Klarus A2 Pro Zoomable Flashlight Review

Klarus A2 Pro Zoomable Flashlight Review

Klarus has released the A2 Pro, a Zoomable flashlight! This light features high throw with good output as well as USB-C charging. Read on!


Official Specs and Features

Here’s a link to the Klarus A2 Pro Zoomable flashlight product page.

Versions

Looks like there’s only one version of the Klarus A2 Pro Zoomable flashlight.

Price

The current price (which is a sale price) for the Klarus A2 Pro Zoomable flashlight is $49.50. MSRP is a good bit higher, at around $70.


Short Review

This is a fairly typical zoomable flashlight that happens to be made by Klarus. The build quality is reasonable at the sale price, and if you really need a zoomable flashlight you could do much worse! I can not appreciate the 10,000 Kelvin and higher output, and I think anyone who uses this light (enthusiast or not) will notice how blue the output is. I would like for C to C charging to work, but A to C works well too.

Long Review

The Big Table

Klarus A2 Pro Zoomable flashlight
Emitter: Flood (Cold White)
Price in USD at publication time: $49.50
Cell: 1×21700
High Runtime Graph Medium Runtime Graph
LVP? Switch Warning
Switch Type: E-Switch
Quiescent Current (mA): 0.01
On-Board Charging? Yes
Charge Port Type: USB-C
Charge Graph
Power off Charge Port No modes in any condition
Claimed Lumens (lm) 1450
Measured Lumens (at 30s) 1187 (81.9% of claim)^
Candela per Lumen 1.6
Claimed CCT
Measured CCT Range (K) 11000-13000 Kelvin
Item provided for review by: Klarus
All my Klarus reviews!
Klarus A2 Pro Zoomable flashlight
Emitter: Throw (Cold White)
Candela per Lumen 23.2
Claimed Throw (m) 420
Candela (Calculated) in cd (at 30s) 639lux @ 6.112m = 23871cd
Throw (Calculated) (m) 309.0 (73.6% of claim)^
All my Klarus reviews!

^ Measurement disclaimer:  I am an amateur flashlight reviewer.  I don’t have $10,000 or even $1,000 worth of testing equipment.  I test output and such in PVC tubes!!  Please consider claims within 10% of what I measure to be perfectly reasonable (accurate, even).

What’s Included

Klarus A2 Pro Zoomable flashlight what's included

  • Klarus A2 Pro Zoomable flashlight
  • Klarus 4000mAh 21700 button top
  • 18650 adapter
  • AAA adapter
  • Charging cable (USB to USB-C)
  • Spare o-ring
  • Lanyard
  • Manual

Package and Manual

Klarus A2 Pro Zoomable flashlight box

Klarus A2 Pro Zoomable flashlight manual Klarus A2 Pro Zoomable flashlight manual

Build Quality and Disassembly

Klarus A2 Pro Zoomable flashlight

Klarus A2 Pro Zoomable flashlight tailcap

The tailcap has a nice long spring. Threads are also long, but of good quality. They’re anodized, square cut, and appropriately lubed.

Klarus A2 Pro Zoomable flashlight tailcap off

There’s a spring on the head end, too.

Klarus A2 Pro Zoomable flashlight head and tail spring

Size and Comps

160.1mm x 35mm x 27mm, and 140g without the cell.

If the flashlight will headstand, I’ll show it here (usually the third photo).  If the flashlight will tailstand, I’ll show that here, too (usually the fourth photo).

Klarus A2 Pro Zoomable flashlight in hand

Here’s the test light with the venerable Convoy S2+.  Mine’s a custom “baked” edition Nichia 219b triple.  A very nice 18650 light.

And here’s the light beside my custom engraved TorchLAB BOSS 35, an 18350 light.  I reviewed the aluminum version of that light in both 35 and 70 formats.

Klarus A2 Pro Zoomable flashlight beside torchlab boss 35

Retention and Carry

Only a lanyard is included for carry. This lanyard attaches through a single hole in the tailcap.

Klarus A2 Pro Zoomable flashlight tailcap lanyard installed

Since it’s a single hole and not a double, tailstanding is a bit uneven when the lanyard is installed.

Klarus A2 Pro Zoomable flashlight tailcap lanyard installed

There’s no pouch or anything else included for carry.

Power and Runtime

Included with the Klarus A2 Pro Zoomable flashlight is a 4000mAh 21700 button top. There are a couple of other options, which you can view below. The long plastic sleeve is for running a 18650 cell. The other is for running three AAA cells.

Klarus A2 Pro Zoomable flashlight possible power sources

The highest claimed output is with a 21700 cell, and so I tested with just the included cell.

Klarus A2 Pro Zoomable flashlight included 21700 cell

The cell goes into the Klarus A2 Pro Zoomable flashlight in the usual way – positive end (button) toward the head.

