ZeroHour XD (XM-L2, 3x18650 3400mAh, USB charging) Review: RUNTIME, BEAMSHOTS+more


May 27, 2006


ZeroHour is a new flashlight maker on the market, funded through a Kickstarter campaign. They describe themselves as "modern day adventurers", who want to design outdoor gear that gives the user the ability to adapt to whatever needs may present themselves, and "not be limited by devices that just attempt to look cool."

For their inaugural flashlight, they have opted for both in-light battery charging and a built-in battery backup feature to charge external USB devices. They have sent me their premiere package, known as the ZeroHour XD.

Have they met their stated claim to do it all "without compromising form or function"? Let's find out … :whistle:

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 U2
  • MAX LUMENS: 1,000 Lumens
  • MODES: Low-Med-High-Full + Strobe/SOS
  • LUMENS: 20-400-600-1,000 + 1,000/1,000
  • RUNTIME HOURS: 3400mAh: Approx. 165-13.6-6.6-6.5 / 2600mAh: Approx. 95-7.9-3.8-3.7
  • Equipped with "mode memory" which will return to the last mode used before turning off
  • Strobe/SOS modes hidden: double click to activate self-defense strobe, double-click again to activate SOS
  • BEAM THROW: Approx. 420 meters (600-1000Lm)
  • BATTERY: Up to 3 x 18650 3.6/3.7 Lithium-Ion,
  • mAh: 10,000+ (3 x 3400mAh 18650) / 7,800 (3 x 2600mAh 18650)
  • MATERIAL: Anodized 6061 Aircraft Aluminum Alloy
  • FINISH: Type-III Hard-Anodized Anti-abrasive
  • BEZEL: 304 Stainless Steel
  • INTERNALS: Gold-Plated
  • PROTECTION: Rev. Polarity / Overcharge / Auto-Off
  • REFLECTOR: Orange Peel Reflector
  • SWITCH: Electronic Side Switch
  • LENS: Toughened Glass
  • O-RINGS: Black / Red Silicone
  • TEMPERATURE RANGE: 0-40 degrees Celsius
  • WATERPROOF: IPX8 1 meter
  • DIMENSIONS: 2.28" x 7.28"
  • USB OUTPUT: 1.5 Amp / 2.1 Amp
  • UL CERTIFIED: Battery and Wall Charger
  • Use the included USB cable and AC adapter plug
  • Plug the included USB cable into your desktop computer's USB port
  • The batteries can be removed and placed into any lithium-ion battery charger that supports 18650 batteries
  • Uses up to three 18650 lithium batteries (batteries included on XS and XD models)
  • A fully charged ZEROHOUR XD with 10,000mAh of battery capacity can charge most electronic devices with USB charge ports, including mobile smartphones, tablets, MP3 players, digital cameras and camcorders, portable speakers and many Bluetooth-enabled devices.
  • Can function with one, two, or three batteries present
  • Batteries are rechargeable, removable, and replaceable
  • Quality, trusted brand-name cells manufactured by Panasonic
  • Included (XD): Flashlight, Stainless steel bezel, Spare O-rings, USB power adapter, USB charging cable, Carrying bag, Flat cap (2), Open end cap, Carabiner cap, 3x 3400mAh 18650 batteries
  • MSRP: XD: $225, with 3x 3400mAh batteries (X: $155 for flashlight only)







As you can see, the ZeroHour comes in quite the presentation style box, with lots of display windows and specs printed right on the box. Not to mention extras …



My XD version of the ZeroHour comes with all the main accessories for the flashlight, including USB-AC power adapter with removable USB cable, spare o-rings, large nylon carrying bag, small microfiber carrying bag, neck lanyard with break-away clip, two flat cap tailcaps, one open end cap, one double-ended cap, one carabiner cap, 3x 3400mAh batteries, manual, stickers, and quick-start card. :sweat:


Note that by default the ZeroHour comes with a shiny stainless steel bezel ring and switch ring. Sold separately, ZeroHour also sent me an extra body tube, switch ring removal tool, copies of all the various color stainless rings (red, green, blue, gold, and black), as well as red, green, blue and amber filters (to place over the lens to change output color).




