Olight S20R (XM-L2, 1x18650/2xCR123A) Rechargeable Dock Review: BEAMSHOTS, RUNTIMES+


May 27, 2006



Welcome to my Olight S20R review. :wave:

Olight has recently updated their popular Baton series of lights (S10/S15/S20) with a new rechargeable version (known by the "R" addition to the model name). These new "R" version lights are very similar to previous generation Baton lights, except they all come with an Olight-branded 3.7V Li-ion battery, and desktop USB-charging dock. :eek:oo:

Given the large number of comparisons required, I've decided to process these into three individual reviews for the S10R (for 1xCR123A/RCR), S15R (for 1x14500/AA/NiMH) and S20R (for 1x18650) separately. Note that the user interface and charging design are common to all three models, and will be repeated in each review.

Let's see how things shape up for the S20R, especially in comparison to the second edition S20-L2 (2013) that I reviewed previously. :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 Cool White
  • 1 x 2600mAh 3.7v 18650 rechargeable lithium battery
  • Output (ANSI)/Runtime: High: 550 Lumens/ 2 Hours, Medium: 120 Lumens/ 9 Hours, Low: 5 Lumens/ 120 Hours, Moonlight: 1 Lumen/ 480 Hours
  • Peak beam intensity: 3,500 cd
  • Max beam distance: 118 m
  • NEW Low-profile side switch featuring a battery power indicator, which glows red when battery runs low
  • NEW Includes patent-pending Micro-USB charging dock and a 2600mAh 18650 rechargeable battery
  • NEW Thermal management safety program provides overheating protection by dropping high output by 50% after 4.5 minutes of constant on.
  • NEW Glow-in-the-dark o-ring in bezel to help locate flashlight from accidentally dropping it
  • 99% light transmittance rate through tempered glass, with two-sided anti-reflective coating
  • Multi-function side switch with four brightness levels, plus a strobe mode
  • Automatically return to your last brightness level with the built in memory function
  • Removable two-position pocket clip
  • Flat tailcap with strong magnet, giving you the ability to use the light as a hands-free worklight
  • Highly reliable 6061-T6 aluminum alloy structure with ant-scratch, Type-III hard anodizing with a stainless steel bezel to protect against drops
  • Reverse polarity protection to prevent improper battery installation
  • Can be powered by two non-rechargeable CR123A lithium batteries as a last resort in an emergency.
  • Low standby current below 15uA
  • IPX-7 (waterproof up to 1m)
  • Impact resistant to 5 ft / 1.5m
  • Flashlight Body: 4.27 in/108.5mm x 0.91 in/23mm
  • Charging Dock: 2.17 in/55.1mm x 1.97 in/50mm x 0.63 in/16mm
  • Weight: 52g/1.83 oz (body, excluding batteries), 24g/ 0.85 oz (charging dock)
  • MSRP: ~$70



The packaging is similar to the 2013 edition S20, but includes the extra items described above. Inside the clear plastic container is the S20R (with Olight 18650 battery installed), extra o-rings, split ring, good quality wrist lanyard, product insert, manual, charging dock base, micro-USB cable for dock, adhesive gel-pad for dock, gel-pad installation manual. As before, there is also an overview of specs on the bottom and back of the packaging.


From left to right: Olight RCR (650mAh), S10R, Olight 14500 (750mAh), S15R; Olight 18650 (2600mAh), S20R.




From left to right: Olight 18650 (2600mAh), S20R; Skilhunt DS20; Olight S20-2013; Thrunite Neutron 2C 2014; Zebralight SC62, SC600-II; Eagletac D25LC2.

