# JetBeam SRA40 (XM-L2, 4xAA, In-Light Charger) Review: RUNTIMES, BEAMSHOTS, VIDEO+



## selfbuilt (Nov 25, 2013)

*Warning: pic heavy, as usual. *















The SRA40 is the latest 4xAA light from JetBeam, featuring a cool white XM-L2 emitter. It also features the novel twist of in-light charging for four NiMH AAs. 

I've reviewed a number of 3x and 4x XM-L/XM-L2 lights recently. Let's see how it does against the recent competition in this space. :wave:

*Manufacturer Reported Specifications:* 
(note: as always, these are simply what the manufacturer provides – scroll down to see my actual testing results).


LED: CREE XM-L2
Runs on: 4x AA (NiMh/Alkaline) (Batteries not included)
Output mode/Runtime: High: 960 lumens / 2hrs, Mid: 240 lumens / 5hrs, Low: 20 lumens / 45hrs
Peak Beam Intensity: 38,000cd
Easy access to 3 levels of outputs with innovative dual switches
'Precision Digital Technology' achieves a max runtime of 45 hours
'Crystal Coating Technology' provides extreme reflector performance of 390m beam distance
Ergonomic design with four-side milling and traditional knurling
Intelligent charging function
Low power LED indicator shows the condition of power
Toughened ultra-clear mineral glass with double-sided anti-reflective coating ensures the highest optical efficiency and light transmittance
Waterproof to IPX-8 standards (2 meters under water)
Premium type III hard-anodized anti-abrasive finish
Tail stand capability
Impact resistance: 1.5 meters
Different batteries compatible, 4x AA Rechargeable batteries recommended or 4x AA
Alkaline batteries usable
Includes AC adapter
Dimensions: Length: 4.9" (125mm), Head Diameter: 1.5" (38.3mm), Body Diameter: 1.4" (36.05mm)
MSRP: ~$100






The SRA40 comes in presentation clamshell plastic packaging. An overview of the light and its specs are printed on the packaging. Inside, you will find the light, AC power charging cable, basic wrist strap, extra o-ring, manual, product insert and warranty card. 













From left to right: Duracell NiMH; JetBeam SRA40; Nitecore EA4; Sunwayman D40A; Eagletac GX25A3; Lumintop SD10; Olight S35.

All dimensions directly measured, and given with no batteries installed (unless indicated):

*JetBeam SRA40 4xAA*: Weight 236.0g, Length: 126.1mm, Width (bezel): 48.5mm
*JetBeam PA40 4xAA*: Weight: 184.0g, Length: 183mm, Width: 40.8mm (bezel), 42.1mm (max width)
*Lumintop SD10*: Weight: 117.6g, Length: 120.3mm, Width (bezel): 40.1mm
*Sunwayman D40A 4xAA*: Weight: 167.9g, Length: 120.4mm, Weight (bezel): 40.0mm
*Eagletac GX25A3 3xAA*: Weight: 151.4g, Length: 109.2mm, Weight (bezel): 38.6mm
*Nitecore EA4 4xAA*: Weight: 161.6g , Length: 117.9mm, Width (bezel): 40.2mm
*Olight S35 3xAA*: Weight 177.3g, Length: 127.7mm, Width (bezel): 38.7mm

The SRA40 is a more substantial light than other recent offerings in the 4xAA space. The in-light charging feature is likely to account for some of the extra length, but you will also note the reflector is wider and deeper than other recent lights.






























The overall build of the SRA40 is top-notch – it is a very solid feeling light. :thumbsup: Hand feel is good, and there are a reasonable number of grip elements along the body. Knurling could be more aggressive, though. 

Anodizing is a dark gray neutral finish, very attractive in my view. Anodizing was flawless on my sample, and appears to be quite thick – they have done a nice job here.  Labels are clear against the gray background. 