From left to right: AW Protected 18650 2200mAh; ZeroHourXD; Olight SR52, SR Mini; Powertac X3000; L3 Illumination X40.

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

ZeroHour (open tailcap): Weight: 387.5g (531g with 3x3400mAh 18650), Length: 173mm, Width (bezel): 58.0mm
ArmyTek Barracuda (XM-L2): Weight 400.8g, Length 264mm, Width (bezel): 64.0mm
Eagletac SX25L3: Weight: 315.9g, Length: 150.2mm, Weight (bezel): 47.0mm
Fenix TK61: Weight: 605.7g (790g with 4x18650), Length: 218mm, Width (bezel): 96.0mm
Niwalker BK-FA01 (XM-L2): Weight: 682.3g (864g with 4x18650), Length: 209mm, Width (bezel): 80.0mm, Width (tailcap): 50.3mm
Olight SR52: Weight: 396.7g (497g with 6xCR123A), Length: 162mm, Width (bezel): 63.1mm
Olight SR Mini: Weight: 285.5g, Length: 126.9mm, Width (bezel): 48.1mm
SupBeam K50: Weight: 645.0g, Length: 230mm, Width (bezel): 90.1mm
Thrunite TN32 (XM-L2): Weight: 655.9g (808g with 3x18650), Length: 201mm, Width (bezel): 79.0mm







The Olight SR52 is probably the closest overall comparable, in size and design – although there are some extra features with the ZeroHour. Build is of a reasonable size for 3x18650, with a good size head. The ZeroHour feels solid and more substantial than some lights in this class.

Anodizing is somewhat glossy, black finish. Knurling on the battery handle is fairly mild, but there are some grip elements in the head, making overall grip pretty good. Body labels are minimal, with bright white lettering.

The switch is raised with a rubberized cover, making it easy to find by touch alone. Switch feel is good, with a firm click and typical traverse.

Let's look at some of the tailcap options:




The light only opens at the head – the integrated battery carrier slides in from this end. But there are a variety of tailcap options included in the package. Threading is identical at both ends of the battery tube (standard triangular cut).

UPDATE SEPT 18, 2014: ZeroHour has just clarified for me what the point is of the double-ended tailcap. It is apparently an extender cap so you can extend your ZeroHour body tube (but in a compartmentalized way). Note that this doesn't allow you to double the connected cells - but it is a way to attach an additional body tube that you can keep sealed at both ends, like so:


The point to this is that you could stuff whatever you wanted in the additional waterproof body tube - extra cells, bandages, water purification tablets, etc. And then have access to them by opening the tube up at whichever end you like.



Think of it as an extended handle for additional carry items in a waterproof container.

Let's take a look at the back of the battery carrier:



The open tailcap on the base model allows access to the charging port and USB ports on the base of the carrier – but is not waterproof. For that, you will need use of the closed tailcaps (e.g., flat tailcap or caribiner tailcap). Screw threads in the head are anodized, so lock-out is possible.

A nice touch is the extra flat (closed) tailcap – due to the common threads, you could remove the head of the flashlight, close this end with the extra tailcap, and simply use this a "backup" battery source to power other USB devices. :)

Press the small button on the base of the carrier to read out the battery voltage of the installed cells.

Let's take a closer look at the carrier:





Shown on the last pic above, the carrier actually comes with a small cardboard disc to lock out the cells during transport (a nice touch). The carrier is arranged in parallel, so you could run the light on a reduced number of cells (i.e., 1x, 2x, or 3x all possible).

Let's take a quick look at the batteries that come with the XD model:



The 3x 3400mAh batteries (presumably based on the Panasonic NCR18650B core) included with this model is how you get up to the "10,000mAh" stated on the packaging. Batteries appear to be good quality, with small button tops.

