Lumintop SD10 (XM-L2 NW U2 – 1xD 3xAA 1×26650/32650) Review: RUNTIMES, BEAMSHOTS+

Warning: pic heavy, as usual.

The SD10 is a new XM-L2 light from Lumintop that supports a wide range of voltage/battery sources. Basically, you can run the light on 1×3.7V Li-ion sources (designed for 32650, but 26650 or even 18650 could be used), 3xAA, or 1xD-cell.

For this review, I actually have two SD10 samples on hand – the originally launched SD10 (Cool white tint) and a new revised model (Neutral white tint). There have been a few build changes as well in this revised model (most notably in the switch and reflector designs). To allow you to compare this new release to the early samples that other reviewers have published on, I am including comparisons of both models in my testing below.

Let’s see how they do …

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

CREE XM-L2 – Cool White T6 LED (originally reported) or Neutral White U2 (3C tint) LED (currently provided)
One of the world’s smallest, lightest and brightest 32650 searchlight.
Compatible with a wide range of batteries through intelligent control, and thus it has different outputs based on different battery types.
Max output reaches up to 800 lumens.
Output/Runtime 1×32650: 800lm/7.5hr, 100lm/26hr, 10lm/280hr
Output/Runtime 3xAA: 500lm/6hr, 100lm/15hr, 10lm/150hr
Output/Runtime 1xD: 200lm/7.2hr, 30lm/80hr, 2lm/60days
Beam Intensity: 17,000cd
Peak beam distance: 260m
Coated tempered window resists impact.
Aerospace aluminum uni-body design combined with a stainless steel retaining ring offers superior impact resistance. Mil-Spec hard-anodized. O-ring Sealed.
Front side switch.
Superb heat release system provides excellent heat transport capacity.
Slip-resistant body design.
Lengthened lanyard hole with tail-standing design.
ANSI FL-1 Waterproof to 2m
ANSI FL-1 Impact resistant to 1.5m
Dimensions: Length 4.69 inches (120.3mm), Width 1.56 inches (40mm)
Weight: 4.03 ounces (11.5g)
MSRP: ~$60

This is an unusual case where the new Neutral white version is a higher output bin than the original Cool white version (i.e., NW is U2, whereas CW was a T6). The launch of the XM-L2 emitter is a little unusual in this regard, as T6 and U2 output bins for both emitter types seem to be concurrently available.

Shown above is the original SD10 (Cool white) that I was sent. The SD10 comes in fairly basic Lumintop packaging – a hard cardboard box with packing foam. Inside you will find the light, extra o-ring, wrist lanyard and manual. No holster was provided with my sample.

I will highlight any build differences between the new Neutral white version and the original Cool white version as we go along. Most of the pics below are of the original Cool white sample

From left to right: Duracell NiMH; Lumintop SD10; Foursevens X10; Eagletac GX25A3; Sunwayman D40A; Olight S35; Eagletac SX25L3.

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

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
Foursevens X10: Weight: 156.9g, Length: 135.5mm, Width (bezel): 46.0mm
JetBeam PA40 4xAA: Weight: 184.0g, Length: 183mm, Width: 40.8mm (bezel), 42.1mm (max width)
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
Olight S80: Weight 162.5g, Length: 151mm, Width (bezel): 38.7mm

The overall build of the SD10 certainly looks similar to a number of recent 4xAA lights (i.e., shares the same length and bezel diameter as a number of them). However, the overall feel of the light is not as polished or solid as the recent Nitecore/Sunwayman/Eagletac offerings. As you can tell from the measures above, the SD10 is considerably lighter than most of those other lights. The aluminum body feels thinner, and the knurling is very mild (i.e., not very grippy). While still acceptable, the overall initial impression is of a relatively high-quality budget build, as opposed to the more mainstream brands.

The light comes in flat matte black finish, hard anodized, with no obvious chips or damage on my samples. Labels are bright and clear – sharp white against the black background. Note the body labels are in a smaller font on the revised Neutral White sample, as shown below:

Screw threading is square cut (or more accurately, trapezoidal), and is anodized for lock-out. Threading feel is good, and seems of decent quality. It’s nice to see the physical lock out, as many carrier-based lights lack this feature.

