Acebeam H50 Headlamp Review

Acebeam H50 Headlamp Review

Acebeam has dropped the H50 Headlamp. It’s a three-emitter 18650 light with USB-C charging. Read on for more thoughts and testing!

Official Specs and Features

Here’s a referral link to the Acebeam H50 Headlamp product page.


There’s only one body but there are three emitter choices available.

3 x Samsung LH351D LED (Seen here)
3 x Osram KW CSLNM1.TG LED
3 x Nichia 219C CRI≥90 LED


The going price for the H50 is $89.90.

Short Review

This is a nice little light.  There are so many modes that it’s unlikely you’ll be unable to find the desired output.  But that’s at the expense of a UI that requires navigation and memorization to get to that mode.  And the switch is a little hard to press.

Still, the output is spectacular, and the emitter options are nice.

Long Review

The Big Table

Acebeam H50 Headlamp
Emitter: Samsung LH351D (6500K)
Price in USD at publication time: $89.90 at
Cell: 1×18650
Turbo (3 emitters) Runtime High (3 emitters) Runtime
LVP? Yes
Switch Type: E-Switch
Quiescent Current (A): 0.00003
On-Board Charging? Yes
Power off Charge Port with no Cell? All modes, with or without cell
Claimed Lumens (lm) 2000
Measured Lumens (at 30s) 1992 (99.6% of claim)^
Claimed Throw (m) 137
Candela (Calculated) in cd (at 30s) 297lux @ 4.83m = 6929cd
Throw (Calculated) (m) 166.5 (121.5% of claim)^
All my Acebeam 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

  • Acebeam H50 Headlamp
  • Charge cable (USB to USB-C)
  • Spare o-rings (2)
  • Headband
  • Manual and paperwork

Most of the accessories are in the box seen above.

Package and Manual

Acebeam ships in some very nice packages.  And the back of the box has quite a bit of information.

The manual is complete and has info for all the emitter options.

Build Quality and Disassembly

The H50 is possibly a bit unusual for an 18650 headlamp.  The emitters are in the center of the body, along the cylinder of the cell.  It’s a good, very balanced design, and the light as a whole is very well built.  Also symmetrical, which is something I like and appreciate.

Both of the ends unscrew.  And they’re both labeled too – you’ll need to put them back on their proper end.

The threads are big and beefy, and very smooth.  They have just enough lube.  The non-charge end has a big thick spring, too.  Both ends have an o-ring.

The positive terminal inside the body also has a spring, which is great for impact during use.

The tailcaps look exactly the same and they even have the same threading.  However they are not swappable:  One of the tailcaps will not make electrical contact with the wrong end, and so will not work.

As you can see below, the end with charging has much longer threads.

Also, the end with charging has a tailcap with no spring.  (Seen below are the parts that don’t go together.)

The charge port is well hidden under the threads.

There looks to be some slop in the cell when an unprotected 18650 is used, but there’s really not.  The cell fits in the tube just right.

Size and Comps

;83mm long, 26mm in diameter (tube only), and 62g in weight.

This probably isn’t a light you’ll use off the headband, but as far as 18650 lights go, this one’s not all that big.

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.  To be honest, barely bigger than the 18350 TorchLAB BOSS.  (!!!)

Retention and Carry

The main carry will of course be the headband.  There aren’t any other options – no magnet, no pouch, no pocket clip etc.  Just (and understandably) the headband.

This band alone weighs 44g.

It’s a solid headband and the light fits into it very comfortably.  The silicone arms allow rotation but also keep the light in place.  And it’s easy to get the light in and out.

The headband is quite branded.

It also has some grippy strips, to keep it from slipping around on your head.

It’s possible to completely remove the top strap.  Both ends of it have a “quick connect” de-strap area as seen on the “M” in the logo below.  So they can be cleanly removed.

Power and Runtime

A single 18650 powers this light.  It’s also possible to use 2x CR123.

The positive terminal of the cell goes into the H50.

There are so many modes on this light… I threw in a bonus runtime.  I picked the three highest current modes – two from a “three emitter on” group, and one from a “two emitter on” group.  So here’s the highest output:

Output is respectably steady at ~2000 lumens for around 2 minutes, then drops dramatically.  The light does have LVP, too.

And here’s the second runtime.  Sorry, the temp shut off during this test, but still captures most of the important part.

As for the two emitter output, here’s Turbo.  (Note that it’s a little higher than High of 3 emitter output – more on that in a bit.)

Runtimes look good.  Output is certainly good with these LH351D emitters.


The H50 also has built-in charging, by means of a USB-C connection on the tailcap.  The tailcap must be removed fully in order to access this port.

