Hello
Olight SR52 is a new compact thrower in Olight’s search and rescue series flashlights.
55mm diameter aluminum smooth reflector. 3x18650 batteries in parallel.
Built in charging circuit. 3 modes. Driver with excellent fast response. Quick start without any delay.
Great features for a great flashlight.
Read the review below for more info.
Olight SR52 comes in the typical for Olight transparent,plastic box.
The light can be seen before opening the package.
The most important information is written outside,on the package itself.
Beautiful,clean profile.Nothing superfluous.You can see the big side switch and the charging port.
Hard anodized aluminum body.Matte black finish. Excellent anodizing.
Great machine work.There are no sharp edges.
Deep cooling fins for good heat dissipating.
Very good anti-roll design.
Technical information taken from the user manual.
Stable,comfortable grip.The big ON/OFF side switch is very comfortable for use.
Not too heavy(for 3x18650 flashlight). The simple knurling is quite enough for a good grip.
Look at the end of this review for size comparing picture with other flashlights.
With the SR52 come also-Nice long lanyard,2 spare O-rings, Wall adapter(5V,1A output),Micro USB cable(1 meter length),
user manual,warranty card. Everything placed in this black box.
The Olight SR52 has built-in charger with Micro USB connector.
This means,can be charged very easy almost everywhere.
From a wall charger or from a car adapter(12V to 5V).
Can be charged also from a computer USB 3 port which supports 1A current(this is the max charging current).
Very good quality holster.Good protection for the flashlight.
Thin material,but well made and quite good for basic carrying.
No velcro tape on the back. Still two options for attaching-one plastic loop and a loop through double layer textile.
The SR52 fits excellent in the holster.
Beautiful profile.
The model name and serial number are engraved on the tail cap.
55 mm diameter reflector.
C shape blue sealing ring. Excellent protection for the glass lens-from impact or water.
The blue ring has GITD particles which illuminate for some time after the light is OFF.
Stainless steel bezel.
Perfectly clean and clear toughened ultra-clear glass lens with anti-reflective coating.
Aluminum smooth reflector-actually very slightly textured for a smoother beam.
Perfectly centered LED.
Close-ups on some details in the next pictures.
Precisely made cooling fins. The white dot is indicator light for charging status and low voltage warning.
Stainless steel bezel-black color coated.
Even closer look. 
This are the charging port cover and the indicator light.
The cover and the port base are made of plastic(not rubber). According to the user manual the flashlight is IPX8 rated.
The cover is well made. Hard to open accidentally.
The status/indicator light has two colors-Green and Red.
Red when charging. Green when charging is finished.
The indicator light will be red when the battery is depleted(when using the flashlight).
The side button is big,not too protruded,not hardly accessible recessed in the body.
Soft rubber boot with very nice feel.The switch is electronic type. The switch has click sound.
Can be activated only if pressed with a finger.
In my opinion,accidental activation is almost impossible. Even though the switch has electronic switch lock function.
As most side switches it’s not quite easy to find it in the dark and takes some time.
Overall, I found the switch comfortable and good in use.
The switch has the Olight’s logo.
The loop for lanyard attaching.
The SR52 uses 3x18650 or 6xCR123A batteries.
The batteries are connected in parallel. This is a great option when talking for “flexibility” of this flashlight.
The flashlight can be powered also with 1 or 2 batteries. The max current draw that I measured on High mode is ~3A.
This is not too much for a single battery. Just the run time will be shorter,the initial brightness will be lower and will decrease faster.
So,depending on the required run time 1,2 or 3 batteries can be used.
Closing the tail-cap with only one battery is harder because of the mechanical design and takes more time.
The charging current of the built in charger is 1A.
When charging 3 batteries the current to each of them will be 1/3 of 1A= 330mA.
I usually charge with Nitecore I4 charger and its charging current is 375mA when charging 4 batteries.
330mA gives quite good charging time for built in charger that is compatible with USB 3.
Because the batteries are connected in parallel, I tested what will happen if only one battery is in the flashlight when charging.
And yes the battery takes the whole 1A current.(I tested it just for a minute,because I can measure it only with the tail cap removed).
I didn’t charge one or two batteries fully and can’t say for sure that is a good idea charging less than 3 batteries in terms of charging algorithm,etc.
Charging stops at 4,19V which is just the right number for secure charging.
Fully charging 3x18650 batteries from 2.9V to 4.2V takes 11h 30min.
No battery carrier. Just insert the batteries in the body and you are ready to go.
High capacity protected batteries fit great in width and length.
Gold plated springs.The whole part with the springs is rotatable.
The front has mechanical reverse polarity protection.
Only button top batteries can be used.
Standard for Olight rectangular cut threads. Excellent machining.
This is the look which shows you that the SR52 is a serious thrower.(the picture below)
Cree XM-L2 LED.
Toughened ultra clear glass lens with anti-reflective coating.
UI
The flashlight is designed for quick and easy operating.Three constant modes and one flashing(Strobe). Low(100Lm)-Medium(600)-High(1200Lm) Strobe 1200Lm
Short press for ON/OFF.
Press and hold to change a mode or to cycle through them Low-Mid-High-Low-Mid…
Quick double press from OFF or ON activates ‘nasty’ Strobe.
There is a memory mode for the 3 constant light modes.
The memory works great as works in all other Olight flashlights.
Turning ON and OFF is quick,without delay.
There is a locking function for the switch.
Press and hold for about 2 seconds from OFF will lock the switch.
To unlock it,press and hold for a second.
No ultra Low mode. Since the flashlight is meant for a long distance search and rescue illuminating,the 100 lumen Low mode should be enough in most cases.
The SR52 uses an electronic switch (without physically disconnecting the power) and this requires some small current in Off mode.
Here the current is just about 2,5 uA. Really small,compared to other flashlights.
Thanks to the 3x18650 configuration,the SR52 has impressive run time performance. 4,5 hours with 3400mAh batteries.
There is no step down. The flashlight will run on max brightness as long as the batteries hold it.
Run time graph
With red color is an experimental run with only one battery. The form of the graph is typical for a light with no step down(and Panasonic core battery).
Lumen measurements
Olight SR52
High 1170 Lm
Mid 550 Lm
Low 92 Lm
ThruNite Catapult V5 1470 Lm
Fenix TK51 1810 Lm
The light is clean white. Cool white,but there’s no greenish or bluish tint.
Good angle of the beam.
The transition from hotspot to spill is not quite smooth,but this is normal for a thrower flashlight with well focused beam.
1200 Lumens max brightness.
84,100 cd peak beam intensity.
Beam shots
1meter , 1/20sec
(UF C8 dedome XM-L 3.15A) (UF C8 dedome XP-G2 1.75A)
1meter, 1/250sec
5meters, 1/6sec
5meters, 1/50sec
5meters, 1/100sec
Outdoor Beam shots
Olight SR52 Low-Mid-High
distance>50m
distance>50m
distance>50m
distance ~40m
The other flashlights used for comparison.
ThruNite TN32,ThruNite Catapult V5 NW,Fenix TK51 and the reviewed Olight SR52
In the end I have nothing bad to say about Olight SR52. Everything works as promised(at least in the review period).
The switch could be more protrude,but this will make it easier to activate accidentally.
A good choice for a long distance light. Thrower shape beam,extremely bright for a single LED flashlight.
Excellent build quality. High efficient driver.
Clean external design.A flashlight easy to carry and use.
The built in charger is just a great option.
Charging stops at 4,19V which is just excellent for 4,2V batteries.
Thanks for reading!
The SR52 was provided by Olight for test and review.
