MecArmy SGN7 Keychain Flashlight Review

Preface

Seems that I’ve been on a keychain light kick lately, and here’s another one!  Well, in some sense, anyway.  This is more of a rectangular light with unusual features….   Also my first MecArmy light in basically forever (the other being the PT16, which I really liked.)  Read on for more info and thoughts about this MecArmy SGN7!


Official Specs and Features

Versions

There are a number of body colors available for the SGN7:  Black, Silver, Pink (“Rose”), Blue, Tan (“Gold”), and Red (seen here).  There are no other options available for the light.

Price

Looks like retail is around $60, but the light is $49.19 on GearBest right now.


Short Review

While this light is just a big bulky, it does have an unusual feature set, and could be useful in a pinch.  The alarm (siren) is…. unexpected, and also very loud.  The powerbank option is, again, unexpected, and does work as intended.

Long Review

What’s Included

  • MecArmy SGN7
  • Lanyard
  • Charge cable
  • Manual

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Package and Manual

The SGN7 ships in a display-ready cardboard box, with a fair amount of printing.  There’s  large GearBest inventory sticker on the back, which covers nearly half the printing.

The manual is completely in English, and printed both sides of this small slip of paper.  It’s a fairly comprehensive manual.

Build Quality and Disassembly

This is a very squared, fairly dense little light.  I’m not sure it’s referred to in the product literature this way, but I suppose it’s a “unibody” construction – the top and sides are one piece, with the bottom being screwed in with two Torx screws.

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Size

Officially 59mm long and 23mm wide.  I actually measured it at 75mm long and 34.5mm wide – quite a discrepancy.  Maybe someone at MecArmy forgot to zero their caliper that day…  The bezel is 20mm at it’s thickest, and the rest of the body is around 14mm.  It’s quite a chunky little ‘keychain’ light.

To be fair to MecArmy, later text does reveal they know how to measure, and their numbers match mine.

Compared to other keychain lights, one can see how much of a keychain light this one isn’t.

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Retention

A pocket clip comes installed on the SGN7, and may be removed.  Two Hex screws hold it on.  As chunky as this light is, I have to say that it rides quite comfortably in my main pocket.  It also slips into the pocket quite easily (owing mainly to the large flat area of the body that the clip presses against.)

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Also included is a lanyard, which could attach on the built-in loop at the end of the light, or also attach on the pocket clip in a couple of places.

This loop on the end could also be used for attaching the light to a split ring.  A split ring is not included.

Power

The SGN7 has an internal cell, which isn’t replaceable.  MecArmy says that the SGN7 has a “650mAh” internal lithium battery.  I tested the light on Turbo, and below you may see the runtime.  The claim is 44m on turbo, but either way I slide the runtime I can’t confirm that.  Turbo steps down quite quickly, all the way to 40% output (at around 2 minutes).  After that, there’s a steady decline until about 80 minutes, where the light shuts off (Low Voltage Protection).

Runtime.png

I’m not sure how big a problem this is, really.  I wouldn’t expect a keychain light to be carried as a “I need 550 lumens for an hour” light – it’s going to be a short-burst light.  For that, this runtime isn’t too bad.  Note that it’s very difficult to track temperature on an oddly shaped light like this (at least with my setup), so don’t regard that temp too much.

Also built in to this light, (of course, since it’s an internal cell), is on-board charging via micro-USB.  The port is snug and well fit, and the little rubber cover actually fits inside the port and covers it as well.  I struggled and struggled with this cover… I finally had to get something to pick at it to get the thing opened.  There is a little flap; I just couldn’t manage without a tool.

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MecArmy claims a full charge in 1 hour.  You can see below that that’s approximately true.  The light charges at around 1A in the CC phase.  I measured the cell at only around 600mAh.

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The other unusual feature of this light is that there’s a full-sized USB port so that this 600-650mAh cell may be used as a Powerbank.  (!!!)  MecArmy smartly makes realistic claims, though, and says that the SGN7 will give the normal/current phones 11 or 12% charge.  That’s not much, but it might be just what one needs for an emergency call.  And it does actually work.

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I did a quick test on the USB-out and as you can see, the SGN7 can output up to 1A while staying at 4V (which is below spec).  An iPhone or Android phone should only draw 0.5A from this device, and the SGN7 provides that in-spec.

Powerbank.png

User Interface and Operation

The SGN7 has two switches, both with a silicone cover.  The “top” has a power sign, and is used for the light.  The bottom, a triangle shaped boot, has an “alarm” sign, and is used for the alarm siren.   Both these switches are nicely clicky, and easy to find.

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What I don’t like is how close they are.  What I do like is that the siren doesn’t activate on a single click – it takes some intent to activate it.

Here’s a UI table!

State Action Result
Off Click (Power Switch) Low
Off Hold (PS) Momentary Turbo
Off Double Click (PS) Turbo
Off Triple Click (PS) Strobe
Strobe Long Click (>1s) (PS) SOS
On Click (PS) Off
On Hold (PS) Mode Cycle (LMHT)
Off Hold (>1.5s) (Siren Switch) Siren
On Click (SS) Off

Modes

Mode Mode Claimed Output (lm) Claimed Runtime Mode Measured Lux
Turbo 550 44m 9950
 High 120 2.27h 2420
 Med 20 15.67h 409
 Low 1.55 117h 36
 Strobe 410

LED and Beam

The SGN7 has a Cree XP-G2 S4, and a very smooth reflector.  It’s shallow and broad, yet provides a fairly intense spot with little spill.  Not really what one usually expects (or wants) from a keychain light.  However, it’s a nice beam shape, if one isn’t expecting keychain-light-type beam profile.

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Tint vs BLF-348

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Beamshots, Runtime, and Lux Measurements

MecArmy SGN7
Emitter Cree XP-G2
Emitter Notes S4
Cell Internal
Glamour Shots Beamshots [0.3″, f/8, ISO 100, 5000k]
Runtime Chargetime
LVP? Yes
Claimed Lumens (lm) 550
Lux (Measured) 221 lux @ 3.887 m
Candela (Calculated) in cd 3339.0
Throw (Calculated) (m) 115.6
Throw (Claimed) (m) 120

 

Random Comparisons and Competitive Options….

A light with an internal cell, powerbank feature, and an alarm siren.  There’s really nothing else like that (unless there is and I just missed it, let me know in the comments).  If those are features you need, then this is the perfect light.

Conclusion

What I like

  • Unusual and very full set of features
  • All the intended features work as planned
  • On-board charging is very quick
  • The siren is… loud… [ringing in ears]

What I don’t like

  • Alarm siren switch is too close to the main switch.
  • The light is bulky, and doesn’t handle well

Up Next

Hoping to wrap on the Olight X7R by Friday, and who knows, maybe something else this week too!  Next week I have another host of lights!

Notes

  • This light was provided by GearBest for review. I was not paid to write this review.
  • This content originally appeared at zeroair.wordpress.com.  Please visit there for the best experience!
  • Whether or not I have a coupon for this light, I do have a bunch of coupons!!  Have a look at my spreadsheet for those coupons. It’s possible to subscribe and get notifications when the sheet is edited!!

Author: zeroair

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