The necessary cable is included.  USB to USB-C, not USB-C to USB-C.

Charging is high for an 18650 – you’ll likely want to pick a good 18650 that can handle being charged at 1.7ish amps.

While charging is happening, the end of the light (not the indicating switch!) indicates completion.  During charging, the indication is red.  When charging is complete, the indication is green.

Modes and Currents

Mode Mode Claimed Output (lm) Claimed Runtime Measured Lumens Tailcap Amps
Turbo (3 emitters) 2000 2h15m 1992 4.80
High (3 emitters) 1000 2h30m 1063 2.41
Mid (3 emitters) 450 3h 408 0.77
Low (3 emitters) 55 3h30m 33 0.13
Ultra-Low (3 emitters) 10 16d 1.4 0.04
Turbo (2 emitters) 1350 2h15m 1326 3.25
High (2 emitters) 700 2h30m 656 1.72
Mid (2 emitters) 300 4h30m 281 0.63
Low (2 emitters) 40 5h15m 25 0.10
Ultra-Low (2 emitters) 5 21d 0.77 0.04
Turbo (1 emitter) 650 3h 612 1.60
High (1 emitter) 350 4h45m 340 0.84
Mid (1 emitter) 150 9h 145 0.36
Low (1 emitter) 20 10h30m 14 0.06
Ultra-Low (1 emitter) 3 30d 0.6 0.03

Pulse Width Modulation

All modes but Turbo (of each emitter setup) have PWM.  It’s very fast PWM though, and not something I can detect by eye.  Acebeam’s product literature say clearly: “Highly efficient constant current circuit design (Non-PWM).”  This is clearly not true.

One emitter on:

Two emitters on:

Three emitters on:

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

There is a single switch on the H50.  It’s an indicating e-switch and can be on top or bottom when wearing the light.  Logos matching common sense, it’s a “top” switch.

The switch is my biggest gripe with the light. …. really the only gripe, since the second one hinges on that gripe.  It’s hard to press.  It requires a bunch of force, and is recessed a bit, and just in general is not a pleasure to use.  I really have to aim to hit it, and I have to hit it straight down too.  No side or angle activation.  Now, that could be ideal for you – I do not think you’ll ever once accidentally activate the light – but for me, it’s not ideal.  Particularly because switching between 1, 2, and 3 emitters requires a double click.  So you really need to be perfect twice to get a good double click.  Or more if you’re going from 1 to 3 emitters, for example.  Couple that with the UI itself – by which I mean the modes go [all 5 single emitters] double click [all 5 two emitters] double click [all 5 three emitters] and you end up with modes that seem quite out of order.

Better in my opinion would be to just mimic a ramping UI and switch seamlessly between 1, 2, and 3 emitters, but always keep the output increasing.  That might put the emitters all out of order, but as a user what do I care about that?  I’m not picking a mode because it has 2 emitters on or 3 emitters on, I’m picking a mode because it has the output I need.

Here’s a UI table!

State Action Result
Off Click On (Mode and Emitter memory)
Off Hold Ultra-Low (Emitter memory)
Off Long Hold (3s) Lockout (3 flashes to indicate)
Lockout Long Hold (3s) Unlock (3 flashes to indicate, then Low with emitter memory)
Any Click then Click/Hold SOS
On Double Click Emitter Advance (1>2>3>1)
On Click Off
On Hold Mode advance (Low > Mid > High > Turbo) (No Ultra-Low)

LED and Beam

The emitters here, and there are three, are Samsung LH351D.  This isn’t a standard “triple” but there are three and they’re behind optics.  There are two other choices, mentioned above, and all three have their merits.  The Osram for example will likely throw better.  The Nichia are touted for their higher CRI.  And the 6500K Samsungs have a higher output than the other two.  No, it’s not possible to mix the three and have the best of all three worlds.

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

One emitter:

Two emitters:

Three emitters:

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

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


What I like

  • Very solid light
  • Meets specification on output, and 2000 lumens is quite good
  • Emitter options for exactly what your needs are
  • USB-C Charging is quite fast at ~1.7A
  • Headband is comfortable

What I don’t like

  • Hard to press switch coupled with an improvable UI


  • This light was provided by Acebeam for review. I was not paid to write this review.
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1 thought on “Acebeam H50 Headlamp Review”

  1. Lesley van Almkerk

    The runtimes seem strange to me. They claim a runtime of just 3H 30 minutes for 55 lumens, while most 18650 powered lights run for around 25-30 hours at 50 lumens. Any reason why this might be the case, cause at the same time the claim 9 hours for 150 lumens, which is in line with most 18650 powered headlamps.

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