All dimensions directly measured, and given with no batteries installed:

Olight S20R: Weight: 52.2g (98.5g with Olight 18650 2600mAh), Length: 108.5mm, Width (bezel): 23.1mm
Olight S20 (2013, XM-L2): Weight: 52.4g, Length: 106.5mm, Width (bezel): 23.1mm

Eagletac D25LC2: Weight: 50.0g, Length: 116.3mm, Width (bezel): 22.5mm
Fenix PD35: Weight: 82.7g, Length: 138.1mm, Width (bezel): 25.4mm
Foursevens Quark Q123-2 X (Regular tailcap): Weight: 44.6g, Length: 112.7mm, Width (bezel) 22.0mm
Nitecore EC20: Weight: 77.1g, Length: 129.2mm, Width (bezel): 25.4mm
Nitecore P10: Weight 82.0g, Length: 135.1mm, Width (bezel): 25.5mm
Nitecore P12: Weight: 89.7g, Length: 139.4mm, Width (bezel): 25.4mm
Skilhunt DS20: Weight: 53.8g, Length: 110.0mm, Width (bezel): 24.0mm
Sunwayman C20C: Weight 57.6g, Length: 104.8mm. Width (bezel): 25.6mm
Thrunite TN12-2014: Weight: 80.0g, Length: 140.5mm, Width (bezel): 25.4mm
Zebralight SC62: Weight: 42.3g, Length: 96.5mm, Width (bezel): 23.2mm, Width (max) 26.1mm
Zebralight SC600: Weight 87.2g, Length: 107.8mm, Width (bezel) 29.7mm

Overall dimensions are similar to the S20-2013, except the S20R is slightly longer now (likely to accommodate the charging circuitry).





Physically, the new "R" editions of the Baton lights look generally similar to the 2013 editions of regular Baton family. These lights remain relatively petite for their respective classes. Lights come with black anodizing (matte finish) and bright white labels. Although still without typical knurling, the raised checkered patterns on the body help with grip. With the reversible pocket clip attached, I'd say grip is good. What has changed is the button and tailcap design, which I will get to in a moment.

The bi-directional pocket clip is comparable to the earlier models, no real change here. It seems to hold onto the light fairly securely. I personally like it, as you can clip it on you in either orientation (i.e., bezel-up or bezel-down carry), although it might be rough on clothing given how tightly it fits.

In the head, the S20-2013 (like the previous S20R) has a spring on the positive contact (so flat-top 18650 should also work just fine).

The R-series tailcaps have been re-designed with a new charging dock feature – but otherwise functions as before. The S20R uses the same square-cut screw threads as before, still anodized for tail lock-out. Light can tailstand, and there is a split-ring/lanyard attachment hole on the side of the tail cap as before. And the tailcap still has a strong magnet, to allow the light to stand horizontally off any vertical metal surface. That said, I don't find the magnet quite as powerful as before. This means you may not be able to get the S20R to hold as stably off a small piece of metal (like a screw head on plastic plate cover, for example). It also does not seem to be removable now, as it is integral to how the charger functions.

What is new on the tailcap are the two exposed metal areas – an outside ring, and a recessed inner circular contact. These connect magnetically to the charging dock. I am happy to report that there is no open voltage at the tailcap, so there is no risk of accidentally shorting the 18650 battery inside the light. Scroll down for discussions of the dock and charging process.

As with the earlier models, the S20R uses an electronic switch in the head for on/off and mode changing. The button design has updated though – the hard plastic switch is now slightly recessed behind a raised metal surround. This means that the risk of accidental activation is now greatly reduced. :thumbsup:

As with the S20-2013, there is still a low voltage warning sensor under the switch (visible through the clear pinhole opening in the middle). The red LED below the switch will light up and flash as the battery nears exhaustion.

The head of the light is relatively unchanged, with a flat stainless steel bezel ring as before. However, the standard red o-ring has been replaced with GITD blue one, and the S20R now uses the same smooth reflector as the S15 (was light orange peel on the S10/S20 2013). Note that early versions of the Batons had an excessive anti-glare coating on the lens that produced some green-tint shifting. This has been revised over time, and the current anti-glare coating doesn't produce any obvious issues.



The S20R uses the same XM-L2 Cool White emitter as the previous S20-2013. The emitter remains well centered on my samples. Please scroll down for beamshots.