Screw threading is standard triangular cut, but seems of good quality. Threads are anodized, but it will take quite a few turns to physically lock out the tailcap (due to the tension that is carried by the battery springs). Physical lock out is still feasible though, and there are still enough threads to prevent the tailcap from falling off at that point.

The SRA40 can tailstand easily, thanks to the raise cut-outs. These make suitable lanyard attachment points as well. There is a standard tripod screw attachment in the base as well.

Battery handle is quite compact, but easily houses 4xAA (alkaline, NiMH or L91). The battery compartments are molded right into the aluminum. Despite how the handle looks, the batteries don't seem to be all in series – the light instead appears to be 2s2p (i.e., two parallel channels of two cells in series). I noticed this when doing current draws, as I was able to activate the light by using just two cells in ajoining well pairs. Note however that the light will not run on just two cells with the tailcap in place. Presumably, the tailcap contact board design requires both pairs of contacts to be closed (i.e., fully connected). 

Although the light can roll, the cut-outs in the head do serve as fairly effective anti-roll features (i.e., it is less likely to roll than competing recent 3x/4x lights).

There is a dual-switch interface in the head to control the light. These are both electronic switches, with standard feel for this class. There are two small blue LED indicators beneath the mode changing button (used as a battery power indicator and charging indicator). See User Interface below for more information. 


















The SRA40 comes with a dedicated AC charger (with appropriate connector for the world region you order it for). The charger indicates a 350mA charging current, which given the 2s2p arrangement, would suggest over 11 hours to fully charge a depleted set 2000mAh NiMH batteries. 

In my testing, it takes somewhere between 10 and 11 hours for the two indicators to stop alternating (i.e., the sign than charging is complete). My Maha MH-C9000 indicates the batteries are fully charged at this point. However, on a subsequent run, I stopped the charger after ~8.5 hours, and the batteries were already nearly fully charged according to my Maha.










The SRA40 reflector is smooth, and fairly large and deep (i.e., slightly larger than my other recent 4xAA lights). This should translate into very good throw for the size. The XM-L2 emitter was well centered on my sample

*User Interface*

Main on/off operation is controlled by the lower Power switch – press and release (i.e., click) to turn the light on at the previously memorized constant output level. Turn the light off by clicking the Power switch again. 

While on, click the upper Mode switch repeatedly to cycle between the three main output levels in the following repeating sequence: Hi > Med > Lo. I personally would have preferred the other way round. The light remembers your last choice and returns you to it after pressing the power switch off/on (after after a battery change).

Press and hold the Power switch to activate in tactical Strobe. This works if the light is on or off.

Press and hold the Mode switch to activate SOS. This only works if the light is on. If the light is off, pressing the Mode switch give you a battery charge readout (two blue LEDs means fully charged, one LED means <=50% charged, and a flashing indicator means the cells are discharged). The same readout occurs when you first activate the light in any mode.

I don't see any indication of an electronic lock-out mode in the JetBeam documentation.

Note there is one quirk to the light – it comes on in whatever the last saved mode was when replacing the batteries. You have to turn the light off at the Power switch once you get the tailcap fully re-engaged. :shrug:

*Video*: 

For more information on the light, including the build and user interface, please see my video overview:



Video was recorded in 720p, but YouTube typically defaults to 360p. Once the video is running, you can click on the configuration settings icon and select the higher 480p to 720p options. You can also run full-screen. 

As with all my videos, I recommend you have annotations turned on. I commonly update the commentary with additional information.

*PWM/Strobe*

There is no sign of PWM that I can see, at any output level – I believe the light is current-controlled.  

Strobe:





The main strobe is standard fast strobe, measured at 12 Hz on my SRA40.

SOS:





SRA40 has a standard SOS mode. 

*Standby Drain*

A standby current drain is inevitable on this light, due to the electronic switch in the head. I measured this current on 2xAA as 112uA initially, but it regularly dips down to ~80uA every second or so. Assuming this average ~100uA current remains constant when four cells are inserted (and the light is indeed 2s2p), that would mean over 4.5 years before 4x 2000mAh NiMH would be drained (and ignoring the actual faster self-discharge of NiMH, of couse). This is a perfectly reasonable standby current level. 