Like a number of lights I've reviewed recently, the ZeroHour comes with an in-light charging option:




Just connect the small barrel connector to the base of the carrier, and plug the USB cable into the AC adatper (2.1A max charging current). The indicator will now light up to show relative charge status of the batteries.

Please see my charging analysis later in this review for more details on the charging characteristics.

One of the survivalist features of the ZeroHour is the ability to charge USB devices right from the carrier.




The USB port on the left can be used for standard USB devices (e.g. cell phone), the one on the right is meant for high-drain devices (like a tablet/iPad). Just remove the dust plugs to access the port.

I have attempted to charge both standard and high-drain devices from the ZeroHour, and both worked fine. Scroll down for an example of the testing results.

Let's take a look at the head:




The XM-L2 emitter was well-centered at the base of a fairly large and deep reflector – with medium orange-peel texturing. I would expect reasonable throw (but not as great as the deeper smooth reflector options in this class). Scroll down for beamshots. :wave:

User Interface

You control the light on/off by the electronic switch. Turn the light on by a single click of the switch (i.e., press-release). Turn the light off by a press-and-hold of the switch for ~1sec.

Change output modes by clicking the switch when On. Mode sequence is Lo > Med > Hi > Max, in a repeating loop. The light has mode memory, and returns to the last level used after Off-On.

Double-clicking the switch from On or Off gives you the strobe mode. Double-click again to get SOS

To check the charge status of your batteries – or to initiate charging of USB devices through the ports on the carrier – simply press the small button on the base of the carrier.


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

As with all my videos, I recommend you have annotations turned on. I commonly update the commentary with additional information or clarifications before publicly releasing the video.


Current control:

There is no sign of PWM on any level – I believe the light is indeed current-controlled. :)


Strobe is a fairly common 10 Hz tactical strobe.


SOS is similarly fairly typical.

In-Light Charging

Because the AC charger uses a USB connector to the charging cable, I was able to take direct measures of the charging parameters using my Xtar VI01 "USB Detector" (basically a specialized USB current/voltage meter). This model has recently been favorably reviewed by HKJ here.

For charging tests, I started with discharged AW protected 18650 cells, measuring ~2.7-2.8V at rest (i.e., heavily depleted). For all these tests, I left the USB detector in place for all readings. Note that the voltage reading on this device refers to the input voltage (i.e., from the charging brick).

Initial charging current and input voltage:



As you can see, charging started at 1.78A with a typical USB ~5.35V input voltage ("U" is meant to represent Volts on the top display above). Recall that the AC adapter has a max charging rate of 2.1 and 5VDC. I won't bother continuing to show the input voltage, since it doesn't change much over the charge cycle (ranged from ~5.33V at the lowest charging current, to ~5.42V at the highest, consistent with other multi-cell lights I've tested).

The charger quickly ramps up to its maximum charge current and stays there. For example, after 4 hours of charging, the charging current was up to:


~2.1A at this point, which is the max current.

Within half an hour of this point, current had begun to drop (i.e., falls out of constant-current CC phase)


After by 6 hours and 30 mins of charging on 2200mAh cells:


Current had dropped to zero, indicating termination.

Resting voltage of the AW 2200mAh batteries were ~4.16-4.18V at this point. This is very reasonable charging time (i.e., faster than many 3x18650 class lights), with acceptable battery resting voltage at termination.

Note however that on one of my charging attempts, charging completed in under 4 hours. :thinking: When I measured the resting voltage of the batteries, one showed the initial ~3.0V depleted voltage, with the other two having the typical ~4.17-4.18V full charge. Of course, since the charger charges in parallel, it terminates once the highest cell voltage is reached. But it appears that one cell on this attempt hadn't made proper contact, and therefore wasn't charged at all.

