Nicron B400 Flashlight Review

Nicron B400 Flashlight Review

While the Nicron B400 flashlight isn’t new (from this year) it’s still a relevant high-output flashlight.  Read on for a bit of testing!

Official Specs and Features

Here’s a link to the official Nicron B400 product page.

Versions of the Nicron B400 Flashlight

Only one version is available.

Nicron B400 Flashlight Price

It looks like the going price for the Nicron B400 flashlight is $268.89. The Nicron B400 Flashlight is available on aliexpress.

Short Review

The Nicron B400 flashlight is quite the light.  I would rate it as the best of the Nicrons flashlights I’ve tested.  Even the PWM is better here – despite using PWM, it’s faster and not noticeable.  Output is also very high!  Charging is quick, but I’d love to see the light updated to USB-C.

Long Review

The Big Table

Nicron B400 Flashlight
Emitter: Cree XP70B (N4)
Price in USD at publication time: $268.89
Cell: 4×18650 (or 2×18650!)
“Crazy High” Runtime Graph High Runtime Graph
LVP? Yes, with warning
Switch Type: E-Switch
Quiescent Current (mA):
On-Board Charging? Yes, 12V/2A barrel connector
Claimed Lumens (lm) 12000
Measured Lumens (at 30s) 9847 (82.1% of claim)^
Candela per Lumen 4.2
Claimed Throw (m) 346
Candela (Calculated) in cd (at 30s) 1475lux @ 5.853m = 50530cd
Throw (Calculated) (m) 449.6 (129.9% of claim)^
All my Nicron 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

Nicron B400 Flashlight what's included

  • Nicron B400 Flashlight
  • Nicron 3000mAh 18650×4
  • Wall wart to barrel connector charger
  • Cigarette adapter to barrel connector charger
  • Nylon pouch
  • Manual etc

Package and Manual

Nicron B400 Flashlight box Nicron B400 Flashlight box

Nicron B400 Flashlight manual Nicron B400 Flashlight manual

Build Quality and Disassembly

Nicron B400 Flashlight feature photo

Being the fifth (of 5) Nicrons that I’ve handled, I have a pretty good fix on how Nicron lights feel in hand.  And their build quality, and the like.  The Nicron B400 flashlight is on par with the two headlamps I tested – the H15 and H25.

There’s one little thing I don’t much care for though, and it’s very visible.  That’s the soft wrap around the grip area.  Sure it’s good for grip and does provide extra grip, but it’s also not completely secured to the metal body.  So without a firm grip in the first place, you may find that the body twists under the silicone grip for example when tightening the tailcap.

Nicron B400 Flashlight tailcap

The head has many cooling fins but they aren’t deep.  More on this later.

Nicron B400 Flashlight cooling fins

One interesting feature is this “F>E” display.  Unlike I’ve seen on other lights in the past (which only use “similar” displays, and not “the same” display), this one is actually useful.  It steps down at reasonable intervals, and not all at once toward the end.  Even for charging, it’s useful.

Nicron B400 Flashlight battery indicator

Nicron B400 Flashlight grip

The tailcap gets a bit of branding as if the model number is an afterthought.  All the same, I appreciate that the light isn’t covered with markings.

Nicron B400 Flashlight model

These threads are well (or “overly”) lubed, keeping the tailcap action fairly smooth.

Nicron B400 Flashlight tailcap

You can see a hint of it above, but better below.  There’s a peg in the tailcap which fits into the body in only one orientation.

Nicron B400 Flashlight insides

You can see the connection point on the body below.  At first, I had a bit of trouble connecting those, but I figured out “the way” and it was easy from then on.  Just start with the tailcap at 90 degrees to the body and line up the peg.  Then tip the tailcap over onto the body, and you’re good to go.

Nicron B400 Flashlight insides

You can also see the cell orientation sticker inside the body.  Each bay has a sticker.  More on that later.

Nicron B400 Flashlight insides

Overall I don’t care for this keyed tailcap setup.  There are cleverer ways to do this.

Size and Comps

Officially: 152mm x 64mm, and 426g without the cells.

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).

Nicron B400 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.

Nicron B400 Flashlight beside torchlab boss 35

It’s not really a small light but that’s really ok – the role it plays isn’t “small.”  It’s a high output flashlight.

Retention and Carry

Nicron includes a nylon pouch for carrying the Nicron B400 flashlight.  It’s a nice formed pouch.

Nicron B400 Flashlight in nylon pouch

The pouch is only for carry; the light can not be used while in the pouch.

Also on the B400 is a threaded ring, which fits 1/4″ tripod screws.

Nicron B400 Flashlight tripod hole

Finally, there’s a lanyard hole in the tailcap.  No lanyard is included, though.

Power and Runtime

Nicron includes with the B400 the required cells.  That is four 18650 cells.

Nicron B400 Flashlight included 18650 cells

The cells included are 3000mAh button tops.

Nicron B400 Flashlight included 18650 cells

These cells are installed in a two-up, two-down fashion.  If you guessed based on the tailcap that this is a 2S2P setup, you were right – the light runs at 8.4V.  My output tests were only with 4 cells, but I gave it a quick go with two cells just to see what happens…. As long as you keep the two in series (ie, one up one down in the right bay), it’ll work just fine!  I wouldn’t recommend that for the higher two modes though, because that’s quite a drain on just one set of cells.