Physical lock-out requires a lot of turning of the tailcap – although you still have plenty of threads left to keep the tailcap attached. There does not seem to be an electronic lock-out, unfortunately.

*Beamshots:*

And now the white-wall beamshots.  All lights are on Sanyo Eneloop NiMH, at the maximum supported number for the given models (3x or 4x). Lights are about ~0.75 meter from a white wall (with the camera ~1.25 meters back from the wall). Automatic white balance on the camera, to minimize tint differences (i.e., my SX25A6 sample is a neutral white tint, but you won't be able to tell that below). 





























































The overall beam pattern is very similar to the Sunwayman D40A or Nitecore EA4 – except the SRA40 has a more focused hotspot (for greater throw). This is consistent with the larger reflector.

For outdoor beamshots, these are all done in the style of my earlier 100-yard round-up review. Please see that thread for a discussion of the topography (i.e. the road dips in the distance, to better show you the corona in the mid-ground). 










You can see the difference between in throw these lights – the SRA40 is the definite throw king in the 4xAA class at the moment. Scroll down to summary table for more details and direct measures.

*Testing Method:* 

All my output numbers are relative for my home-made light box setup, as described on my flashlightreviews.ca website. You can directly compare all my relative output values from different reviews - i.e. an output value of "10" in one graph is the same as "10" in another. All runtimes are done under a cooling fan, except for any extended run Lo/Min modes (i.e. >12 hours) which are done without cooling.

I have devised a method for converting my lightbox relative output values (ROV) to estimated Lumens. See my How to convert Selfbuilt's Lightbox values to Lumens thread for more info. 

*Throw/Output Summary Chart:*

My summary tables are reported in a manner consistent with the ANSI FL-1 standard for flashlight testing. Please see http://www.flashlightreviews.ca/FL1.htm for a discussion, and a description of all the terms used in these tables. Effective July 2012, I have updated all my Peak Intensity/Beam Distance measures with a NIST-certified Extech EA31 lightmeter (orange highlights).






As you can see, the SRA40 has excellent throw for this class – the highest I've seen for a 4xAA light so far. Max overall output is fairly similar to other recent 3x/4xAA lights. 

My output and throw measures seem very consistent with JetBeam specs, on max.






And again for Lo and Med.  Note that the initial step-down feature (after 3 mins) takes you to a lower Hi level. See runtimes below for more info.

*Output/Runtime Graphs:*
























The SRA40 actually shows a double-step-down on Hi. The first timed step-down occurs at 3 minutes, as indicated in the manual. But the light steps down again about 9 and a half minutes later. Final output after 12.5 mins is about ~480 estimated lumens on my scale. In any case, you can restore initial max output by cycling through levels with the Mode button, or by turning the light off/on.

As you can tell from above, JetBeam is using a good current-controlled circuit in the light. The SRA40's performance on Hi is excellent, and the Med mode is virtually identical to the Sunwayman D40A. 

On both Med and Hi, the light has a defined step-down to the Lo level, as the batteries near exhaustion. In my testing, there was still a lot of runtime left at this Lo level. :thumbsup:

*Potential Issues*

Light comes on automatically in the last memorized mode when re-installing the tailcap after changing the batteries (i.e., need to turn the switch off, once the tailcap is fully connected). 

Due to the electronic switches, there is a standby drain when not in use – but it is a reasonable ~100uA. Given the apparent 2s2p arrangement, that would suggest over 4 years before 2000mAh batteries would be fully drained (ignoring the significant self-discharge of NiMH, of course). While there is no apparent electronic lock-out mode to prevent accidental activation, you can physically lock-out the light by turning the tailcap a couple of full rotations. 

