushed finish feels very nice and the device is easy fire either with your index finger or thumb, depending on how you hold it. The buttons all have a nice tactile click and are well located.

The Cool Fire IV is also pretty darn small. Innokin lists the device as 86mm tall. The Cool Fire IV should be suitable for any size hands and, again, is extremely comfortable to hold and use due to its shape and diminutive size. At the time I took the pictures for this review, the only other device I had by which to make a size comparison is the Pioneer4You IPV4. The IPV4 is a pretty large device but hopefully you can gauge the relative size of the Cool Fire IV from these shots.


In summary, the Cool Fire IV has exceptional build quality and is very comfortable to use. I can’t emphasize enough how impressed I am with the construction of this device especially considering its price point. There are more than a few manufacturers who would do well to emulate Innokin’s quality manufacturing… I’m looking at you Pioneer4You and Sigelei. While P4Y and Sigelei construct decent quality devices, they aren’t even in the same league as Innokin, especially when compared to the Cool Fire IV.

And, as always, looks are subjective but I think the Cool Fire IV is a very nice looking device. The brushed finish looks refined and I like the almost C-frame like appearance. It is certainly a refreshing departure from the typical “boxy” box mod.

Usage and Performance

The Cool Fire IV should, by default, arrive with the power switch in the “off” position. Simply flip the switch to “on” to power up the device. To lock or unlock the device, click the fire button three times.

The Cool Fire IV will operate either as a variable voltage (VV) device or a variable wattage (VW) device. I used the Cool Fire IV nearly exclusively in variable wattage mode. To toggle modes, press and hold the firing button and the “+” adjustment button for VW mode or the “-” adjustment button for VV mode.

While in VV mode, the display will show your selected voltage as the primary value and in VW mode, your selected wattage. Also displayed on the screen is your atomizer resistance, the secondary power value, and the battery life indicator. While firing, the display will show a “puff counter”, measured to 1/10th of a second.


Wattage and voltage are adjusted using the “+” and “-” buttons. Press and hold the desired button until the wattage or voltage value flashes. Press again to adjust the setting. Pressing and holding the adjustment button will accelerate the setting changes. The settings do round-robin when either the minimum or maximum values are reached. Once at your desired setting, press the firing button one time to lock in your setting. The voltage setting increments by 0.1V while the wattage increments by 0.5W.

To flip the screen orientation, press and hold the “+” and “-” simultaneously until the screen flips.

The firing button is surrounded by three small LED lights – green, yellow, and red to indicate the battery charge level. From the Cool Fire IV specifications:

“Green = Almost fully Charged. When the Cool Fire4 is fully recharged the LED light will power off.
Yellow = Half Power.
Red = Low Power. Charge the Cool Fire IV”

To charge the Cool Fire IV, connect the microUSB end of the charging cable to your device and the USB end to either a computer’s USB port or a suitable wall adapter. The Cool Fire IV has a 1A onboard battery charger and it charges rather quickly. The device also has pass-through charging, allowing you to vape while the device is charging.

So, it looks good, is built like a tank, and is easy to use. Does the performance live up to its other outstanding qualities? It sure does. I’ve been using the Cool Fire IV for several weeks and I love this little thing. It doesn’t exactly dovetail with my preferred vaping methods (I’m a die-hard bottomfeeder) but it had no trouble finding a spot in my rotation. I used the Cool Fire IV with several different atomizers built to different resistances and all worked well (with a caveat, which I’ll explain shortly). Every atomizer I tried on the Cool Fire IV sat flush. I primarily used my Ehpro Billow V2, Avid Vaper Marquis, and Origen V3 by Norbert. The Cool Fire IV has no problem powering a dripper or rebuildable tank atomizer. I suspect it would also perform very well with the plethora of sub-ohm clearomizers on the market when used with a 0.5Ω or higher coil head. Additionally, it would be a very good option to power other clearomizers such as an Aspire Nautilus or Kanger Protank.


I typically ran the Cool Fire IV between 22W and 40W depending on the atomizer I was using at the time. It performed very well for all my “real world” usage. It reads atomizer resistance very accurately and displays it to the 1/100th of an ohm, which is nice. It also fires very accurately in most cases. It does have some trouble regulating with a very low resistance atomizer. The user manual states the device uses direct current (DC) and pulse width modulation (PWM). In my brief testing, I did experience the Cool Fire IV switching to PWM mode as you’ll see below. My inline voltmeter adds a very small amount of resistance (~0.02Ω) and I used the resistance values with the meter attached for this table.