I have observed this same problem in another light with a parallel in-light charging setup (the Olight SR52), suggesting that this issue can occur from time to time in such lights. As such, I recommend you re-confirm the voltage of all cells with a DMM after charging (or discharging) the ZeroHour. After all, just as one cell may not have been included in charge cycle, it's possible a cell may not be included in the discharge cycle during use either. :whistle:

USB Charging

As previously mentioned, you can charge both standard and high-drain USB devices from the USB ports on the back of the ZeroHour carrier. Here is an example of a 2nd generation iPad, already at 80% capacity:



Works great, no problem here. :)

Standby Drain

A standby current drain is inevitable on this light, due to the electronic switches on the head and carrier. As the body design appears, the three wells are run in parallel (i.e. 1s3p arrangement).

I measured the drain at the head (which should take into account both switches) as 0.9mA on my ZeroHour. Given the parallel arrangement, that would translate into nearly 16 months to completely drain fully-charged 3400mAh cells. This is reasonable, but I recommend you twist the head a quarter turn to break the main switch standby current when not in use.

Note that there will always be a small standby current from within the carrier itself. You can only break this one by removing all the cells. But I have measured it to be a suitably low 40uA. For 3400mAh cells, that would translate into 29 years before 3 cells would be fully drained within the carrier.


And now, what you have all been waiting for. ;) All lights are on AW protected 18650 2200mAh. 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.









One comment to start – the Max output of the ZeroHour is rated at 1000 lumens, which is bit lower than many 3x18650 flashlights. It is more consistent with the high-end of the 1x18650 class. The reason for this is the apparent intent to allow the light to function equally well on 1x, 2x, or 3x cells.

Throw is reasonable for the output and size. Scroll down for actual beam output measures.

Testing Method:

All my output numbers are relative for my home-made light box setup, as described on my 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 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).


I've included only 2x, 3x and 4x 18650 lights in the comparisons above, but the max output of the ZeroHour is actually in keeping with a lot of the maximally-driven 1x18650 lights as well. This seems to be a deliberate design feature, ensuring you can successfully use the light (in all modes) on 1x, 2x or 3x 18650.

For the max overall output, throw is quite good (i.e., smaller 1x18650 lights are typically in the 20-25K peak intensity range). Basically, I would describe this as being a well-balanced light for throw.

Personally, for an all-purpose emergency light, I would also like to see a Moonlight mode, or at least a low single-digit lumen level mode.

Here is a breakdown of the estimated lumen values for each level in my testing:


Specs seem pretty accurate with my testing results.

Output/Runtime Graphs:

As usual, all my runtimes are done under a cooling fan, and AW protected 2200mAh cells are the standard cells used in all my runtime testing.

Let's start with a runtime comparison, on my standard 2200mAh cells compared to the supplied 3400mAh ZeroHour ones:


First thing to note is that there is very little difference between Max and Hi runtimes, as the ZeroHour steps down from Max to Hi after about 5 mins. This is why the orange (Hi) and red (Max) runtimes on 3400mAh look virtually identical.

A second thing to note is the rather odd behavior on Hi and Max with 2200mAh cells. In both cases, the light "reset" its output level at some point in the run, jumping back up to a more typical Hi level. I don't know if this issue was specific for my 2200mAh cells, or if it was a more general random occurrence. It could be related to a contact issue with one of the cells/wells (see my earlier comments about one well not recharging on one charge cycle). Perhaps the shorter 2200mAh are more likely to experience this. :thinking:

In any case, a general observation is that the ZeroHour cannot maintain flat regulation for very long on Hi for lower capacity batteries. The light also doesn't seem to maintain flat regulation at all on Med (i.e., looks like a more direct-drive-like pattern). This is certainly not an issue in actual use though, as you would not notice this slow drop-off in real life.

Let's see how Max output looks on reduced number of batteries (using 3400mAh ZeroHour batteries)


As you can see, the light still runs fine – even on Max – with as little as one 18650.

To compare relative efficiencies, let's look at some competing lights – all on my standard 2200mAh cells.