The built-in charger is not the most rapid at ~11 hours for a full charge, but I suppose it is a convenient option for those who want it (odd not have a USB option, though). However, as always, I recommend you individually charge your batteries regularly, to ensure each one is functioning well and is well-balanced to the others (i.e., repeatedly charging some cells in series is not a good idea). 

Light lacks a Moonlight mode, and mode sequence is Hi > Med > Lo.

Light features a double timed step-down from Hi, but you can easily restore full initial power by cycling through the modes or turning off/on.

*Preliminary Observations*

The SRA40 is the second offering by JetBeam in the 4xAA space (see my earlier PA40 review) – and the first in the popular category of cylindrical all-metal lights. The SRA40 distinguishes itself with the highest throw in my collection of 3x/4xAA lights at the moment (with comparable max output to the Eagletac GX25A3 or Sunwayman D40A). :thumbsup:

The SRA40 is probably the most "beefy" light of this group, with thicker walls and greater weight/length. I quite like the build and look of the light, but of course, that's a matter of personal preference (and relative hand size). :laughing:

User interface is fairly intuitive, with its two-button design. The two blue LEDs under the mode switch also provides some help, in terms of determining charge (or charging) status. That said, I would have liked to have seen the addition of a fourth "Moonlight" output mode, and a Lo > Hi sequence. :shrug:

Interestingly, the light is apparently run on a 2s2p arrangement (i.e., two parallel channels of two cells in series). But this doesn't mean you can run the light on just two cells - the tailcap apparently requires both pairs of contacts to be closed for the light to activate.

The in-light charging solution for NiMH is interesting, you don't see that very often. It worked fine in my testing, but I'm not a big fan of charging batteries in series. And the low charging current means it will take the better part of a day to fully charge depleted cells. 

Regulation and output/runtime performance at all levels tested were excellent, certainly on par with the recent competition. One unusual feature is the secondary step-down on Hi after 12.5 mins of accumulated runtime – but you can easily restore full max power by mode switching or turning off/on. 

The SRA40 is nice addition to the 3x/4xAA family of lights. More substantial in build than many of the other recent offerings, it will likely appeal to a different type of user (especially those looking to maximize throw). The SRA40 is a solid offering in this expanding class, with a fairly novel in-light charging option.

----

SRA40 was provided by JetBeam for review.


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## Ryp (Nov 25, 2013)

Thanks for the review!


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## bright star (Nov 25, 2013)

Reserved...


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## j3bnl (Nov 26, 2013)

Great review as always.
I have one of these on the way so good to see your review and I think I have made a good choice by the looks of things. 
How would you rate the build quality compared to the Sunwayman D40A?


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## Overclocker (Nov 26, 2013)

i'm curious about the charging algorithm... is it a delta-v termination?

since it's 2s2p then the 350ma current charges 4000mah. kinda low for reliable delta-v

then it doesn't have moonlight. no lockout. doesn't seem like a very good flashlight


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## selfbuilt (Nov 26, 2013)

To correct something I originally mentioned in the review: the light does not run with just two cells installed inside the light, with the tailcap in place.

When doing current draws, as I was able to activate the light by using just two cells in an ajoining well pair. The battery indicator lit up as fully charged, and the light seemed to function normally (although I didn't test all the modes, given that my DMM was on its uA/mA port). This led me to conclude the light was 2s2p.

However, I didn't actually try it with the tailcap in place. Testing it now, I see the light will not run on just two cells with the tailcap screwed down. The tailcap thus seems to need the other pair of contacts to be closed for the circuit to be made. I suppose it should be possible to short the tailcap contacts, but I'm not about to try that - the light is clearly not meant to run on just 2 cells (although this would seem to be technically possible, given my current draw tests).



j3bnl said:


> How would you rate the build quality compared to the Sunwayman D40A?


Direct comparisons are always hard to make. I can say that the SRA40 feels more "solid" (i.e., the body walls are made of thicker aluminum, and the light is a bit bigger with greater weight). But of course, the D40A has additional output modes (including moonlight).



