Nitecore SRT7 Revenger (1x18650, XM-L2 T6, 960lm) review

Moderators: This thread is intended for the Flashlight Reviews forum.

I've been carrying my Fenix LD20 day-in, day-out for close to three years, and it still works like a charm. More recently, though, I've been thinking about upgrading to 18650 to get better performance and runtime. After a bit of thought, I ultimately purchased a Nitecore SRT7 Revenger from B&H, along with a 3400 mAh Nitecore protected 18650 battery (model NL189) and Nitecore Intellicharger i2. I don't intend to cover the more technical aspects of the flashlight such as measured brightness or runtime (for that, there's selfbuilt's review), but here's a review that focuses on the more tangible aspects of the light.

Design and build

• The SRT7 is constructed from type-III hard-anodized aircraft-grade aluminum. Build quality is excellent, as good as or better than the LD20. All threads, as well as the Smart Selector Ring, are well lubricated out of the box.
• A single 18650 battery, two CR123A cells, or two 16340 (RCR123A) cells can be used with this flashlight. The positive contact uses a Nitecore proprietary design with a flat surface and recessed positive contact mounted on a spring. This design provides added shock and vibration resistance as well as protection against reverse battery insertion, but only button-top batteries will reliably make contact with the connector. The Nitecore 3400 mAh battery is slightly tight in the battery tube, but it does smoothly slide in and out of the light.
• Physically, the SRT7 is quite large and heavy for a single-18650 flashlight. Much of this bulk is in the large head, which contains an unusually large reflector which accommodates three RGB emitters in addition to the main LED and control ring (more on this below). It's about as large as I would carry for EDC, but some people may find it too bulky for this purpose. See image below.
• The SRT7 is rated as fully waterproof (IPX8) and submersible to 2 meters. As expected, no ingress or malfunction resulted after brief immersion in a small bowl of water. (A flashlight which is specified as waterproof but fails this test should be considered defective.)
• The clip is supplied detached from the flashlight and can be positioned for either bezel-up and bezel-down carry. Attachment and removal are both easy, and the clip fits snugly on the light.
• The holster is made of heavy-duty nylon, with a thin layer of neoprene on the flap and inside back. Quality is excellent, considerably better than the one which came with the LD20, and it should hold up to many years of daily use.

Pentax K-5 with DA 18-135mm @ 100mm. Av, 1/160s f/13 ISO 400. Bounce flash from ceiling. Processed from RAW in RawTherapee.

Nitecore SRT7 Revenger: Size Comparison by DragonLord878, on Flickr

User interface

• The SRT7 provides continuously-variable brightness operation as well as standby, tactical strobe, beacon, red/green/blue color, and police warning modes. All of these modes are accessed through a magnetic (Hall-effect sensor-based) Smart Selector Ring (SSR) mounted on the head of the light.
• A large portion of the rotating range of the SSR is dedicated to the continuously variable brightness range, with about 105 degrees rotation from minimum brightness to maximum. The ring clicks at specific positions for the standby, maximum brightness, and each of the other modes. Full rotation range is about 315 degrees, with hard stops at each end; the ring does not rotate freely through a full 360 degrees. Physically, the SSR has moderate damping with a slightly rough feel, and the detents are reasonably firm.
• Despite the seeming complexity of the light, operation is simple and intuitive because all modes are accessed through the SSR. The tactical forward-clicky tailcap switch is long enough for comfortable momentary-on operation, while still allowing the flashlight to tailstand. The tailcap has anodized threads, allowing the light to be locked out against accidental operation.
• The continuously-variable brightness control is perceptually linear so adjustments are smooth and natural. It's not completely stepless as the brightness changes in steps when the ring is turned very slowly (most noticeable in a dark environment at low brightness settings), but the steps are fine enough that it's essentially indistinguishable from completely smooth adjustment during normal use.
• A small red indicator LED is present on the head of the light. The indicator blinks every two seconds when in standby, and during operation when the battery is below 50%. Low battery is indicated by rapid, continuous flashing of this LED. It's a nice touch, a simple and efficient way to indicate battery status.

