Acebeam H16 Gray


Brand/model Acebeam H16 Gray
LED Cool White
Maximum lumens 1,000 lm
Maximum beam intensity 2,756 cd
Maximum throw 105 m
Battery 1*AA, 1*14500 Li-ion
Onboard charging Yes (USB-C battery)
Material Aluminium
Modes 3
Blinkies -
Reflector Smooth
Waterproof IP68
Review date April 2023


Acebeam reached out to see if I would like to review the Acebeam H16 Gray headlamp.

The Acebeam H16 Gray headlamp has a Cool White emitter. It is also available in a Black version with a high CRI Nichia 519A emitter.

Acebeam provided this headlamp for review for free. I have not been paid for this review nor have I held back my opinions of this torch.


The H16 Gray came in a small white retail box with a picture of the headlamp on the front.

Acebeam H16 Gray packaging front Acebeam H16 Gray packaging back

The following was included in the box:

  • Acebeam H16 Gray.
  • Headband.
  • Acebeam ARC14500 920mAh USB-C rechargeable battery.
  • USB-A to USB-C cable.
  • Two spare o-rings.
  • User manual.

Acebeam H16 Gray packaging 3 Acebeam H16 Gray accessories

Acebeam H16 Gray user manual

Torch in use

The Acebeam H16 headlamp is relatively small and fits comfortably on my head with a single strap.

Acebeam H16 Gray cover

There is magnet in the tailcap.

The headlamp can tailstand and it comes with a pocket clip.

Build quality

The Acebeam H16 has gray anodised aluminium. The quality is excellent like the Acebeam Pokelit AA Gray.

Acebeam H16 Gray front Acebeam H16 Gray left

Acebeam H16 Gray back Acebeam H16 Gray back

The pocket clip can be reversed for a deep carry.

The button feels soft.

Acebeam H16 Gray closeup button

Threads came lightly lubricated and the tailcap turns smoothly.

Acebeam H16 Gray closeup threads

The lens came with a protective film that needed to be removed.

Acebeam H16 Gray closeup protect

I snapped the red loctite on the threads near the head using vice grip locking pliers to take a look at the driver. The driver is held in place by the tube.

Acebeam H16 Gray teardown-1

Threads near the head are not anodised.

There is physical reverse polarity protection on the driver for the battery.

Acebeam H16 Gray teardown-4

There is thermal paste behind the MCPCB. The head of the torch has a few notches to help the MCPCB sit in place like a puzzle piece.

Acebeam H16 Gray teardown-3

The magnet is strong but I noticed that it rattles in the tailcap when the battery has been removed.

Acebeam H16 Gray closeup tailcap Acebeam H16 Gray closeup spring

The Acebeam branded headband is comfortable to wear. It is stretchy and there is a rubber strip on the inside of the headband to help stop the headband from sliding around the forehead.

Acebeam H16 Gray headband

Branding on the headband is reflective.

The headband has a rubber holder with three holes. An overhead strap was not included for the third hole. The headlamp is pretty sturdy so it may not need an overhead strap.

Inserting the headlamp into the rubber holder requires a bit of effort and the pocket clip needs to be removed first. Some other headbands use a hard plastic mount and allow pocket clips to remain on a headlamp.

LED, bezel, lens, reflector and beam

The H16 Gray comes with a Cool White emitter and has a smooth reflector.

Acebeam H16 Gray side

The bezel can be removed with snap ring pliers to get access to the reflector. The reflector dropped out and there is a gasket around the emitter.

Acebeam H16 Gray teardown 2

CCT, CRI, and duv

I have taken Correlated Colour Temperature (CCT) and Colour Rendering Index (CRI, RA of R1-R8) measurements with the headlamp positioned one metre away from an Opple Light Master Pro III (G3).

The CCT is around 5345K. The CRI is around 65.

The Delta u, v is slightly positive (green).