Olight Battery




All the new R-version models come with an appropriately-sized Olight-branded battery (3.7V Li-ion). Rated capacity of the 18650 included with the S20R is 2600mAh. Scroll down for actual testing results.

Charging Dock









The new charging dock for the R-series lights has an interesting design. The desktop dock connects by a supplied micro-USB 2.0 cable for a standard USB port (no AC adapter supplied, but you can easily find an after-market one). Note that the charging docks are common for all three R-models, so all are limited to the standard 500mA max charge rate of USB 2.0. See a charging analysis later in this review.

The is an adhesive gel pad supplied with the dock, in case you want to semi-permanently mount the dock on your desk.

Charging contact is made through those two metal areas on the base of the light's tailcap. Thanks to the magnetic attraction, this firmly holds the light in place, and allows charging to commence. A similar magnetic mechanism is used on the Klarus lights, though without the flat desktop mount dock.

A LED on the dock lights up constant red during charging (slowly flashing red when no light is present, or if an error is detected). The dock is supposed to terminate the charge and go green once the battery is fully charged (~4.2V). In practice however, this initial batch of lights has an issue in fully charging the cells. On my S20R, the dock charging terminated and the indicator went green once the 18650 reached a resting voltage of ~4.14V. I understand from Olight that they plan to fix this on subsequent batches, to allow charging up to the typical ~4.2V.

Personally, this is not a big issue for me, as it is better to consistently under-charge Li-ion than over-charge (i.e., better for the health of your cells). And you can always take the cell out of the light and charge separately if you want.

The "Extended" USB port on the dock is a secondary output port. Basically, with the dock plugged into a power source, this provides a pass-through to charge other USB-based devices (e.g., cell phone, tablet, etc.), up to a reported 2A charging current. Of course, for that kind of charging, you are better off using an AC adapter for the input source, with good quality cables (i.e., I wouldn't want to to push a standard USB port too hard).

Scroll down for an overview of specifics of the charging process, along with other performance characteristics of the light.

User Interface

The R-series interface is unchanged from the 2013 models of the Baton series.

As before, a quick press and release (i.e., click) of the electronic switch turns the light on or off.

Mode switching is controlled by holding down the electronic switch. The light will cycle between Lo – Med – Hi, in repeating sequence. As before, simply release the switch to select your desired mode. The light has mode memory – if you turn it off/on, the light returns to your previous level.

The R-series lights continue to features the ultra-low "Moonlight" level. You access this mode directly from off by a sustained (>1 sec) press-and-hold of the switch from off. This is a nice feature, as it means you can always turn the light on in the lowest possible mode if you want (i.e., no matter where you memorized it before). Mode cycling and memory works as before, once on.

You can physically lock out the light by a twist of the tailcap, as before. The "soft lock-out" is similarly unchanged - hold the switch down from off for >2 secs, the light shuts itself off (i.e., after one second of the Moonlight mode). You will not be able to use the light until you unlock it (by pressing-and-holding the switch for >2secs again). Note that this means that if you want Moonlight, you must release the switch before the lock-out takes effect (hold the switch between 1 and 2 secs). To unlock, simply press and hold the switch for more than 1 sec now.

There is still a "hidden" strobe mode, accessed by double-clicking the switch when on. Double-click again to return to constant on (or turn off and on).

Note that there is an undocumented "short cut" to jump to Hi from off: simply double-click the switch from off.


For information on the new R-series lights, including the build, user interface and dock charging, please see my video overview of the recent models:

For 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.

As an aside, if you want to get an instant notification for every new review that I post, you can subscribe to my YouTube channel. The vids go public at the same time as the reviews here on CPF. :whistle:


As always, there is no sign of PWM at any output level – The R-series lights are current-controlled, just like their predecessors. :)

However, my S20R sample did show some mild circuit noise on the Med level, that wasn't present on any of the others:



The Med level signal was not visible in the beam in any way – I only show the oscilloscope traces above for the sake of completeness in the testing.