With a 1.40Ω atomizer, the Cool Fire IV was pretty darn accurate. Not dead on, but pretty close. With a 0.33Ω atomizer, the device struggled a bit to properly regulate. The device kicked into PWM mode in an attempt to regulate the power at 10W and 20W. I’m not sure where the DC/PWM threshold is but I’m guessing probably around 3V. Additionally, the Cool Fire IV could not regulate accurately enough at 30W and 40W to deliver the requested power.

I’d suggest 0.5Ω-1.2Ω as the sweet spot for the Cool Fire IV (note the 1.40Ω atomizer is requiring nearly the device’s maximum specified output voltage of 7.5V). As always, you’ll want to build your coils or use pre-made coil heads which cater to your device’s specifications and limitations. Although the user manual claims the Cool Fire IV will fire a 0.2Ω coil, it’s not going to regulate it very well. I don’t view this a huge issue – again, use coil resistances which fit with the device’s optimal operating parameters.

All in all, I’d consider the performance of the Cool Fire IV to be very good when used with an appropriate atomizer resistance.


Bottom line on the Innokin Cool Fire IV? I think it’s a winner – a big winner. The build quality is phenomenal, it looks cool, and it performs very well. I didn’t experience the first problem with the device. It’s also small and super comfortable to handle and use. My complaints with the Cool Fire IV are few and relatively minor. The rattly adjustment buttons don’t bother me to any great degree. Likewise, the problems the Cool Fire IV demonstrated trying to properly regulate with a very low resistance atomizer can be easily avoided by building to the device’s strength or using a pre-build coil head with a resistance of 0.5Ω or higher.

The Cool Fire IV is a great option for someone looking for a very inexpensive, moderately powered, easy to use, and rugged device. At the Cool Fire IV’s price point, I’m not sure there’s a better value on the market today. And, it comes in a bunch of cool colors!



  • ​Superb build quality
  • check
    Compact size
  • check
    ​Comfortable to handle and use
  • check
    Simple operation
  • check
    Very good performance


  • ​Rattly buttons
  • ​Inaccurate regulation with low resistance atomizers

8 thoughts on “Innokin Cool Fire IV Review”

  1. Help….I bought my f first box mod the cool fire IV….I have one problem and not sure what to do…I originally had the tank .5 ohm that was color coded to the unit which was also plastic….when I take a draw it pops like a darn firecracker……tank after a week leaked like a sieve so I returned it and bought the Atlantis .5 ohm have not tried this one yet…….what would cause this crazy pop? It is not as bad as you draw on it more but if you set it Dow for a while before using again it starts again……It is set at 14 watts

    1. Baley Pepper

      I hav experienced what you are deceiving also I have the cool fire IV and have a subtank mini with the .5 ohm coil heads and it works perfect between 20 and 25 watts the popping in my experience is the wattage is being set to low

  2. The cool fire IV won’t hold a charge for more than several hours, certainly not for a whole day. I would not buy this device again unless the battery power was extended to at least 2600 mah. Then I would buy several. My buttons do not rattle, and I really like the volts/watts going down low enough to use a non sub ohm tank if needed.

  3. The Cool Fire IV is rated at 2000 mah meaning it will not last a full day fully charged. I would not buy this device again unless the mah was bumped up to at least 2600 mah. My buttons don’t rattle, and I like the volts/watts being low enough to throw a non sub ohm tank on the device if necessary.

  4. I love my cool fire IV.I have no problems with my charge.I can use it for a week without having to recharge.I choose to use it on VV.I set it at3.8 and get excellent vapor from it. Plus I recharge it when the light turns yellow.I will definitely be buying another one.I have an anyvape tank on it and get excellent results.
    Pam Lyles

  5. Phil Jackson

    I have owned the cool fire 4 since the beginning of September and I am very impressed with its performance thus far. I use the aspire Nautilus mini with a 1.6 ohm coil at 12-13 watts and it typically lasts me 6 to 8 hours of heavy vaping, 6-8 ml of ejuice. I recently purchased the Sense Herakles and use the .5 ohm coil in it at 30 watts and I get around 3 hours and 8ml of e juice before I recharge. For myself, this is a wonderful mid level box mod. It fits my hand nicely and into my pockets without being to bulky. The only thing I can speak of as a negative is that it does not have a removable battery. I see this device as a great item for taking along to run errands where a sub ohm tank is attached or an 8 hour workday with a 1.6 ohm tank. Very pleasant device for the money spent!

  6. Athanasios Labrakis

    It was a nice base until it stopped working. I left it in the car empty for a week, Since then it just kept saying too hot, and when its battery discharged, it would not charge when I pluged it in. Just a bit past my 90 day warranty, company refusing to send me another or refund me.

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