Overclocker said:


> i'm curious about the charging algorithm... is it a delta-v termination?
> since it's 2s2p then the 350ma current charges 4000mah. kinda low for reliable delta-v


Agreed, I was surprised to see low current (especially considering the apparent 2s2p). Honestly have no idea what algorithm they are using. Also surprised to see they didn't just go for a USB-based option, instead of a dedicated transformer, given the relatively low current. :shrug:



> then it doesn't have moonlight. no lockout. doesn't seem like a very good flashlight


It does have a physical lock out - but you need to twist the tailcap somewhere between 2.5 and 3 full turns (on my sample) to reliably lock it out. The tailcap comes off around 4.5 full turns, so it is still stable in this configuration. But I agree, an eletronic lock-out would have been nice.


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## Essexman (Nov 30, 2013)

Re battery config: I don't think it can be 2s2p. From a view that would mean jetbeam have made a boost driver to run at high current (2 to 3 amps) from 2.4V input. Not easy, in fact I would say impossible.


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## selfbuilt (Nov 30, 2013)

Essexman said:


> Re battery config: I don't think it can be 2s2p. From a view that would mean jetbeam have made a boost driver to run at high current (2 to 3 amps) from 2.4V input. Not easy, in fact I would say impossible.


I would tend to agree - but I can bypass the tailcap and activate the light on just two cells. :thinking: Note that I did not try to measure the output while doing this, so it may be that all levels are greatly reduced. And you do need all four cells to activate with the tailcap ... but I'm at a loss as to how to explain the light activating and changing modes on just two cells.


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## AngryDaddyBird (Dec 27, 2013)

Awesome review as always! I was on the edge about this light because I have the ET GX25a3 & Nitecore Ea4. But after seeing the throw on the jetbeam i will get one. I really like the looks too!
is a Usb cable available fir the light or will it be available?


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## selfbuilt (Dec 27, 2013)

AngryDaddyBird said:


> is a Usb cable available fir the light or will it be available?


I don't know, you would have to check with JetBeam. I am actually a little surprised they didn't opt for a USB cable (with AC adapter), as that seems to be the more common route for most other makers. :shrug:


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## moldyoldy (Dec 29, 2013)

selfbuilt said:


> I don't know, you would have to check with JetBeam. I am actually a little surprised they didn't opt for a USB cable (with AC adapter), as that seems to be the more common route for most other makers. :shrug:



a fair question. However USB 2.0 delivers 5.0 +/- 0.25v. hence the lowest USB output voltage might be 4.75v. USB 3.0 voltage output minimum can be still lower. To charge a stack of 4x NiMH cells with an end voltage of ~1.4v/cell leaves no room for the circuitry overhead. Most silicon junctions operate at about 0.6 to 0.7 volts. Hence there is insufficient overhead voltage to control cell charging w/o a boost circuit - and that means more internal electronics and space. 

Alternatively Shottky junctions can operate down to ~0.2v, but they are expensive.

My copy of the JetBeam charger outputs 6.49volts - sufficient for internal charging circuitry w/o a boost circuit.

IOW, Jetbeam favored a simpler design with the charger outside the light.


Edit: based on my assortment of lights with internal charging, whether LiCO or NiMH cells, all of them are relatively slow compared with an external charger, presumably because of internal heat dissipation difficulties. Furthermore none of them provide the inherent cross-check of individual-channel charging. I generally do not use internal charging for any light.