Klarus A2 Pro Zoomable flashlight included 21700 cell installed Klarus A2 Pro Zoomable flashlight AA cell holder

Here are a couple of runtime tests. The output steps down pretty quickly on High and then slopes off as the cell voltage drifts downward. While low voltage protection was not observed, both tests were stopped at (coincidentally) 2.52V. A switch warning was present, so I think this could be a form of low voltage protection – Klarus claims the working voltage as 2.5V-5V.

The switch indicates approximate cell capacity for 5 seconds after turn on, as follows:

Green: 30%-100% capacity
Red: 10%-30% capacity
Red flashing: <10% capacity

The manual is a little vague about this but it seems that if the capacity is below 30%, the switch indicator will stay on (and not turn off after 5 seconds.)

Charging

Charging is by way of a USB-C charge port in the head.

A USB to USB-C cable is included.

Klarus A2 Pro Zoomable flashlight charging cable

C to C charging does not work, but A to C charging happens at around 2A and is plenty quick, at around 3 hours.

During charge, the switch indicates in red. When charging is complete, the switch turns green.

As far as I can see, the manual does not state that you should absolutely not charge the AAA cells in the A2 Pro.

You should absolutely not use the charging function while AAA cells are installed!

Modes and Currents

Mode Mode Claimed Output (lm) Claimed Runtime Measured Lumens Tailcap Amps @4.2V
High 1450 (website claim)
1000 (manual claim)
5.5h 1187 4.90
Medium 400 13.7h 579 1.61
Low 50 110h 0.47

Pulse Width Modulation

Every mode uses PWM. It’s fairly fast, and you’re unlikely to notice it. PWM isn’t unusual (particularly on this class of light) but PWM this fast is a welcome improvement over the expectation.

For reference, here’s a baseline shot, with all the room lights off and almost nothing hitting the sensor.  Also, here’s the light with the worst PWM I could find.  I’m adding multiple timescales, so it’ll be easier to compare to the test light.  Unfortunately, the PWM on this light is so bad that it doesn’t even work with my normal scale, with is 50 microseconds (50us).  10ms5ms2ms1ms0.5ms0.2ms.  In a display faster than 0.2ms or so, the on/off cycle is more than one screen, so it’d just (very incorrectly) look like a flat line.  I wrote more about this Ultrafire WF-602C flashlight and explained a little about PWM too.

User Interface and Operation

Klarus uses a single indicating e-switch on the A2 Pro Zoomable flashlight.

Klarus A2 Pro Zoomable flashlight e-switch

Klarus A2 Pro Zoomable flashlight e-switch profile

The action is fairly low and quick.

The switch can indicate in green (as seen below) or red.

Klarus A2 Pro Zoomable flashlight e-switch actuation indicating in green

Here’s a UI table!

State Action Result
Off Click On (Mode memory)^
On Click Mode advance (High Medium Low direction)
On Hold Off
Any Double Click Strobe^^
Strobe Click Off

^ The manual states that the light will always come on in High
^^ Strobe isn’t mentioned in the manual

There is no electronic lockout. Klarus recommends loosening the tailcap a bit to lock out the light. The quiescent current is very low, in any case.

LED and Beam

Klarus does not state what emitter is in this zoomable flashlight.

Klarus A2 Pro Zoomable flashlight emitter

The bezel has a shape that will allow light to escape when headstanding.

Klarus A2 Pro Zoomable flashlight bezel

Below you can see flood (first) then throw. This is a zoomable light, and you can move fluidly between flood and throw while the light is on. Zooming the light is mechanical and not related to the electronic operation of the light.

Klarus A2 Pro Zoomable flashlight flood output Klarus A2 Pro Zoomable flashlight zoom output

LED Color Report (CRI and CCT)

You might have seen the photos above and wondered if the white balance was off. No, it wasn’t. The light is actually as blue as it looks above – it’s over 10,000K and higher on higher modes! This is not at all ideal.

Beamshots

These beamshots are always with the following settings:  f8, ISO100, 0.3s shutter, and manual 5000K exposure.

Tint vs BLF-348 (KillzoneFlashlights.com 219b version) (affiliate link)

I keep the test flashlight on the left, and the BLF-348 reference flashlight on the right.

I compare everything to the KillzoneFlashlights.com 219b BLF-348 because it’s inexpensive and has the best tint!

Conclusion

What I like

  • Build quality is acceptable at the sale price
  • Zoomable feature works fine
  • At full zoom, the emitter is blurred just enough that it’s not a projection of the emitter surface
  • Complete package
  • Multiple power options

What I don’t like

  • 13000 Kelvin on High
  • C to C charging does not work
  • Manual is inaccurate and incomplete

Notes

  • This content originally appeared at zeroair.org.  Please visit there for the best experience!
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