The SD10 can tailstand easily, thanks to the flat base. There is a small lanyard attachment point in the base.

There is an electronic switch near the head, used to control the light. There is a green LED beneath the switch which serves as an on/off signal (but not a low voltage warning). While the appearance of this switch reminds me of the original Olight S35/S65, switch feel and user interface is different. The initial SD10 switch had no feedback other than the LED (i.e., just a soft, squishy feel – with no tactile or auditory feedback that the switch was pressed). This has fortunately been revised on the new model, which has a proper click now. Traverse is about typical for an electronic switch on this new model.

Note that the user interface is a little unusual the SD10, as you need a sustained press for on/off, and click to change modes (see my UI section below for more info).

If you want to use 3xAA, you’ll need to use a battery carrier.

The bundled 3xAA carrier is very basic, akin to what you would find on a budget light. Note the current carrier is not reversible, and must be inserted in the correct orientation. This design suggests the carrier was more of an afterthought – I would recommend a sturdier carrier be sourced for the SD10.

Let’s take a look at the emitter:

Cool White:

Neutral White:

The SD10 comes with the Cree XM-L2 emitter, in either Cool White (original version) or Neutral white (3C tint bin reported). The XM-L2 emitters were both well centered on my samples

The SD10 reflector is a reasonable size – although not quite as deep as many of the 3x/4xAA lights I’ve reviewed recently. This means you should have decent throw, but somewhat reduced compared to those models.

The original Cool white SD10 I was sent came with a smooth reflector, but the revised Neutral White version has a textured one (i.e., light-medium orange peel). I don’t know if this is standard now, or if both reflector types are available. In any case, the OP texturing helps to remove the few beam rings I noticed on the smooth reflector version, and softens the margins on the hotspot. Scroll down for beamshots.

The light has a flat stainless steel bezel.

User Interface

The interface is a bit different from most lights in this class – you turn the light On or Off by a sustained press and hold of the electronic switch (i.e., hold it down for >1 sec). The green LED below the switch lights up while it is pressed. The revised model has a definite click now.

Once on, a simple click (i.e. quick press and release) of the switch will change modes. Click the 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. Note the light has mode memory and remembers your last choice (even after turning off/on).

Strobe is accessed by doing a quick double-click of the switch when On. There is no memory for strobe mode (i.e., always returns to the constant output mode on re-activation).



The SD10 uses visible PWM (pulse width modulation) at the Lo and Med level.


Med PWM:

As you can see, the SD10 uses PWM of ~935-940 Hz. This is unfortunately visible, and may be distracting for those of you who are sensitive to it. There is no PWM on the Hi mode.


The strobe is a fairly standard fast “tactical” strobe of ~9.5 Hz. You will note however that there is a secondary pattern to this strobe. Here is a blow-up:

What you are looking at here is the PWM effect in the on-phase of the strobe. Basically, the strobe is not a full-power strobe – as you can see above, the light cycles off for a brief period, according to the PWM frequency. The light does spend most of the PWM duty cycle in the on-phase though, so it will appear to be pretty close to a full-power strobe.

Standby Drain

A standby current drain is inevitable on this light, due to the electronic switch. I measured a consistent drain of 254uA for both 3xAA and 1×3.7V Li-ion on the original Cool white SD10, and 261uA on the new Neutral white version. At those rates, it would take a little under a year to drain 2000mAh Sanyo Eneloops, or over two and half years to drain a 6000mAh 32650 battery.

This is not unreasonable for an electronic switch. If you are concerned, you can easily lock-out the SD10 by a quick twist of the tailcap.


And now the white-wall beamshots. Lights are about ~0.75 meter from a white wall (with the camera ~1.25 meters back from the wall).

Note that automatic white balance is used on the camera, to minimize tint differences (i.e., in real life, the Neutral white version is a lot warmer – see my video for a better tint comparison).

