My first comment, when I received the CoolFire IV from Innokin to review just a little over one month ago now, was, best design I’ve seen from you guys since the introduction of the VTR. And six weeks on, after using it on a daily basis I’m sticking by those first impressions.

Yes, it has all the functionality and reliable performance we have come to expect from Innokin, but this time with a touch of real class in its appearance, size, and choice of colours.

Firing a large range of tank resistances from 0.2Ω all the way up to 3.1Ω and from 6W up to a maximum 40W in a compact size of only 3.93”. The CoolFire IV is a very impressive little performer that you’re going to find very hard to put down I can assure you!


Remove the outer shrink wrapping along with the decorative cardboard sleeve and you will find the resistant plastic casing with the CoolFire IV inside.

Detach the two stickers that hold the upper lid closed, to access your CoolFire IV device along with an ego 510 threaded adapter, USB charging cable. You will also find inside located underneath the foam housing a manual and Innokin stickers.

The rear contains an overview of the products features, so be sure to read this entirely including the age and health warning before purchasing it.


What’s new

The Cool Fire IV battery capacity is displayed via green, yellow and red LED lights.
Green = Almost Fully Charged. When the CoolFire IV is fully recharged, the LED light will power off.
Yellow = Half Power.
Red = Low Power. Charge the Cool Fire IV
Voltage can be adjusted from 3.0 – 7.5 volts in .1-volt increments.
The wattage can be adjusted from 6.0W – 40.0 Watts in increments of .5 watts
ON/OFF Battery Switch
Saftey15 second cut off
Includes a Bright OLED  flip screen with reverse orientation
Low Voltage Warning
Overheat Protection
Short Circuit/Atomizer Protection
Over-Discharge Protection
Vape while charging Technology
It also remembers your last Voltage or Wattage settings


Technical Specifications

Operating Voltage: 3.0V-7.5 V
Operating Wattage: 6.0W-40W
Battery: Internal 2000mAh
Standby current: 100uA max
Maximum Output Wattage: 40W
Maximum Output Current: 12A
Maximum Output Voltage: 7.5 V
Clearomizer Resistance: 0.3 Ohm (Recommend)
Charging: Micro USB DC5V/1A

Function & Performance

I have used the ranges supplied in this chart to test the CoolFire IV’s full range, from 6 watts all the way up to its maximum of 40 watts. I have also used the iSub G, along with the Smok VTC Pro, and three different E-juices with varying PG/VG mixtures from Space Jam, Cuttwood, and Mystique to gauge its overall performance for you.

REACH compliant

If you intend to use this range of E-Liquids, please make sure they meet the current requirements set out by your countries regulatory bodies.
For EU countries, more information on this can be found here along with REACH’s partner agencies from around the globe.

E-Liquids may contain diacetyl (DA) and acetyl propionyl (AP) or other carcinogenic ingredients or disease-causing substances, so please be aware of this and seek medical advice before using any of the products used in my reviews.

People can suffer from allergies to chemicals that may be present in the makeup of certain types of E-liquids or produced in their vapour. People can become sensitive to, or even allergic to Nickel or Titanium used in Temperature Controlled designed coils. Again, please be aware of this and seek medical advice before using any of the products used in my reviews. Also, check with your E-liquid supplier or the equipment manufacturers directly before purchase and use.

You might find this range of calculators provided by Steam Engine particularly useful, so thank you to Lars for allowing me to include them in my reviews. These calculators are currently under development, and the information that they contain may change at any time without notice. Please read the How It Works section for a more in-depth understanding. And never leave your device charging unattended, make sure you are using the recommended battery for your device, and always remember, SAFETY FIRST.

Potential Polycarbonate problems

It is well known that certain e-liquid ingredients can cause cracking or even melting of polycarbonate plastic or acrylic tanks and tubes. For further information on this subject, please check with your E-juice supplier or contact the manufacturer directly.



The CoolFire IV is a very well designed compact device packed with the latest technology that looks good and sits comfortably in the palm of your hand.

It’s 510 connector has a spring loaded positive pin made with durable stainless steel threading allowing for flush mounting of a wide variety of different tanks with an ego thread adapter also included.

The CoolFire IV uses OLED clear bright technology found on recent models from the Innokin range making it easy to see and adjust your settings to an orientation that suits you best. The display shows the resistance of the attached coil, current voltage, (adjustable in increments of 0.1) along with the wattage, (adjustable in increments of 0.5) using the three well placed and very comfortable buttons. You also have a visual display of the device’s current battery charge which appears to be reasonably accurate.