Performance and operation

• The SRT7 uses a T6-bin Cree XLamp XM-L2 LED and is rated to a maximum of 960 lumens. Although the manufacturer-claimed minimum brightness is 0.1 lumens, the light does not appear to run that low; my sample goes down to about 1 lumen when the battery is fully charged. All output levels appear to be current-controlled as PWM was not detected during testing.
• Both maximum and (to a lesser degree) minimum brightness are dependent on the state of charge of the battery. During my first use of the light, when the battery was 40% charged, and the SRT7 didn't appear to be outputting anywhere near 960 lumens. However, once I fully charged the battery, it was much brighter than my LD20. At the same time, the lowest setting became slightly brighter as well. I suspect an IMR battery (designed for high continuous discharge rates of 20+ amps) will maintain full brightness for longer.
• The beam pattern is very similar to that of my LD20, but with a slightly broader corona providing a smoother transition from hotspot to spill. However, the beam quality is not as good, with artifacts visible in the corona due to the cutouts for the RGB LEDs. I personally don't find it to be a problem in real-world usage.
• My sample of the SRT7 has a purplish tint, in stark contrast to the greenish output of my LD20. To my eyes, the output of the SRT7 is a bit more natural than what I get from the LD20.
• When turning on the flashlight at brightness settings less than maximum, and when quickly adjusting brightness, there is a smooth transition to the set brightness level. This "soft-start" behavior avoids the startling effect of sudden brightness changes and gives the light a bit of a sense of grace during operation. This ramp-up is disabled when the flashlight is set to max for use in tactical applications.
• A slight delay on the order of 0.15 seconds is observed when turning on the flashlight using the tailcap switch. This latency, which is probably caused by the driver electronics, is generally acceptable but may interfere with tactical use.
• At brightness levels similar to the LD20's maximum, the SRT7 runs very cool, only feeling slightly warm after several minutes of operation. The LD20 can get very hot if running at max for more than a few minutes. While the same can be said of the SRT7 when set to max, the higher efficiency of the XM-L2 emitter compared to that of the much older XP-G is evident in this reduced heat output. (The Cree XLamp XP-G dates back to 2009!)
• Although the RGB color modes don't provide very even lighting, they're nice to have and I can imagine useful applications for these modes.

Overall, this is an excellent multipurpose tactical flashlight, and I'm glad I decided to step up to 18650 lithium-ion. This is a cutting-edge flashlight, the continuously-variable brightness and multitude of modes making the SRT7 a versatile light for a vast array of use cases. It's safe to say that the Nitecore SRT7 Revenger has dethroned the Fenix LD20 as my primary EDC light after nearly three years of continuous service. (I'll continue to carry my LD20 in my handbag as a backup light, but the SRT7 is what goes on my belt.)

Questions, comments, or concerns?

--DragonLord

Re: Nitecore SRT7 Revenger review

Updated to add waterproofing and battery info.

There seems to be an issue with Flickr right now, as the image isn't loading. Closer examination reveals that it's returning HTTP 500, so one of their servers (specifically farm4.staticflickr.com) is probably having some trouble.

Edit: The problem has been resolved.

--DragonLord

Re: Nitecore SRT7 Revenger review

Thank you for the review DragonLord. The SRT7 is my go to dog walking light. Very easy to use, no fumbling for hard to find switches or head twisting. Just a little light to see what the dogs sniffing and alot of light for the cars, or strobe if they're being really dense.

Re: Nitecore SRT7 Revenger review

Nice compact review TY. I've owned my SRT7 since April and like it very much. While your FL has a purplish tint which I've also heard about from others mine has a slight greenish tint. Most of the time I don't even notice it though.

My wife and I like to table stand it at night even though it is not very stable. I tried carrying it in my pocket as an EDC early on but it popped out a few time when I stood up. This resulted in a slight deformation on one of the lanyard holes and it no longer tail stands on its own.

I've found that the low voltage indicator (red LED) starts blinking about once every five seconds in turbo mode when the cell is right around 3.62 V. I try to recharge the cell when it is greater than 3.80 V which to my understanding is at about 50%.

Also there are video's on the net and a CPF member (phambob) that have used it as a dive light. Here's the thread that discusses it.

It sounds like you'll enjoy this light as much as my wife and I have.

Re: Nitecore SRT7 Revenger review

this is a nice review. how does it feel in the hand after continuous use? i remember looking at a review which also mentioned about the head heavy balance. i can imagine after long use, it might feel heavier than it really is. i guess you could just shift your hand up.

i really am looking for a new toy for my birthday and i'm struggling between this, the nitecore cu6 and klarus rs20. i'm always a fan of a selector ring for output. hard to choose.

the advantage of the srt7 would be the long throw and the multi color led. do you think the multicolor led is useful in the long run?