Let’s start with comparisons between the original Cool white (on the left in the beamshots below) and the new Neutral white (on the right).

Sanyo Eneloop (2000mAh):

26650 3.7V Li-ion:

Again, you cannot make any conclusions about tint from the above pics, due to the auto white balance. Subjectively, my Cool white version is fairly cool (and slightly purplish), and the Neutral White is a believable 3C tint, as reported.

There were a few beam rings noticeable on the original smooth reflector/Cool white version of the SD10 – these are no longer present thanks to the texturing on the new OP/Neutral white reflector. The other main difference is the OP reflector smooths out the edges of the hotspot now (i.e., no longer as sharply defined on the OP version, with a wider corona present). Overall peak centre-beam throw is not really affected by the texturing. I personally prefer this textured Neutral white version.

As you can probably tell above, there is not much of an output or throw difference between the new Neutral white SD10 and the original Cool white. Scroll down for some detailed comparisons.

For comparative beamshots to other lights, I am using the Neutral white version, as it is the most recent.

Sanyo Eneloop (2000mAh):

As expected, SD10 beam is not quite as throwy as the other recent 3x/4xAA lights, and has a wider spillbeam. But it is hard to compare the beamshots above because the max output of the SD10 is lower than those competing lights. Scroll down to my output/runtime tables and graphs for more info.

26650 3.7V Li-ion:

Much the same observation for the SD10 on 26650, compared to other lights in that battery class.

As an aside, I personally like the 3C tint bin of the new Neutral white SD10.

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 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).

Let me start with a comparison of estimated lumen levels on both lights, on all supported battery types

As you can see, there is not a great difference in output levels between the original Cool white sample (T6 output bin) and the new Neutral white (U2 output bin). But keep in mind that output bins represent adjacent output ranges, so it’s possible to see little difference (i.e., a high-end T6 and low-end U2 would be virtually indistinguishable).

My output estimates are generally pretty consistent with Lumintop ANSI FL-1 specs. The main difference is that the max output on 3xAA is higher than the Lumintop specs, and max output on 26650 (which would be the same for 32650) is lower than the reported specs.

But note as well that there is a significant step-down on this light (i.e., the number in brackets, at 5 mins post-activation). Please see runtimes below for more info.

Let’s see how the SD10 compares to the multi-AA and single 26650 class lights.

As you can see above, max output and peak intensity throw on my SD10 samples were lower than my other recent 3x/4xAA lights. This is consistent with what you saw in the beamshots.

Basically, my results show that there is relatively little difference between 3xAA and 3.7V Li-ion output levels on the SD10.

Lumintop peak throw intensity measures seem quite accurate in my testing.

Output/Runtime Graphs:

Ok, let’s start with a general battery comparison (beginning with the Cool white version):

As you can see, there is not a great difference in output between 1×26650 and 3xAA. The main difference is in runtime and regulation pattern (i.e., alkaline can’t hold output levels flat for as long, but will run longer overall). Note that 1×32650 would provide even greater runtime, due to the higher capacity of those larger cells.

As you would expect, output is lower on a single alkaline D-cell.

Let’s take a closer look at the first few minutes of continuous runtime:

There is a timed step down after 4 mins of continuous runtime on 1×26650 or 3xAA (but not 1xD). Like some of the recent Olight lights, this step-down takes place over a couple of minutes (i.e., is gradual enough that you can’t see it happening).

What about the new Neutral white version?

Basically, there is no real difference in runtime between the Cool white T6 and Neutral white U2. As previously reported, there is a slight increase in output on the Neutral white version, but it is pretty negligible between my two samples.

To compare to other lights in their respective classes, let’s start with AA:

I don’t have a lot to compare it to here, but you can see that the SD10 seems reasonable for the output level. Again though, the light really shows a partially-regulated pattern – and there is a very significant step-down on max.

Potential Issues

The SD10 uses visible PWM on its Lo and Med modes (and Strobe for that matter), in the <1 kHz range. I am disappointed to see the resurgence of visible PWM on some lights recently, and recommend manufacturers try to bump it up to the non-visible range (i.e., >3 kHz).