Nicron B400 Flashlight included 18650 cells installed

One thing to note about these four cells….  When I got the light I just threw the cells into the light and threw them on the barrel connection charger.  Don’t do that.  First charge all four cells in your bay-style charger to be 100% certain that they’re balanced.  When I charged on my initial charge, the cells actually ended up not just imbalanced, but also very overcharged.  Based on my other testing with the light, I don’t think this is necessarily a fault of the light, but of imbalanced cells from the start.  So partly my fault for not checking the cells, partly the light should have picked up on it too.

Anyway, balance your cells first.  Always, and for any multi-cell (particularly series) light!

Nicron B400 Flashlight fuel gauge

As I said above, this little battery indicator is actually quite useful.

Nicron B400 Flashlight battery indicator

Based on testing with bench power, it indicates as follows.  And remember this is an 8.4V light, so each cell should be approximately half whatever is mentioned below.

8.4V: 5 bars
7.5V: 4 bars
7.2V: 3 bars
6.7V: 2 bars
6.2V: 1 bar
5.7V: Blinking bar

And in runtime testing, the light definitely shuts off.  Even at 5.7V for the series system, that’s 2.85V per cell, which is perfectly fine.

Here are a couple of runtimes.  Turbo is quite bright at around 10500 lumens initially and steps down after a couple of minutes.  Even that “couple of minutes” is great – no gaming the FL1 here.  After that, the output wanders just a bit but that’s also great – the output is wandering based on temperature, and the temperature is keeping around 50°C.  Now, remember what I said about the cooling fins not being extra deep?  If those cooling fins had a bit more surface area and could dissipate heat a bit better, we’d likely see better-sustained output for the “Crazy High” mode (not “Turbo!”).

Nicron B400 Flashlight runtime graph

On the second-highest mode, there’s a big stepdown, but we still see a temperature relate modulation around 2000 lumens.

Here’s the fourth-highest mode, which is the highest of the normal rotation.  Output is great here, and while it does drift downward over the course of 5 hours or so, you’d be unlikely to even notice that it was drifting.

Nicron B400 Flashlight runtime graph

All in all, this is pretty great performance.


On the Nicron B400 flashlight is charging, but it’s barrel connector charging.  A charge port is to the right of the switch, and has a nice press-in cover.  “Nice” = secure.  In fact after a test or two there was a nice “fwoomp” upon opening this charge port.

Two charge adapters are included.  One is a wall wart – 12V@2A.  The other is a cigarette adapter for car use.

I don’t have any good (aka “safe”) way to log barrel connector charging, but I did note that charging takes under 4h15m, and the cells terminated at around 4.19V each.  Upon dropping them in a bay charger, no extra energy was added to get them to 4.20V, so the charging is “good.”  Note again, that I balanced the cells before beginning my runtime tests, and you should too.  That doesn’t mean you should balance them before my charge cycles.  Just that upon receipt of the light, charge the cells once to ensure balance.  After that, you’re probably good to go.

Modes and Currents

Mode Mode Claimed Output (lm) Claimed Runtime Measured Lumens Tailcap Amps @ 8.4V
Crazy High 12000 2.5h 9847 15.40
Super High 6000 2.5h 5319 5.01
High 3000 4h 2771 2.32
Med 1000 7h 952 0.65
Low 500 14.5h 495 0.34
Lower 200 33h 223 0.16

Pulse Width Modulation

All but the highest mode uses PWM for output management.  Based on the PWM we’ve seen from [literally all] other Nicrons, I’ll call this PWM a win.  It’s fast enough that you’re very unlikely to notice it.

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

Nicron uses an e-switch for the B400.  It’s not just any e-switch though.  This e-switch has two-stage actuation much like Nitecore and some other brands are using.

Nicron B400 Flashlight e-switch

The action is very good and clean – there’s no confusion between each stage.

Here’s a UI table!

State Action Result
Off Half-press No action
Off Full press On – Mode memory^
On Half-press Mode advance “in the same grade”†
On Full press and hold Lower mode, then the “grade 2″†
On Full press Off
Any Half-press 1s Lower mode
Any Full press Med mode
Off Full press and hold 5s Lockout (technically mode memory, then Super High, then Lockout)
Lockout Any 3 blinks to indicate lockout
Lockout Full press 5s Unlock to low

^ Memory surprisingly includes all the highs and strobes…. all modes can be memorized
† The manual differentiates the “Lower, Low, Med, High” as “grade 1” and “grade 2” is “Super High, Crazy High, Strobe, SOS.”

LED and Beam

In the Nicron B400 Flashlight are four Cree XHP70B emitters.  XHP70B and XHP70.2 are the same (as far as I understand).

Nicron B400 Flashlight emitters

Nicron doesn’t make any CCT claims and based on the image above you might think this is a cool or very cool output light.  Read on!

Nicron B400 Flashlight reflectors

Each emitter has a small reflector, so while this light does have massive output, it also throws quite well too.

Nicron B400 Flashlight

The bezel allows light to escape while headstanding.

Nicron B400 Flashlight bezel Nicron B400 Flashlight

LED Color Report (CRI and CCT)

Like I said above, Nicron doesn’t make any CCT claims on this light, so here’s the actual reading.  Depending on the mode, we see from around 5700K to just over 6000K.  So “cool white” but not too bad.


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

Tint vs BLF-348 ( 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 219b BLF-348 because it’s inexpensive and has the best tint!

Conclusion on the Nicron B400 Flashlight

What I like

  • Good dual stage switch
  • Complete package with 3000mAh cells
  • Standard cells
  • Onboard charging is quick
  • High output with good throw
  • Access to Lower mode from any state!m

What I don’t like

  • In the 6000K range – a bit cool
  • Barrel connection charger (not USB-C)
  • Some parts of the user interface aren’t ideal


  • This light was provided by Nicron for review. I was not paid to write this review.
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