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## CelticCross74 (Nov 30, 2014)

I know this is an old thread but Ive just got to add that I have had an SRA40 for a couple of months now and I have gotta say it is a BEAST!! The aluminum is soooo thick on this thing! I throws like a 4D M*g and is 8 times brighter than one lol! The beam profile out of this thing is astonishing! The most convincing 890 OTF lumens Ive ever seen thats for sure


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## selfbuilt (Nov 30, 2014)

CelticCross74 said:


> I know this is an old thread but Ive just got to add that I have had an SRA40 for a couple of months now and I have gotta say it is a BEAST!! The aluminum is soooo thick on this thing! I throws like a 4D M*g and is 8 times brighter than one lol! The beam profile out of this thing is astonishing! The most convincing 890 OTF lumens Ive ever seen thats for sure


Yes, it is distinctive for this 4xAA class - a lot "beefier", and with outstanding throw. Thanks for the bump - I've seen this light on a few black friday deal sites, so I imagine there is some interest in it out there. I will also include it in my soon to be released 4xAA round-up review (hopefully tomorrow, if I can finish everything).


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## CelticCross74 (Dec 1, 2014)

cant wait for your round up review! Ive got the EA41,D40A,GX25A3 and SRA40. The new 2015 1020 lumen EA41 shows up in the mail today. The about to be released Thrunite TN4A has been pre-ordered. Comparing these throwy little powerhouses is a blast!


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## Danielsan (Dec 3, 2014)

when i shake my SRA40 i can hear the power port rattling on the bottom, like the tiny contacts inside the power port, anybody else can hear this?


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## Grijon (Dec 3, 2014)

Excellent review; I'm truly grateful for such talent and knowledge shared so freely.


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## CelticCross74 (Dec 3, 2014)

Power port doesnt rattle on mine. Dont use it anyways as the charging system on the light doesnt charge the batteries all the way for some reason so I just use my MAHA charger. Seriously if youre hearing your power port rattle around contact Jetbeam about it


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## selfbuilt (Dec 3, 2014)

Danielsan said:


> when i shake my SRA40 i can hear the power port rattling on the bottom, like the tiny contacts inside the power port, anybody else can hear this?


By rattle on the bottom, do you mean the tailcap? This happens on mine too, but isn't very prominent when the tailcap is fully screwed down (with cells in place). It seems to be due to how the contact board in the tailcap is attached - there is more play than typical for this class, causing some rattle (minor on my sample).



Grijon said:


> Excellent review; I'm truly grateful for such talent and knowledge shared so freely.


My pleasure!


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## Danielsan (Dec 3, 2014)

selfbuilt said:


> By rattle on the bottom, do you mean the tailcap? This happens on mine too, but isn't very prominent when the tailcap is fully screwed down (with cells in place). It seems to be due to how the contact board in the tailcap is attached - there is more play than typical for this class, causing some rattle (minor on my sample).
> 
> 
> My pleasure!


no the round power port for the power plug. I guess this power plug has little contacts in it and you can hear them moving a litte on my SRA40. But the pwoer port works well, so it must be normal.



> Power port doesnt rattle on mine.



maybe because you never used the power port? just plug it in a few times and then shake the light hard near your ear


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## andrew2 (Dec 4, 2014)

Great review,this JetBeam flashlight looks really good ,It seems that Selfbuilt have done a lot of review here,how do you test the runtime,I am curious about it,want to test my torch in this way.:twothumbs


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## selfbuilt (Dec 4, 2014)

Danielsan said:


> no the round power port for the power plug. I guess this power plug has little contacts in it and you can hear them moving a litte on my SRA40. But the pwoer port works well, so it must be normal.


Ah, I see. Certainly no rattle there on my sample, and I did do several rounds of testing using the charging port. 



andrew2 said:


> Great review,this JetBeam flashlight looks really good ,It seems that Selfbuilt have done a lot of review here,how do you test the runtime,I am curious about it,want to test my torch in this way.:twothumbs


I explain my testing methodology in more detail on my Methods page on flashlightreviews.ca. Simply put, you will need some sort of integrating chamber to collect all the light, a data-logging light meter (with sensor appropriately shielded from direct light), and a calibration standard to produce meaningful comparative results. You will also need to have a way to generate the graphs from the raw data (i.e., familiarity with data graphing software)


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## CelticCross74 (Dec 4, 2014)

my SRA40 does not rattle


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