Initial max output is typically not as high as competing lights in the various battery classes that the SD10 supports – and the SD10 has a more significant step-down than most other lights.

The button switch on the original model suffered from a lack of tactile feedback – this has been corrected on the new version, which has a proper click. However, the interface is unusual as you need to press-and-hold to turn on or off (with a click to change modes). Also, there is a green LED under the switch which glows when you press it, but doesn’t seem to be used as low-voltage indicator.

Due to the electronic switch, there is a standby drain when not in use. While not unreasonable at 0.25/0.26mA, you may want to lock-out the light at the tailcap when not in use.

Overall build quality – while still acceptable – is lower than some competing products. I would consider the overall build to be a high-end budget light. That said, the bundled 3xAA battery carrier is of a very basic budget style.

Ideally designed for 1×32650 cells (which are uncommon), the light may seem slightly oversized for every other possible supported battery configuration.

The light can roll easily.

Preliminary Observations

The SD10 supports a wide range of batteries, making it a real “switch hitter” in its field. Physically, the SD10 combines support for D-cell width batteries and 3.7V Li-ion 18650/26650/32650 length cells. The circuit extends the range of support to include 3xAA in series (with the included carrier). You could see why on spec this would garner a lot of interest.

Of course, there are bound to be some wrinkles in the road. First off, you can’t expect the same kind of output on a single 1.5V D-cell alkaline as a 3.7V 32650. Basically, in terms of D-cells, you can think of this as a very fat 1xAA light that runs for a lot longer (thanks to the higher storage capacity of the large D cell).

And for that matter, 32650 (and appropriately-sized chargers) are relative rare. So despite being designed to support a wide range cells, you are practically limited to 3xAA or 1×26650 for most general users – and are therefore left with a somewhat bulkier light than necessary for this purpose (i.e. there’s wasted space inside the body this way).

Based on the specs, it would seem that Lumintop made the unusual choice of treating 3xAA and 1×3.7V Li-ion differently (with the lower voltage 3.7V Li-ion cells having higher output). Note however that my testing reveals that there isn’t actually much of a difference between these two battery sources, with actual max output somewhere in the middle of the reported specs. This puts the SD10 at the lower end of max outputs for recent lights in these two battery classes – but it’s still a good amount of light in practice.

The user interface is serviceable, with strobe “hidden” under a double-click as I prefer (note there is no mode memory for strobe – only the constant output modes). It’s a bit odd to have to press-and-hold for on and off, but I suppose you can get used to that. I am not surprised that there isn’t a low voltage battery indicator (i.e., given the wide range of cells supported, that would exceedingly difficult to program). So I don’t know why they bothered with a LED under the switch (i.e., it only shows when pressed, which is by definition blocked by your finger). At least with the revised switch on the new model there is proper tactile feedback now.

The SD10 has a decent beam, with good throw and spill – about what you would expect for the size. The new OP reflector helps smooth out the beam, and removes all the minor rings seen on the smooth reflector version. I am personally glad to see they have introduced a Neutral white tint option – especially in a U2 output bin and 3C tint bin (which is one of my preferred tints).

As an aside, by using a standard 40mm diameter head, you’ll find there are plenty of diffuser options out there that will fit on the light.

Performance-wise, I am personally disappointed to see visible PWM on the Lo/Med modes. The frequency is close to 1kHz though, so this may not be an issue for you if you aren’t particularly sensitive to it. Overall efficiency is fairly good, but the SD10 does tend to trail behind the popular current-controlled lights in the respective battery classes.

This has been a long review, given the update the SD10 line (i.e., the Neutral white mode with the textured reflector and improved electronic click switch). The SD10 is certainly versatile with its wide battery support – but as a result, the design of the light is probably not optimized to how you are likely to use it. So unless you actually need the battery versatility offered here, you might also want to consider one of the more dedicated offerings specifically tailored to your preferred use.


SD10 was provided by Lumintop for review.

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