What I love about Innokin’s products is the degree of accuracy and safety measures that are included in their designs. This is what they say.

The Cool Fire IV uses Vrms DC current being very accurate with a power deviation of only 0.1Watt. The full 40 Watts is precisely maintained between resistances of 0.3 to 2.5 Ohms. Therefore, you have no wasted power, and exact accuracy means you are always vaping at the power level you choose. Vrms provides superior precision in delivering the correct wattage Ohm’s Law requires and stable power means better vapour.



I’m going to keep this part of the review short and sweet just like the quick overview of the CoolFire IV due to time constraints.

It appears that Innokin have finally struck gold with this latest edition, and I would be amazed if this does not become the biggest selling product in their range for 2015.

There is very little not to like about it if anything at all. The performance was excellent as is the wealth of technology and safety features included in its design, in a size and choice of well-suited colours that is sure to please.

Comfort is assured due to the smooth satin finish and rounded edges in a weight that is comfortable to hold, and it’s also very pleasing to the eye. The performance with both the iSub G and Smok VTC Pro at the ranges tested provided great vapour and flavour as well.

The only consideration I would have is a version with a removable battery option that some people may prefer?

Expected price range appears to be around the £40.00 or $48.00 mark.

For further details on the CoolFire IV or any other Innokin product, please visit the Innokin website or contact your local brick and mortar store.

To View The User Manual: Click  Here

Thanks to Innokin for providing the Technical specifications for this review and Images of the CoolFire IV

All products are sent directly by the manufacturer for review


Copyright © 2015 Vape On Watt Reviews

All rights reserved. No part of this publication may be reproduced, distributed, or transmitted in any form or by any means, including photocopying, recording, or other electronic or mechanical methods, without the prior written permission of the publisher, except in the case of brief quotations embodied in critical reviews and certain other non-commercial uses permitted by copyright law. For permission requests, write to the publisher addressed “Attention: Permissions Coordinator.


Join the conversation! 55 Comments

  1. hi i just bougt a cool fire 4 and i have it for 4 weeks now and is smell like burn and dosent want to turn on

  2. Hey!
    Love my cool fire IV but I keep getting a message telling me to check atomizer when I turn on.. But I don’t know how nor what it is. Please help. It’s not hitting like it used to 🙁

  3. Hi there I’ve had my cool fire for now 3 or more months and I am confused hopefully you can help me, I’m on 3.5v and 20 watts but I’d like to have it more up as im smoking far to much, but as I turn it up it just burns the coil straight out and I don’t understand why? I let the liquid soak into the coil , Why have 40 watts on it when you can’t even turn it up to it? Please help

    Many thanks scott

  4. Hey, so I’ve just bought my innokin coolfire IV, and I’ve used the scratch test thing to ensure its a proper innokin product which it is! But I don’t know if it’s charging or not (first time vaping/using this device) how long should the first ever charging session be and how do I know if it’s charging or not (it’s plugged in using the cable that was provided and using my phones charging plug, but I don’t see any signs of charging, any help guys?

    • Aminah, when you plug it in to charge, the small LED light should come on – amber or green. Once it reaches full charge, the light goes off.

    • For some reason the charge status doesn’t update on the coolfire 4 unless you leave the bottom switch in the ON position. So leave it ON, click 3 times to lock it and charge it until the green light goes off. Around 4 hours if it was empty.

  5. Great technical review, I like this product very much. Functional, simple, quality!

  6. The first time that I have had beer without a cigarette in 30 years, what a fantastic product, I have tried electronic cigarettes and even hypnosis, I only ever smoked when drinking beer, but could not enjoy a beer without a cigarette. I am using a coffee e liquid and can only say that I am astounded with the satisfaction that it has given me, with no craving for a cigarette, no bad breath or aftertaste in the morning, no smell and it actually tastes really nice. I cannot believe just how good this is, very excited about quitting smoking at last ! it is much cheaper, but that is not really my issue, as I only smoked about 30 cigarettes a week. Incidentally the product is reassuringly quite weighty and well built, very we’ll engineered and looks expensive, overall, I am absolutely delighted !!!

  7. If you feel burning or electric smell while vaping you definetly need to change the coil only cost around 2-3 quid

  8. Hi there… been into my local cigara store to ask what i need to help me get off normal bacci.. they advised me to get one of these.. they said it great value and the best one they sell for my reasons anyway.. after reading your write up it has made me confirm what they have said.. so i am off to get one in the next few days…. great review write up by the way .. thanx stu

  9. Can I leave my cool fire 4 on charge night without it blowing up?

  10. My question for the coolfire 4 plus is if I’m vaping on watts do I need to set the correct volts aswell or or do I not need to mess with the volts and vice versa ?