The S20R strobe is a fairly typical fast "tactical" strobe, of 9.7Hz frequency (as before).

Standby Drain

As the switch is an electronic one, a standby current drain is always present when a battery is installed.

I measured this standby drain at 22.6uA on my S20R (previously 27uA on my S20 2013, which was unchanged from the original S20). For the supplied 2600mAh 18650, that would translate into 13 years before a battery would be fully drained. Hardly a concern – although I do recommend you lock out the switch at the tailcap (or soft-lock out electronically) to prevent accidental activation.

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). There are many of these on the market now, and this model was favorably reviewed by HKJ here.

For charging tests, I started with a discharged Olight 18650 battery (tripped, so no resting voltage). 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 USB port).

Initial charging current and input voltage:



As you can see, charging started at 0.49A with a typical USB ~5V input voltage ("U" is meant to represent Volts on the top display above). This is fully consistent with the USB 2.0 specs.

For the first 3 hours of charging, this rate was unchanged.

By 3hr and 30 mins, charging was down to 0.42A.

By 4hrs, charging was down to 0.38A.

By 6 hrs, charging was down to 0.20A.

By 7hr and 30mins, charging had terminated (and the dock was showing green).

Note that the resting voltage of the 18650 battery was only ~4.14V at this point (as it was on all samples of my initial batch of R-series lights). Olight apparently plans to adjust this to the more typical ~4.2V full charge on later batches.

While the actual charging time is different for each member of this family (due to the varying battery capacities), all the Olight R-series lights seem to be using a good CC/CV algorithm. This pattern and time is quite reasonable for a 0.5A charger. :thumbsup:


For white-wall beamshots below, all lights are on Max output on an 3.7V Li-ion (18650) battery. 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.









Beam pattern remains very similar to the previous generation S20), as you would expect (i.e., the Batons are all relatively "floody").

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).


There isn't really any output difference between the new S20R and the previous generation S20 (2013).

To better illustrate that, here is a detailed output comparison on 1x18650.


No real difference. :)

Output/Runtime Graphs:

I previously used AW protected 2200mAh batteries in all my runtime tests, due to their ability to fit and work in every light – and their consistent capacity levels across samples and batches over time. After extensive testing, I have settled on a variety of brands of protected NCR18650A (3100mAh capacity) that show good correlations and internal consistency (and can work in various lights). As such, I will now start showing 3100mAh runtimes in my reviews. :wave:

Let's start with the AW 2200mAh cells, to compare back to the S20 2013:



And now some more recent comparisons, on 3100mAh cells:



As expected, the S20R performs identically to the S20 2013 on my AW 2200mAh cells. :) As before, there is a gradual step-down from max on Hi, taking about 4 mins to level off at the lower Hi level.

Also as expected, the supplied Olight 2600mAh 18650 has a longer runtime than my AW 2200mAh.

The 3100mAh results show that the S20R is quite competitive to other recent lights in this class – although of course, max output is typically a bit lower than most of the competition.

Let's see how the S20R performs on 2xCR123A, which is still supported:


Again, no difference to the previous S20-2013.

As before, on all batteries, overall efficiency is excellent at all output levels in the Baton series. :wave:

Potential Issues

All Baton lights use an electronic switch, and therefore require a small stand-by current when fully connected. However, the standby drain on S20R remains at an extremely low 22.6uA, which would theoretically translate into well over a decade before the supplied 18650 would be drained.

Accidental activation is always a potential concern with electronic switches – however the likelihood of this has been greatly reduced thanks to the new switch design. You can also "soft" lock out the switch electronically, and can still physically lock out the light at the tailcap as well.

The tailcap magnet is no longer removable (i.e., it is integral to how the charger functions), and it doesn't attract as heavily as before.

The supplied in-light charging feature on this initial batch of lights will only charge batteries to ~4.14V resting voltage. I understand Olight is looking to correct this on subsequent batches.