Although the ZeroHour is not as flat-regulated as some of the competition, overall output/runtime efficiency seems very good at all levels. Some of the excellent current-controlled circuits (e.g., Fenix) may have a slight advantage, but the ZeroHour does seem to be in the general range of other good models (e.g. Olight and Thrunite offerings).

On a final note, ZeroHour informs me that the current version of the charger cannot re-start protected cells once the protection circuit has tripped. You would need to use an external charger if that were to happen. But given the slow direct-drive-like pattern of the runtimes, it is highly unlikely that you would drain your cells that far down – it never happened in any of my testing, for example.

Potential Issues

I experienced some intermittent contact issues with one well when charging my standard 2200mAh cells inside the light. This may also explain the unusual runtime patterns on the Hi/Max mode runtimes (i.e., one cell may not have been consistently engaged). I suspect cell height may be a contributing factor here - although I have seen this occur on other multi-cell lights run in parallel. As such, I recommend you check the charge status of each cell separately before and after charging/discharging in the light.

There is stand-by current due to the electronic switch in the head, but this is relatively low (i.e., 16 months before the supplied 3400mAh cells would be drained). You can break this current and lock-out the light by a simple twist of the head. Note there is a secondary drain inside the carrier, but this is so low as to take many decades to drain the cells.

The light is not water-proof if you use the open ring tailcap (i.e., to have access to the USB and/or charging ports). I recommend you use one of the fully closed tailcaps when in general use.

There is no ultra-low mode to speak of (i.e., lowest level is ~20 lumens).

Light is relatively large and heavy for an outdoor/survival light (although it does store up to 10,000mAh of charge).

Preliminary Observations

The ZeroHour is a solidly build flashlight, with a lot of features designed to appeal to the more survivalist-minded outdoor enthusiast. In particular, its "backup battery" USB charging features is particularly well executed. It also has a nice range of functional and cosmetic accessories.

My first comment is about the size – although meant to be run in a 3x18650 arrangement, the light can function just fine on 1x or 2x18650 cells. This means that the ZeroHour is a hefty light – and one that may not be quite as bright on Max as you would expect for a light this size (i.e., it is actually within the same range as maximally-driven 1x18650 lights).

But this actually provides an advantage of sorts, as it relates to the use of the parallel cell arrangement here. Parallel is inherently safer than series for in-light charging. :thumbsup: However, I have previously observed on a number of lights with this parallel arrangement that a given well/cell may not consistently engage during a charge or discharge cycle. As such, you may be missing out on the capacity of one of the cells during use (or not fully recharging). :shrug: In the case of the ZeroHour, it specifically occurred only on my AW protected 2200mA battery tests, making me think the shorter height of those cells could be a contributing factor. But here's the key point - since the maximum discharge rate of the ZeroHour (when running as a light, or using the "battery backup" USB feature) is not excessive in any mode, it doesn't pose a safety risk on this light should a cell not engage.

The "battery backup" feature of the light is quite nice – especially the option to charge both standard (<1.5A) and high-drain (<2.1A) USB devices. :thumbsup: Indeed, you can even charge from both ports simultaneously. You don't even need to bring the head along with you if you don't want to use it as a flashlight – just pop an extra closed tailcap cover at the other end of the battery tube, and you have a portable >10,000mAh battery charger. :wave:

While the ZeroHour really is designed to serve as an all-purpose emergency system, its flashlight functions are quite good. You have a good range of output levels (although I would like to see a lower Lo). You have a good beam pattern with decent throw (more throw than 1x18650 lights, but less than some 2x/3x 18650 lights). And the current-controlled circuit provides for good efficiency without the "flicker" of PWM (although the light is not as flat-stabilized as some of the current-controlled competition).

