JetBeam PA40 (XM-L T6, 4xAA, Carbon Fiber body) Review: RUNTIMES, BEAMSHOTS, & more!

Originally posted: August 1, 2011
Last Revised: August 21, 2011
Warning: even more pic heavy than usual.

It’s nice to see some attention brought back to the 4xAA polymer-style flashlight. The old lux I-based Streamlight ProPolymer 4AA Luxeon was a favourite of many old-timers here (well, those of use who joined before 2006 ). Of course, at a whopping 42 lumens and 3,500 lux @1m, the old single-stage ProPoly is a little out of date now. Let’s see how this new Jetbeam PA40 model compares.

Manufacturer Specifications:

I like the packaging – distinctive clamshell presentation case.

Inside, in cut-out foam, you will find the light, wrist lanyard, spare o-rings and boot cover, as well as a basic quality holster with closing flap (very similar to some recent Fenix lights, but open at the bottom in this case). Also included is a (refreshingly) detailed manual and warranty card.

This is also one of the rare times I’ve seen moisture-guarding silica gel packs included with a light.

From left to right: Duracell AA alkaline, Jetbeam PA40, Fenix LD40, Streamlight ProPolymer 4AA Lux, Sunwayman M40A.

All dimensions with no batteries installed:

JetBeam PA40: Weight: 184.0g, Length: 183mm, Width: 40.8mm (bezel), 42.1mm (max width)
Fenix LD40: Weight: 185.5g, Length: 184mm, Width: 41.1 (bezel), 42.4mm (max width)
Streamlight ProPoly Lux: Weight: 121.0g, Length: 179mm, Width: 39.9 (bezel), 42.8mm (tailcap grip ring)
Sunwayman M40A: Weight: 247.0g , Length: 145mm, Width 57.0mm (bezel)

Notice a lot of external build similarity between the PA40 and Fenix LD40? I’ll have more to say about this at the end of this build section. Let’s focus on the PA40:

I really like the feel of the composite body on the PA40 – I can believe the carbon fiber claim, as it feels tougher and more durable than typical composite/polymer/plastic bodies I’ve held. The head is aluminum, but the anodizing (type III = hard anodized) is a near perfect match to the color and sheen of the composite body – both are a well done matt-black finish. Lettering (which is minimal) is subtle but clearly legible in light gray.

Although the light doesn’t have knurling as such, there are a lot of grip elements on the handle. Grip is very good - certainly much improved from the old Streamlight ProPoly.

Square-cut screw threads are anodized for head lock-out (although it takes a full one-and-a-half turns of the head). There are a good number of threads – you won’t accidentally open up this light, and the head still fits on firmly when locked out. Light cannot tailstand.

It looks like there is a substantial heatsink in the head. This is important, as the cabon fiber/composite body will likely not contribute significantly to heat dissipation.

Rear tailcap boot cover connects with a forward clicky switch built-in to the battery carrier. There is also a small frosted window below the main panel on the back, through which you can see the red LED on the battery carrier (which flashes or glows red to warn of low battery power - see my UI section for a discussion).

Battery carriers are always the weakest part in any light that uses them. The all-plastic carrier here seems decent enough (I’ve seen better, but I’ve also seen much worse). Batteries fit securely within the carrier. There is no rattle with the light fully assembled.

Comparison to the Fenix LD40

As mentioned above, there is a huge build similarity to the Fenix LD40 – to the point where I’ve discovered that the head and battery tubes fit on each other’s bodies! Here are some detailed pics to show you what I mean (PA40 on the left or top in each picture):

Some have commented that the PA40 is a "version 2.0" of the LD40 body, which is a fair comment (although maybe more a version 1.2?). I like the fact that there are no longer external screws holding the back plate to the handle. But the major improvements are in the grip and carbon fiber body on the PA40 – it feels and looks like a more rugged light. Aside from those changes, most of the others are really more incremental improvements to the common design (keep in mind, the LD40 was released over six months ago).

Still, the fact that the parts are interchangeable suggests to me that Fenix and Jetbeam have either sub-contracted out this aspect of manufacture to the same supplier, or the in-house designers have moved from one company to the other.

The PA40 uses a fairly heavily textured reflector, with reasonably deep proportions for the size of the head. I would expect reasonable throw with a fairly smooth beam. XM-L emitter was well centered on my sample.

Here's a comparison to the LD40 (PA40 on the left, LD40 on the right).

Overall reflector dimensions look pretty comparable.

Which brings me to the white-wall beamshots. All lights are on 4x Sanyo Eneloop NiMH, 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, except for the Neutral LD40 (which was set to Daylight white balance for comparison). All beamshots taken immediately upon activation.

The PA40 clearly puts out a lot more light than the Fenix LD40, but isn’t as much of a thrower (as you would expect). Output seems similar to my MC-E-based Sunwayman M40A. There is something of a grenish tint-shift in the corona around my PA40's hotspot, but it's not noticeable except up-close (this not uncommon on XM-L lights, in my experience).

UPDATE AUGUST 21, 2011: I have now done 100-yard outdoor beamshots, in the style of my earlier 100-yard round-up reviews.

User Interface

The UI of the PA40 is familiar, but slightly different from most lights in this class.

