MecArmy SGN7 Keychain Flashlight Review

The MecArmy SGN7 keychain flashlight uses two switches for controlling the Cree XP-G2 emitter. The aluminum body has red anodizing. Read on!

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Official Specs and Features

Here’s a link to the MecArmy SGN7 Keychain Flashlight product page.

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.

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Short Review

While this light is just a big, bulky one, 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

The Big Table

MecArmy SGN7
Emitter:	Cree XP-G2 (S4)
Price in USD at publication time:	$49.19
Cell:	Internal
Turbo Runtime
LVP?	Yes
Switch Type:	E-Switch
Quiescent Current (A):	?
On-Board Charging?	Yes
Chargetime
Power off Charge Port with no Cell?	?
Claimed Lumens (lm)	550
Claimed Throw (m)	120
Candela (Calculated) in cd (at 30s)	221lux @ 3.887m = 3339cd
Throw (Calculated) (m)	115.6 (96.3% of claim)^
All my MecArmy reviews!

^ Measurement disclaimer: Testing flashlights is my hobby. I use hobbyist-level equipment for testing, including some I made myself. Try not to get buried in the details of manufacturer specifications versus measurements recorded here; A certain amount of difference (say, 10 or 15%) is perfectly reasonable.

What’s Included

• MecArmy SGN7
• Lanyard
• Charge cable
• Manual

Package and Manual

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

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

Build Quality and Disassembly

This is a very square, 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.

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 its 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.

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).

Also included is a lanyard, which could attach to 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).

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.

Charging

Also built into this light (of course, since it’s an internal cell) is onboard 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.

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

Powerbank

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.

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.

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.

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 user interface 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 a keychain-light-type beam profile.

Beamshots

These beamshots always have the following settings: f8, ISO100, 0.3s shutter, and manual 5000K exposure. These photos are taken at floor level, and the beam hits the ceiling around 9 feet away.

Tint vs BLF-348 (KillzoneFlashlights.com 219b version) (affiliate link)

I keep the test flashlight on the left and the BLF-348 reference flashlight on the right.

Random Comparisons and Competitive Options

Here’s a relevantly filtered page on parametrek.com. A light with an internal cell, a 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

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

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Notes

• This light was provided by GearBest for review. I was not paid to write this review.
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