At the end of the day, I think they have done a good job in balancing the potential needs and perspectives of a well-equipped outdoor enthusiast. A one-size-fits-all system is never going to be optimized for everyone's needs (i.e., higher or lower output could be required, lower weight, etc.). But as a multi-function tool for someone already carrying a bit of kit with them, I think it serves a good general purpose role. If they are considering a second flashlight offering, I would encourage ZeroHour to compliment this model by offering a more scaled-down, lighter-weight, lower output option for the minimalist outdoors-person. :wave:


ZeroHour XD provided by ZeroHour for review.
Last edited:


May 27, 2006
ZeroHour has just clarified for me what the point is of the double-ended tailcap.

It is apparently an extender cap so you can extend your ZeroHour body tube (but in a compartmentalized way). Note that this doesn't allow you to double the connected cells - but it is a way to attach an additional body tube that you can keep sealed at both ends, like so:


The point to this is that you could stuff whatever you wanted in the additional waterproof body tube - extra cells, bandages, water purification tablets, etc. And then have access to them by opening the tube up at whichever end you like.



Think of it as an extended handle for additional carry items in a waterproof container. :wave:


Flashlight Enthusiast
Jun 12, 2013
Thanks for another great review, selfbuilt!

With many of us having multiple digital devices nowadays, this has been a useful flashlight for me as a general use light and device charger. Whilst there have been a number of knock offs in the market, the ZeroHour X is a well made and solidly built flashlight.


Flashlight Enthusiast
May 23, 2008
Great review as always!! I can't believe how I missed this on KS, I am a regular backer and I have supported flashlight and related projects such as the Hexbright, opensource battery charger and solarade.

Three thing that drives me crazy: They call this a "survival flashlight", but it lacks a true low mode for extended runtime, a beacon mode (has strobe but no beacon?), and instead of the round DC input they could have used micro USB which is fair more common, lets say what happens if a solar panel is being used to charge the light and the provided cable breaks?

These could have been integrated to the product without affecting the design or manufacturing cost at all. A bit expensive, but seems well made and to have efficient internal circuity. Would consider buying to use along a solar panel.


May 27, 2006
A bit of a different light - glad those of you who noticed the review enjoyed it. :wave:

Three thing that drives me crazy: They call this a "survival flashlight", but it lacks a true low mode for extended runtime, a beacon mode (has strobe but no beacon?), and instead of the round DC input they could have used micro USB which is fair more common, lets say what happens if a solar panel is being used to charge the light and the provided cable breaks?
All really good points. I'm a sucker for a nice ultra-low mode myself. And I can fondly remember a time when slow signalling strobes and beacons first started becoming available on lights - only to be crowded out by tactical strobes in short order. Nowadays, I'm even getting keychain AAA lights with tactical strobe modes on them. :rolleyes:


Nov 2, 2009
I really like the idea of having an 18650 charger, battery back up and light all in one product!

I'm always traveling, spending time in remote areas and while trying to keep the weight down as much as possible I do like to have:
- 1 larger light with decent throw
- Something to charge 18650's
- Battery backup

My mythical dream light I've often envisioned before was a Fenix TK75 with:
- moonlight and low mode
- ability to charge batteries
- ability to use as a power pack for both 5 & 12 volts
- with high drain cells ability to trickle charge motorcycle battery

Oh yeah make the whole the whole thing 5x more tougher and reliable!

I'm glad to see these guys are doing this. Though it might not be my favorite beam pattern in a light, and certainly lacks modes I often use if it was reliable I might get it anyways for the sake of being able to leave the battery charger and back up packs home!


Newly Enlightened
Jan 6, 2015
I'm new here. What a fabulous review! Where have you been my entire flashlight addicted existence?! I've got a lot of catching up to do here.

At CES in Las Vegas today, ZeroHour just announced Kickstarter campaign number two! The ZeroHour Relic XR. Here's the link. There is a (IMHO) decent early bird option available for $130 USD. For more on this here is the link:

It seems that ZeroHour has done a good job of responding to early adopters (i.e. Flashlight Geeks) and they've done away with the infernal semi-proprietary charging plug on the unit in favor of a micro-USB thank goodness! I bought another charging cable because I know I'm going to lose the original eventually. I'm bummed at the prospect of having to carry two different charging cables in the future but that's the breaks for living on the edge. As you'll see this is a smaller, more compact version of the Big XD and will be for those that have wanted an EDC version and something that could be mounted to weapons. Of course the charging capacity is way down but this little pup will allegedly still provide a full charge for any smart phone. I'm all about eliminating redundancy and I think ZeroHour has it just right in that regard.