Preliminary Observations

The R-version update to the Olight Baton series offers a new functionality: in-light 3.7V Li-ion charging (with supplied Olight battery). Otherwise, general performance of the S20R remains largely unchanged from the most recent S20 (i.e., comparable beam patterns, output levels, runtimes, etc).

The only other notable difference is the revised electronic switch, which is recessed from before, with a built-up metal surround now. This means that accidental activation is far less likely - a significant improvement in my view. :) As before, there is a red LED below the switch that lights up to tell you when the battery is running low.

The build and overall feel of the light is similar to the earlier model (i.e., decent bi-directional clip, keychain attachment point, magnetic tailcap, etc.). The R-series lights are a tiny bit longer than before (likely to accommodate charging circuitry), and I find the magnet has slightly less pull (but still more than enough). There is no open voltage at the tailcap, as the magnetic connection is required for initiating charging. Unlike before, the magnet is no longer removable (i.e., it is integral to how the charger functions).

The beam pattern of the light hasn't changed much. The reflector has switched from the light orange peel (OP) texturing of the S20-2013 to the smooth version from the S15 line, but this doesn't have much impact on the beam. A new GITD blue o-ring has been added to all models. :)

The in-light charging feature uses a good CC/CV algorithm, and will safely charge your 18650 batteries inside the light. Since the S10R/S15R/S20R use a common dock (and common 0.5A max charging rate), it will take over 7 and half hours to charge the supplied 2600mAh 18650 battery. Also note that the initial batch of R-series lights/docks would only charge batteries to ~4.14V resting, but I understand Olight is working on raising this to a more typical ~4.2V. Performance of the supplied Olight-branded 18650 is excellent, consistent with the 2600mAh rating.

The charging dock is well designed, with a secondary output feature (i.e., you can charge your cell phone right from the dock). It even includes a gel pad to stick it to your desk. That said, a slightly longer input USB cable would have been nice (as well as an AC-adapter), but you can easily pick these up elsewhere.

Circuit function of the S20R is similar to before, with an identical user interface and set of output levels. Again, overall output/runtime efficiency is unchanged from before (and remains excellent). :thumbsup:

Basically, the S20R is the 2014 version of the S20-2013, with a switch improvement and the new functionality of in-light charging added. Unless you are trying to save a few bucks, there is no real advantage to getting the previous S20 – but by the same token, there is no probably need to "upgrade" to the S20R (unless you really want the in-light charging or recessed switch). And I expect the switch updates to migrate back to the regular S20 series in due course. Either way, the S20/S20R are certainly strong contenders in the petite 1x18650 class. :wave:


S20R was supplied by GoingGear.com for review, on behalf of Olight.


Aug 4, 2013
Valley Forge, Pa.
Thanks again for the review! Where the HE.. is RYP!!!

Do these reviews get redundant sometimes? Especially when the series like this are basically the same. You put a lot of time and effort into ALL of them.

I appreciate as I am sure others do as well.:D
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May 27, 2006
Where the HE.. is RYP!!!
Well, there's no new video for this one (since I used a common video for S10R/S15R/S20R), so there would have been no new notifications to subscribers of my YouTube feed. ;)

Do these reviews get redundant sometimes? Especially when the series like this are basically the same.
Yes, there is a lot of redundancy is the three reviews - but the alternative is to do one massive "family" review of all three models in one post. :sweat: I've done that on occasion, but find I find it unmanageable for lights where each one supports a wide range of battery types (i.e., you would have had ~20 runtime graphs). Add in all the beamshots, tables, etc, and it gets too hard for people to find what they are looking for in such a massive review.

This way, each review stands alone as a pretty good summary of each light, which is probably what people will be looking for. :wave:


Newly Enlightened
Mar 4, 2014
If anyone wonders what's inside S20R, here's what I found:

Note that the aluminum star in the picture is from S10. S20R had a same size copper star inside.