Re: Nitecore SRT7 Revenger review

f22shift said:

this is a nice review. how does it feel in the hand after continuous use? i remember looking at a review which also mentioned about the head heavy balance. i can imagine after long use, it might feel heavier than it really is. i guess you could just shift your hand up.

i really am looking for a new toy for my birthday and i'm struggling between this, the nitecore cu6 and klarus rs20. i'm always a fan of a selector ring for output. hard to choose.

the advantage of the srt7 would be the long throw and the multi color led. do you think the multicolor led is useful in the long run?

Click to expand...

The light feels a bit front-heavy during use but isn't uncomfortable to hold continuously. From what I can tell, the head is constructed of a single large piece of milled aluminum, so I'd say it's designed to be rock-solid above all else. If run on Turbo continuously, the light will get very warm after a few minutes of use, but it does not become uncomfortably hot.

I'm pretty sure you'll find uses for the RGB LEDs, but the UV emitter on the Chameleon CU6 might be more useful if you're going to authenticate currency, etc. Keep in mind that the Chameleon series has its own set of RGB emitters alongside primary white and single-color emitters. Of course, it's up to you to decide which model fits your needs better.

--DragonLord

Re: Nitecore SRT7 Revenger review

f22shift said:

this is a nice review. how does it feel in the hand after continuous use? i remember looking at a review which also mentioned about the head heavy balance. i can imagine after long use, it might feel heavier than it really is. i guess you could just shift your hand up.

i really am looking for a new toy for my birthday and i'm struggling between this, the nitecore cu6 and klarus rs20. i'm always a fan of a selector ring for output. hard to choose.

the advantage of the srt7 would be the long throw and the multi color led. do you think the multicolor led is useful in the long run?

Click to expand...

I agree that it is a little front heavy but not too uncomfortable. I found little use for the RGB but since the SRT6 & SRT7 costs about the same and the specs are a little better on the SRT7 then I went with it.

Re: Nitecore SRT7 Revenger review

I know this is an old thread but the SRT6 and SRT7 have always been a sore spot for me due to their actual output versus what Nitecore falsely claims is a 960 and 930 lumen light. As per Selfbuilts review, the 960 lumen number is Nitecore marketing BS fantasy. With an 18650 the SRT7 puts 780 lumens out the front nearly a full 200 lumens less than what Nitecore trumpets in their advertising. 2x sources do indeed get the output going more. 2x CR123 cells equals 870 lumens OTF. That is quite a jump! Unfortunately 3v CR123 cells will have the red low voltage indicator on the heads of both lights going crazy almost instantly even if the CR123's are fresh. RCR123's at 3.7v will have the SRT7 putting out 10 less lumens, 860, OTF. Still quite a jump in the right direction but still falling 100 lumens short of claimed output.

Ive had my SRT7 since it was first released a couple of years ago. Used the hell out of it for the first year, broke the chintzy plastic "tactical ring" in half. Through knowledge gained on this forum I now run RCR123's in both my 6 and my 7. The difference is quite noticeable although both still fall short of claimed output by at least 100 lumens. I remember when a buddy of mine showed me his 2014 TK22 I was slackjawed. Not only did it smoke my 6 and 7 in output it had a metal tactical ring and a better beam. Bought one for myself and it was the turning point when my SRT6 and 7 had their batteries pulled and put on a shelf. Then came the Olight M22, Eagletac G25C2 MkII etc. All of which flat smoke the megahyped SRT's and cost less to.

The only good thing about the SRT6 and 7 is the smart ring control. Even after a year of heavy use my SRT7's control ring only got smoother. I wish Vinh would modify Nitecores (he wont modify most Nitecores for some reason) Id have him pump mine up to where they at least meet advertised specs....end rant

Re: Nitecore SRT7 Revenger review

The 780 lm measured output is with an older 2200 mAh battery, and those older batteries probably had higher internal resistance and therefore more voltage drop than newer high-capacity batteries. I'm getting closer to 850-900 lm on mine using a Nitecore NL189, a 3400 mAh protected Panasonic NCR18650B.

Voltage under load is what truly matters here. Newer, more powerful batteries will inevitably provide better performance than older cells. The CR123A cells probably sag a lot under heavy load as well because of their lower capacity, so the higher voltage only goes so far in bringing up brightness.

It's still not 960 lm, but your choice of battery counts. IMR batteries will probably be the best performers in these sorts of lights, but their high discharge capability comes at the cost of shorter overall runtime.

—DragonLord