I've been using the ZeroHour XD for about 4 months now. It took me a while to find the time to unbox and go through the numerous parts and accessories included in my "package". But once I did was I very impressed. Straight up this has become my go to flashlight around the house fpr the big jobs and it replaces my trusty Surefire P1R Peacekeeper which is now relegated to the truck. I have three black labs and need to scan my property for skunks before I let them out at night as I am bone weary of having to deskunk them. Yes, you'd think they'd learn and one has but the other two are what we call "meth labs" and just have to mix it up whenever there's an opportunity to protect the property. I lost count at 10 late-night deskunk sessions this last year when I was using the P1R. I have also had to contend with them wanting to munch on other night-roaming mammals. Now I climb up on a high point of my property and scan the area BEFORE I release the hounds and in four months I've spied numerous skunks, possums, raccoons and coyotes that could have tangled with my dogs and have not had to mix a batch of deskunking brew that entire time. The bright, broad beam of the XD causes these critters to skulk off pronto! The original reflector throws a relatively wide beam. I just bought the optional reflector that will tighten it up and provide a longer throw and I expect that I'll install that on my new XD (just ordered as part of a combo pack on the Kickstarter campaign and I highly recommend this as it's a terrific value!) will be helpful for reaching the far recesses of my property as well as help me to find the possums hanging out in my trees that seem to wait until I go to bed to start fighting with each other. I've found bottle rockets tend to do a good job of dissuading them from getting comfy. But I digress...

I've taken the XD on the road with me a couple of time this last fall, once to Kauai and the other to a mountain retreat. Both times we had weather that cause power outages and both times I used this opportunity to try out the charging capacity of the XD. During a mountain retreat last week we got a freak snowfall here in Southern California and of course the power lines snapped where I was at about 8 pm so I plugged in an iPad with 10% charge remaining and got it up to 100% in less than 2 hours with enough charge left that the flashlight had 30 minute of high output light left. I was amazed. Problem was that without wifi the iPad was mostly useless without wifi ... until I set up a hotspot with my phone. My new Verizon plan allows me to do this now at no charge. Problem solved. In this case this flashlight system allowed me to get some work during an outage so I didn't have to cancel my following day plans. Nice.

I noticed a couple of you missed the original Kickstarter campaigns for this original ZeroHour XD so here you go ... the early bird gets another shot at the worm. Again, the last option gives you the opportunity to buy both the original XD reviewed here and the upcoming Relic XR (Due Q2) at a deep discount relative to future retail and if you're looking for the best of both worlds, tactical and preparedness this is a solid option for you. If you're at CES now, by all means go look them up! Cheers from San Diego.

Oh, and I look forward to your review of the Relic! Thank you.


May 27, 2006
I'm new here. What a fabulous review! Where have you been my entire flashlight addicted existence?! I've got a lot of catching up to do here.
Thanks , glad you enjoyed the review - and :welcome:

The inaugural ZeroHour light was certainly interesting, and I am looking forward to seeing what they come out with next. I had recommended they consider a more compact model for everyday uses, and the Relic may fit the bill. We'll see ...


Newly Enlightened
Jan 6, 2015
Selfbuilt - thanks for the reply and the greeting. Really pleased to have found y'all!


Newly Enlightened
Dec 17, 2002
Concord, CA
They seem to be going after some of the TAC market with the light now, which is probably a good thing for reaching a wider market.

The XDR seems like a very nice light but the but I was hoping to find more commentary here on the beam switching options.

For most people who want the strobe and hi/lo functions I think something with fewer clicks and manipulations would be optimal. If they haven't ordered a lot of the parts yet they still have time to change these things before the KS closes and make the light way more interesting for the tac audience.