The beam has a relatively narrow white hotspot with a hint of green. It looks like a moon. The spill has a hint of purple on the High mode.

Cell Mode CCT (K) CRI (Ra) x y Duv
14500 Ultra-Low 5145 65.9 0.3428 0.3765 0.0129
14500 Low 5308 64.0 0.3378 0.3712 0.0125
14500 Med 5375 65.0 0.3359 0.3669 0.0112
14500 High 5428 65.6 0.3344 0.3639 0.0104
14500 Turbo 5471 66.2 0.3332 0.3613 0.0097

Calculate Duv from CIE 1931 xy coordinates

Dimensions and size comparison


I took the following measurements using a vernier caliper.

Measurement Unit (mm)
Length 81.4
Head length 20.4
Head width 19.2
Head diagonal 23.1
Bezel inside diameter 12.55
Pocket clip diameter 16.3
Tube diameter 17.0
Tailcap diameter 18.8


I took the following measurements using a digital scale.

Weight Unit (g)
Headlamp 26.58
Headband 26.07
Pocket clip 6.48
Battery 20.69
Headlamp, headband, battery 73.34

Size comparison with its competition

From left to right: Acebeam H16 Gray, ZebraLight H502pr

Acebeam H16 Gray, ZebraLight H502pr

From left to right: Acebeam H16 Gray, ZebraLight H502pr

Acebeam H16 Gray, ZebraLight H502pr

User interface

The headlamp has an electronic switch. You can double click to turn on, hold to cycle (Low, Med, High) while on, and single click to turn off.

State Action Result
Off Hold Ultra-Low
Off Two clicks On (mode memory)
Off Three clicks SOS
On Click Off
On Two clicks Turbo
On Hold Cycle (Low, Med, High)

Low voltage protection

I tested low voltage protection by connecting the driver of the torch to a bench power supply and then by lowering the voltage from 4.2V to 0V for a 14500 Li-ion cell, and from 1.5V to 0V for a Ni-MH cell.

There is low voltage protection for a Li-ion cell. The emitter flashed at 2.88V, turned off at 2.68V and the current stopped.

There is low voltage protection for a Ni-MH cell. The emitter flashed at 0.77V, turned off at 0.60V and the current stopped.


I did not notice any visible PWM (flickering).

What I like about the UI

  • Simple to use.

What could be improved

  • I personally prefer a single click for on and off.
  • Direct access to Turbo from off would be nice.

Batteries and charging


The included Acebeam ARC14500 920mAh 3.7V Li-ion cell arrived with a voltage of 3.736V. It came with a bit of plastic at the end to prevent accidental activation while in transit.

Acebeam H16 Gray battery

The code “23-M3” is on the wrap.

This particular cell is like the previous ARC14500-920 cells where there is an opaque insulation ring near the positive end to diffuse the light from the red and green charging indicator.


Power supply: PinePower Desktop USB-C
USB Meter: AVHzY CT-3 (recommended by LiquidRetro)
Room temperature: 16 C

Acebeam H16 Gray charging profile

I charged the battery from 3.14V to 4.183V for almost two hours at 5V 0.5A. The indicator light went from red to green when charging finished.

Acebeam H16 Gray charging red Acebeam H16 Gray charging green

Power supply compatibility

I tried the following power supplies with the built-in USB-C charger in the battery:

Power supply USB Type Protocol Does it charge?
Apple 61W Power Adapter USB-C PD Yes
Google Pixel Power Adapter USB-C PD Yes
PinePower Desktop USB-C PD Yes
PinePower Desktop USB-A QC Yes
PinePower Desktop USB-A Yes

USB-C to USB-C charging works.


Specifications from the manual:

Li-ion Battery (Acebeam ARC14500 920mAh)

FL1 STANDARD Turbo High Med Low Ultra-Low
Output (lumens) 1,000 + 310 310 130 30 5
Runtime 45s + 1h 45min 2h 8h 16h 58h
Beam Distance (metres) 105
Beam Intensity (cd) 2,756

Lumen measurements

I used a bench power supply to measure the current at turn on.

