SD Keychain Stock

SD Keychain review: Lots of power, tiny e-cigarette

SD Keychain Stock


If you have spent any time browsing e-cigarette reviews on this site, you know that electronic cigarettes come in all shapes and sizes.  One of the newest e-cigarettes on the market comes from one of the original ecig mod makers.  The SD Keychain by Trog is an interesting hybrid of a stealth e-cigarette mod and standard electronic cigarette.  The most notable thing about the SD Keychain is its diminutive size (and price).  In the SD Keychain review that follows we’ll see if good things really do come in small packages.

What’s in the Box

Like they sell them next to the Altoids

Or in this case, packaging.  The SD Keychain comes in one of those blister pack type containers complete with the little punch hole to hang it on a retail display.  The instructions are printed right on the back of the packaging.  This is a fairly humble kit, so there’s not a lot of things to unpack:

1 SD Keychain battery
2 pre-filled cartomizers (generic tobacco flavors)
1 keychain lanyard (attached to the SD)
1 510 USB charger

E-cigarette Design

The single biggest thing about the SD Keychain is its size.  The Keychain is positively tiny.  Lengthwise, it’s considerably shorter than a traditional e-cigarette and a bit thinner than an eGo electronic cigarette.

Popular size e-cigarettes

Matched with a standard cartomizer or atomizer, the e-cigarette easily fits into my fist for grabbing a vape on the sly.  Oddly enough, it also pairs pretty well with a cartomizer tank — though I would recommend a single coil cartomizer over a dual coil in this case.

The overall design of the SD Screwdriver is simplicity itself.  The device is fairly hefty for its size which indicates it’s likely constructed of stainless steel.  The top of the device sports a 510 connector, while the bottom of the tube has the SD log screened on it.

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There is a small lanyard attached to the tube with a key ring attached to the other end.  Yep, the SD Keychain is actually a keychain.  You can remove the keychain portion if you don’t intend it to hold your keys alongside your lucky rabbit’s foot and 32 shopper loyalty cards.

Other than the lanyard, the tube is totally smooth.  There are no lights and no buttons.  The SD Keychain is an automatic device all the way.  While I’m still not the biggest fan of auto batteries, it seems to work for this device.

Using the SD Keychain

510 connection

The keychain’s size and sturdy construction make this device one of the most pocketable around. Despite its size, the SD Keychain has a 300mAh battery on-board.  This certainly won’t give you that “all day vape.” It does however work as a backup e-cigarette or in times where discretion is warranted.

The lack of lights and easy palming of the SD keychain makes it a perfect stealth mod.  It also does perform well as a traditional device.  Unfortunately, because of the automatic battery, I wasn’t able to get any voltage readings, but I suspect it outputs at least 3.7v.

When not in a stealthy mood, I’ve actually taken to bolting on a full-size 5ml cartomizer tank on the SD keychain.  I have to admit it looks a little strange since the tank is much bigger than the e-cigarette its perched upon.  I’ve ordered a smaller 3.5ml tank from MadVapes to help balance out the looks.

Inside that tank I’m using a SmokTech 1.7Ω single coil cartomizer (I think dual coils require more oomph).  Vapor production is excellent with this combination.  Battery life suffers a little, but I was still able to coax over 2 hours of run time out of the device with this configuration.  Don’t try that with a regular 510 e-cigarette!

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A little top heavy

I haven’t really run into any funky issues with this device, save for one.  This isn’t really even native to the SD Keychain, but a potential issue with most automatic e-cigarette batteries.  One of my tanks leaked while the keychain was sitting upright dumping e-liquid straight down the hole in the atomizer connector on the keychain.

Almost immediately, the SD Keychain started activating on its own.  Fortunately, I was able to quickly remove the atomizer and get the excess juice out of the device.  After a some airing out time (and some crying), the little e-cig that could started working like a champ again.  I, however, would advise you do your best to keep e-liquid from dripping into the 510 connector.


e-cigarette reviews Sd Keychain review


Too Long; Didn’t Read

The SD Keychain is a tiny automatic e-cigarette designed by one of the original mod makers.  The device feels solid and performs fantastically despite not being a manual device.  While 300mAh won’t last you all day, it’s a lot better than most standard e-cigarettes.  Its performance and incredibly compact size make it a great candidate for a stealth, backup or ultra-portable device without damaging the wallet.  You can grab yours from (International readers, see the details section)

Do you have an SD Keychain (or just an opinion?) Let’s hear it in the comments section below!


  • Inexpensive
  • Solidly built
  • Tiny
  • Great performance


  • Automatic batteries more failure prone
  • Not an all-day device
  • Not the greatest key ring in the world


Product Name: SD Keyring by Trog
Buy it at: ElectronicStix
International customers can buy one from Liberty Flights (save 10% with code SteveVape)
Price: 19.95
Threading: 510
Battery: Sealed, 300mAh

Steve K

Hello and welcome to Steve K


  • Great for emergency backup. Mine came with uncharged battery and camel cartomisers. Which i found to be quite good. Kind of sweet. I removed the string and used keyring thru hole. Otherwise it hangs to low and hits my knee when driving. Works great. Use single coil cartos if you want it to last. Remember it is a novelty back-up. Which you will be glad you had. if you run out and forgot to bring a spare.

    • Truth be told, I only kept the cartos for the pictures. After that, I tossed them into my big basket of mystery pre-filled cartomizers. I also removed the lanyard, which is a lot harder to take off than you'd think. Still waiting on my 3.5ml tank to go with it. Then I'll have a little carto tank stealth setup.

  • There are several on the Dual Coil 510 Tank Cartomizer! thread looking for other cartos to fit that tank and one in particular looking for a single coil that's close the the right length. is the SmokTech 1.7Ω single coil cartomizer the right length or close to it?


    • The Smoktech 1.7s are perfect. In fact, Crystal Clear Vaping actually has the pre-punched 1.7s with the flange. Unfortunately, CCV is going through some growing pains right now, so I'm not sure if that's the best place to order from, or if it's wiser to wait for their issues to even out.

  • cool review Steve! what's the best cartos(performance wise) to use on the SD? the 1.7 smoktechs or the 2.0 boges? TIA for your reply

    • Thank you!

      I'd say you can't go wrong with either one. Both are good cartos, so it's more of a personal preference. The Boges are shorter (assuming you don't get XLs, they do exist) so that might keep things smaller. I like the Smoktechs myself, mostly because I use tanks.

      • Thanks for the tip Steve! think I'm gonna go with the 2.0 Boges cuz they're shorter/more steathy & try 1 of those MV 3.5ml DCTs(cut down to fit the boges, of course) awesome Steve, looking forward to your future reviews :-)

  • I have bought dual coil cartos for mine should i refrain from using them could i damage the battery? can someone help im new to all this.

    • I don't think that dual coils would damage anything. I'm just not sure what kind of performance you would get out of them. Although there are many who disagree with me and prefer dual coils at lower voltages.

  • Thanks steve for the quick reply it is helpful im just hoping the dual coils dont drain the battery too quick because it isnt that great as it is.I may be considering buying another device just for when im at home any thing you could recommend something with a long battery life cheers.

    • Well, there's a lot of choices for devices with big batteries. Or, if it's for home use mostly, you could just get an eGo pass-through there's even a variable voltage one if you want to get fancy. Those let you vape while it's attached to the computer's USB port. Here's a review on the variable voltage model.

      Note that it's been updated because the original model didn't support vaping while it was plugged in (dumb, I know) but the new versions do.

  • Thanks for the tips steve and the link ill have a read.

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