  11. Hi , Loved mine at first but now the tank is leaking .. Liquid runs out of air vent as soon as I put liquid in , so I’ve only been adding enough to enjoy 1 vaping session at a time .. Bit of a pain but worth it as I love this machine , any ideas or do I just get a different tank ?

    • Hi, I am having the same problems. No idea what to do about it but it is using liquid so fast, refilling several times a day. Using the genie top. Look forward to responses to this as I am not sure if it could be user error. Also is it best to store it on its side or upright? Sorry for two comments forgot to set email alert

    • I’m having the same issue! Have you gotten a response on the issue? Plus every now and then when I go to vap I just get air like it is turned off, after a few tries it does automatically turn off. I have it set to 23 w.

  12. Hope you can help im going crazy with my Coolfire IV!
    I brought it one month ago now and ive taken it back to the shop 5 times with having major problems with the coils burning out, they have changed the coils 6 times and tried different things but it keeps burning!
    I brought a coil on Saturday just gone and its lasted 4 days, ive never had a full week off one coil! its costing me a fortune and driving me nuts as i love the vapour and given up smoking now for over 5 weeks..

    Please help?

    • I’m having exactly the same problem. Have you got to the bottom of it yet?

    • I have the same problem only worse. I am lucky to get a whole day with a coil and, as you said, it is costing a fortune. When I ask about this at the Innevape store where I got it the only answers I get are, “well, the coils do need to be changed on all tanks”, “That never happens to us and we use these tanks as our testers” and lastly, “I don’t know what to tell you”.

  13. Hi,Ive just bought the Coolfire IV, Was wondering which eliquid is best to use,as ive been adviced to use the proper cloud liquid.
    Please can anyone let me know where i can purchase this from
    as im a heavy smoker i was told to use no higher then 6mg,but i want tobacco flavour


  14. I have had the Cool Fire 4 for a few days now and after playing with the settings I would recommend to start with 23.0 watts, 3.3 volts and leave the ohms somewhere low approximately 0.47. With these settings you get maximum flavour, vapour and not such a hard hit on your throat.

  15. Hi can any 1 help me I just got cool Fire Iv plus and I dunno wat watts and volts to use cuz every time I put it above 3.0v it’s taste like burnt? So ive set it to 2.8volts and 21.0watts and still not getting the best flavour?

  16. ive just got the cool fire iv plus and its turning my eliquid brown
    can some one advise on best settings and how to stop this please

  17. I’ve just brought a cool fire 1V and l can change the volts and the wattage settings but for some reason l can’t get into change the ohms I’ve tryed just about everything it doesn’t matter what buttons I press in what order I just can’t get in to change it and it’s frustrating me can someone please help.

  18. Hi. I’ve got CF4 and Aspire Nautilus Mini. Occasionaly coil resistance jumps up to 3-4 Ohms and taste smells burnt. Is it coil problem or CF4?

  19. Only had my Cool Fire IV since Saturday and when I press button to vape it makes a crackle/pop sound. What’s wrong with it? Thanks

  20. I have the cool fire 5, it is totally awesome. I use I constantly and no complaints what so ever in 4 weeks I have charged it once. Its a must have. I was going through the pen styled vaps like normal cigarettes cost me a fortune weekly as they burnt out easily. My coolfire 5 is yes a bit more expensive but worth every penny spent.

  21. Hi,
    My cool fire 6 plus is leaking all the time. I’ve only had it a week or 2. It seems to be leaking at the bottom of the tank were you can open the valve. It’s really disappointing as I like this product so much. Please help why us it leaking..

  22. Hi there I recently bout a cool fire IV and I have a few questions I’m hoping someone can help me with I put oil into it the other day and it’s went from a orange colour to a dark cola colour? It still tastes ok I just don’t get why it’s doing that as never had them problems with my tendura t 18? I only have it at 25 w and same with volts? Can any one tell me a decent setting to put it on? Thanks

  23. Hi can u use any type of e-liquid on the cool fire

  24. What oil is best for my cool fire iv?

  25. My Cool Fire IV plus turns itself off all the time. I can have a puff and go to have another but it has switched off and I have to press 3 time to turn it back on. Why is it doing this?

  26. Has cool fire IV got overheating protection

  27. What causes it to blow back when inhaling. It nearl blew my head off!! Was’nt expecting that..

  28. Was wondering what the purpose of the spirals tank was as it fits where the dual core should go, is this another style like the wicked ones, just seems pointless to have put into box if it has no purpose

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.