Cell Mode Amps at start Specs Lumens @turn on Lumens @30 sec Lumens @10 min
Ni-MH Ultra-Low 3.5 mA
Ni-MH Low 4.6 mA
Ni-MH Med 0.03 A
Ni-MH High 0.29 A 50 48 46
Ni-MH Turbo 2.19 A 235 234 46
14500 Ultra-Low 0.01 A 5 6 6 6
14500 Low 0.06 A 30 23 23 24
14500 Med 0.33 A 130 120 117 106
14500 High 0.63 A 310 292 280 261
14500 Turbo 2.89 A 1,000 913 797 252

Standby drain

5 µA

Runtime graphs

I used my own DIY lumen tube with a TSL2591 sensor and forked bmengineer’s project RuTiTe to record runtimes.

Note: Lumen measurements may be off by 10% with my DIY lumen tube.

The room temperature was approximately 16 C.

Acebeam H16 Gray 14500 runtime graph

Acebeam H16 Gray 14500 first 2 hours runtime graph

Acebeam H16 Gray 14500 first 10 minutes runtime graph

Acebeam H16 Gray nimh runtime graph

Acebeam H16 Gray nimh first 10 minutes runtime graph


Here is a summary of the runtime results:

Cell Mode User manual Runtime result Final voltage
Ni-MH Turbo 7h 40min 36s+
Ni-MH High 7h 50min 49s+
14500 Turbo 45s + 1h 45min 1h 47min 12s+ 3.14
14500 High 2h 1h 50min 26s+ 3.10
14500 Med 8h 8h 59min 44s+ 2.79
14500 Low 16h 17h+ 3.63
14500 Ultra-Low 58h 10min+

The runtime result is the time until my lumen tube no longer detects more than 1 lumen.

Low with a 14500 cell was at 5 lumens after 17 hours. I only tested Low for 17 hours and I found that it was still on after almost 21 hours.

I have put “+” to indicate that the headlamp remained on after Turbo, High and Med finished with a 14500 cell. Light output dropped below 1 lumen.

I have not measured the runtime for Ultra-Low, Low and Medium with a Ni-MH cell. The output is low and I suspect that the runtime may last longer than a day.

Overall, my runtime results lined up with the official specifications.


I took lux measurements with a UNI-T UT383BT at 30 seconds. Ultra-Low and Low were measured at one metre. Med, High and Turbo were measured at five metres.

Cell Mode Specs (cd) Specs (m) Candela measured (cd) Distance (m)
14500 Ultra-Low 18 8
14500 Low 74 17
14500 Med 300 34
14500 High 950 61
14500 Turbo 2,756 105 2,775 105


I went to a local park and aimed the Acebeam H16 Gray at a tree 70 metres away while using Turbo.

Beamshots were taken using a Sony RX100M2 using 3.2", f3.2, ISO 100, 5000K WB.

Acebeam H16 Gray (Turbo)

Acebeam H16 Gray Turbo beamshot

Acebeam Pokelit AA Gray (High)

Acebeam Pokelit AA Gray High beamshot

Cyansky HS5R

Cyansky HS5R Turbo beamshot

Brinyte HL18 Noctua

Brinyte HL18 Noctua Turbo beamshot


The Acebeam H16 Gray is a nice little AA headlamp. The quality is on par with the Pokelit AA.

The beam is fairly narrow and it throws well. The Gray version is aiming for more lumens while the Black version may have a nicer high CRI beam.


  • Comfortable headband.
  • Excellent build quality.
  • Simple UI.
  • Lightweight.
  • Good runtime.
  • Battery with built-in USB-C charging.


  • UI. I prefer a single click to turn on and off.


The Acebeam H16 Gray is US$44.90 at the time of writing.

I suspect that will have more Acebeam products in stock soon. I received this review sample early.

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