Coi M1 Vivi Nova Tank in Shiny Steel

Coi Cigs was the subject of a review on this site not too long ago (you can see that one here).  While for the most part, the company focuses on eGo-style kits, they have a couple of interesting surprises hidden within their site.  One of those surprises is their M1 e-cigarette tank.  It’s a stainless steel tank with an interesting design. It looks like a fancy RBA, but it actually houses a Vivi Nova-style system inside.  Read the review to find out more.

Disclosure: I received this product from Coi at no charge for review purposes.
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coi m1 tank review card image.jpg Product name M1 Tank
Available from  Coi e-Cigarettes
Price  $12.99
Construction  Stainless Steel
Competing products  Smok Pyrex Nova, Trophy Tank
Who’s it for?  eGo users looking for a durable tank

See more photos on Google+
Visit Coi for options and prices


M1 Tank Review

The M1 Tank has a really cool appearance on the outside. It’s a mid-size tank, slightly more narrow than something like a ProTank, but bigger than the mini version of the Pro. The body is all metal, with no viewing windows of any kind.

coi m1 tank review full body image.jpgNaturally, this is both a benefit and a drawback.  On the plus side, you can run the most acidic e-liquid you can find without fear of the tank cracking.  You can probably drop it on cement too without much worry.  But the obvious negative is that you also can’t see the amount of e-liquid in there at any given time.

Going back to the appearance for a moment, the top of the tank appears to have a drip tip that tapers down at the base going into a top cap with a couple of stair steps increasing in size.  Actually, there is no drip tip.  That is all one piece, and it unscrews for filling access to the tank.

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The tank body has a little taper out from the top 1/3 until it reaches the widest part of the rest of the tank body.  There’s some slots and inverted chevrons notched in the side.  It almost looks as if they were punch-outs and could have served as the window for liquid viewing.

Finally, there’s the bottom cap. It has a dimples all around the outside edge to dress it up. Otherwise, it functions like any other Vivi Nova bottom cap, housing the battery connector and the bottom stem that goes into the tank.  The removable head section screws on to the stem inside the tank.

coi m1 tank review take apart image.jpgI always get confused as to who’s Nova design is what. This particular head is the one that has the little metal spike that sits on top of the head. The silicone gasket goes over both parts. When the top cap of the M1 is screwed into place, it seals against that gasket, preventing e-liquid from escaping the top.  The wicks are single thick wicks.

Filling the tank is slightly challenging.  The point at which the internal head meets the side of the tank is fairly narrow.  This means when removing the top cap for filling, there’s not a whole lot of room.  A needle tip bottle, or a very steady hand with a standard dripper bottle are in order to get filled up.

The lack of transparency in the body also means you have to play filling by ear.  You have to watch for liquid to start to appear right at the top of the head gasket. There’s another arguement for filling slowly right there.

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Coi M1 Tank Performance

Considering this is a Vivi Nova, there’s already a performance hit from the start as compared to the more popular CE5 and bottom coil clearomizers. Novas have always had a bit of a problem wicking, and I found that the thicker wick versions in particular can be tricky.

coi m1 tank review on bauway itouch battery.jpgNot being able to see how much e-liquid remains is also a recipe for running out of liquid at the end of a tank and experiencing dry burns.

There’s actually two different ways the performance went for me. It depended on how I used the tank.  I used it both with my Coi battery, which is a single voltage eGo style device.  Then I used it with my Innokin MVP as well.

When I run stuff at variable wattage I tend to have a little bit of a lead foot.  I always try to crank the power up. Frankly, that just doesn’t work terribly well with this device.  I found that unraveling the wick so that it was essentially a bunch of smaller wicks helped a bit.  Nova heads are also fairly easy to re-wick with cotton, or rebuild your own heads.  I thought about going that route, but for this review, I considered it cheating and refrained myself.

Of course, running the tank on the Coi rig was a different story.  There was no problems at all with the wicking keeping up with the fixed 3.7 volt output of the battery.  Normally, that sort of thing leaves me feeling a little underwhelmed.

Really, the experience wasn’t that bad running on the smaller setup.  Vapor production was admirable considering how low the power output was (the tank has a resistance around 2.6 ohm, so we’re talking about wattages in the 5 watt range).

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Naturally it wasn’t the kind of performance that would wow me, but it was pleasant and inline with similar eGo setups.  I could also use my favorite e-liquid, a notorious tank cracker, which I often can’t do on smaller setups.

In general, I was pleased with the performance.  It’s great for those who use lower wattage setups or people who already have a single voltage eGo setup like the Coi units.  If you plan on throwing a lot of power at this tank, you should think again.

Or, be prepared to rewick or rebuild the coil.  It would probably be pretty darn good after that.

coi m1 review tldr

Too Long; Didn’t Read

The Coi M1 is a Vivi Nova housed in a tank that looks like a hard-core RBA atomizer.  The design is beautiful, even if not being able to see your e-liquid is kind of a bummer.  Unfortunately, the Vivi Nova design is better suited for fixed-voltage eGos and not high-power variable wattage setups.  However, if you’re ok with rebuilding the head, you can probably get a pretty solid little setup going.

You can get one of these at Coicig’s website.


  • Beautiful design
  • Tough tank
  • Good performance on the Coi battery


  • Can’t see e-liquid
  • Poor performance at higher wattages

Steve K

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