Thoughts on optimized button scheme?
One click = low
double click = high
Press and hold = strobe
half press and hold = low
other modes can be accessed via the more complicated ring.

Right now having to click once for low and then clicking twice more (or just clicking three times) to get to the High beam seems like extra unnecessary steps. For a tac user things that are complicated or take more time to execute drastically reduce the usefulness of the light.

But I love the idea of a combined handheld device that uses standard Li rechargeables for both USB and effective lighting.
Last edited:


May 27, 2006
For most people who want the strobe and hi/lo functions I think something with fewer clicks and manipulations would be optimal.
Yes, most tactical people definitely want single press/click action for max (and maybe strobe). It's hard for me to comment on an interface until I've seen it in person, but I'm sure they could use all the feedback from members here that they can get.


Newly Enlightened
Jan 6, 2015
I'm not as deep into TAC market as many of you but I do strongly agree that Aaron at ZeroHour can and should pause long enough to consider the "button scheme" before he bakes the ZeroHour Relic XR. My sense is that the two principals, Amy and Aaron (I've forgotten their last names - they can be found on their Kickstarter page) are exceptional at critical functions like marketing, manufacturing, sourcing and testing and excel at getting quality tech built in China, but could really benefit from help and suggestions for subtle but critical design features. I may be wrong, they may have someone on the downlow that drives form v. function there. I've taken the liberty of cutting and pasting contact info below in case any of you would like to reach out. If you invest in their Kickstarter campaign you also have the option of leaving them an online comment but my experience has been that they are very willing to take a call. One thing I found telling was ZeroHours decision to participate in the recent Consumer Electronic Show in Vegas where they got to run with the digerati and their apparent decision to forgo the SHOT show in Vegas in a few days. Surefire will be at SHOT but didn't see any reason to do CES. That's interesting and revealing.

Anyway, here's hoping one of you will consider dropping a dime or a digit and "poke" Aaron. Again, his contact info follows. The support email address goes straight to him.

As for the button/click scheme, I think you have it right @Rokit88 if in fact a click strategy is the way they go. I'm still marveling over the little Black Diamond Voyager mini lantern a buddy gave me for Christmas and how it provides complete control over the brightness (lantern and spot) with a full button dimmer. I could get used to that on certain flashlights - not all. For a smaller light like the Relic XR, I think it would be perfect. For my larger workhorses, I want to be able to boost brightness quickly of course and don't want to wait for the full cycle up.


Mon-Fri 12Noon - 7PM | Sat 1PM - 6PM (California / PST Time)
Toll-Free: (844) 200-ZHXD (844-200-9493)
Direct: (562) 395-3922

EMAIL SUPPORT:General Questions: [email protected]
Gmail Chat: [email protected]
Wholesale & Drop Ship inquiries: [email protected]


May 27, 2006
That Kai light does indeed look similar. However, while it's hard to tell from the pics, it also looks to have lower build quality.

Given the apparent similarities, I wouldn't be surprised if they were sourcing some materials from similar suppliers - but that doesn't mean they have the same performance or reliability. I've seen many examples where a given brand orders a custom component based on specific design specs, and the supplier then releases (or already has) a cheaper variant available in other markets (or a competitor with similar underlying tech, etc.).

I no longer typically do so-called "budget" light reviews (for the reasons outlined on my FAQ page). But having handled a lot of "clone" or "budget" versions of established brands over the years, I can say that these sometimes offer pretty close performance - and sometimes drastically worse. You would really need to compare both lights under the same conditions.


Newly Enlightened
Sep 26, 2009
I had looked at this light with interest but wished it had a low of around 1lm. The X version is $70.00 less and comes minus batteries and the carabiner tail cap. A less expensive option for those who already have batts. What was the OAL of the 18650s included with the XD? Knowing this maybe slightly longer cells would help with the continuity problems encountered with the charge/discharge problems of the one cell.