Activating the light is simple enough - from Off, soft-press the forward clicky for momentary on, click for locked-on.

To change modes once On, you need to click the light off-on quickly to advance to the next mode. Interestingly, you can advance modes from Off by simply doing repeated soft-presses of the switch (clicks also work, but are not required). But from On, you need to do the actual click off-on.

Since flashing the light causes the mode to change, signalling isn’t possible. Mode sequence is different from most lights as well: Turbo – Hi – Med – Lo, in repeating sequence. Light has mode memory, and retains the last setting used for the next time you turn on.

According to Jetbeam once the batteries reach ~50% power for a given mode (when On), the red light warning indicator will flash three times in three seconds, repeating every ten seconds. When the batteries are nearing exhaustion, the indicator will flash continuously until the batteries are dead. I can confirm that the warning light does indeed come on ~50% into the regulated lifespan of fresh NiMH or alkaline on my sample (scroll down to my runtime graphs).

There is a really nice feature here – I have found that the battery indicator activity is dependent on the output mode of the light. So, for example, on nearly empty batteries, you will get constant flashing on Turbo, three flashes every ten seconds on Hi, and no flashes on Med or Lo. This is actually a useful way to indicator how much relative runtime is left for a given mode

No PWM/Strobe

No sign of PWM at any level of the PA40, leading me to conclude it is current-controlled.

No blinky, no stroby on the PA40.

Testing Method:

All my output numbers are relative for my home-made light box setup, a la Quickbeam's method. 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 recently devised a method for converting my lightbox relative output values (ROV) to estimated Lumens. See my How to convert Selfbuilt's Lighbox values to Lumens thread for more info.

Throw/Output Summary Chart:

Effective November 2010, I have revised my summary tables to match with the current ANSI FL-1 standard for flashlight testing. Please see for a description of the terms used in these tables.

Output is reasonable for a XM-L equipped 4xAA polymer light – roughly comparable to my Sunwayman M40A (MC-E version), and certainly a lot higher than the XP-G-based LD40 (or the Lux I-based ProPoly ). They seem to be driving the PA40 to a reasonable level. I don’t know how the new M40A XM-L version compares, but I imagine it is brighter on max.

Throw is reasonable, but not as far as the LD40 or M40A. This is expected for a XM-L emitter with a reflector this size, driven to these levels on the PA40.

Output/Runtime Comparison:

On Turbo/Max, there is a nice gain in efficiency for the PA40 compared to the MC-E-based M40A – nearly twice the runtime for the same max output. A similar efficiency gain is expressed differently compared to the LD40 – on Turbo, runtime is generally similar, but with much greater output on the PA40. In fact, on Hi (one down from Turbo), the PA40 is about as bright as the LD40 on Turbo – but with two and half times the runtime.

As advertised, the warning light came on ~50% into the regulated portion of the Turbo runs above (i.e. at just over 50 mins on Eneloop, and just over 20 mins on alkaline). Note that is with reasonably new cells - on older NiMH with a lot of cycles, the warning light may come on earlier.

Potential Issues

Light uses an all-plastic battery carrier. Still, it seems reasonable quality (i.e. toward the higher end of all-plastic carriers that I’ve seen).

Need to click Off-On to change modes (from On).

Takes a full one-and-a-half turn of the head to lock out the light.

Light can’t tailstand.

Preliminary Observations

The 4xAA market has been rather underserved until recently, with relatively few good quality options in this size. I’m happy to report that the PA40 is probably the best quality composite body I’ve seen yet. It is definitely a physical upgrade from the decent Fenix LD40 (with which it seems to share a common ancestry). The PA40 has excellent performance and good features all around, including an innovative battery life indicator.

The composite body is interesting – I can believe the reinforced carbon fiber claim. It looks rugged, and the feel and grip are good. The unit is well balanced in the hand (with batteries loaded). Switch and interface are easy to handle/use, once you understand how it works (no momentary signaling, though). I would have no trouble recommending this light to non-flashaholics, although I can see how some might prefer the interface or throw of the original LD40 build. The PA40 presentation case is snazzy too.

Heatsinking is always a concern on polymer lights, but the PA40 seems to have a substantial mass in the head to help compensate. Max output at ~460 estimated lumens in my testing is consistent with manufacturer specs. While this may not be as high as some recent XM-L lights, it seems a prudent drive level for a 4xAA polymer body light.

Spacing of output modes is good, with three standard output levels and an additional moonlight mode. Performance/efficiency at all levels seems excellent in my testing – Jetbeam is clearly using a good-quality constant-current circuit. It’s also nice to see Jetbeam’s specs are not inflated for either output or runtime (note their runtime values based on 2500mAh batteries, I used 2000mAh Eneloops in my testing).

I do have some quibbles - tailstanding would be nice, as would the ability to signal in momentary. The later would require a redesign with a secondary switch (i.e., something like the original LD40 interface). The battery indicator located in its place here is an acceptable trade-off to my mind, as it actually provides useful contextual information for the output mode you are in.

The PA40 is a very good overall build for a XM-L-based, 4xAA composite-body light. Jetbeam has clearly built on the design of earlier models to deliver a well-thought out package, with a few innovations to boot.


Jetbeam PA40 provided by Jetbeam for review.

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