Acebeam PT40

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Acebeam PT40 review

Table of contents

Acebeam PT40 specifications

Brand/modelAcebeam PT40
LED6*Samsung LH351D 6000K
Lumens3,000 lm
Beam intensity3,680 cd
Battery config.1*18650
Review dateJanuary 2021


Not all flashlights are equal! Tell that to your partner, lol. If you’re into flashlights for a while, you might get stuck to a certain shape. Most of them look the same, and once in a while, you notice something different, or something special. And the Acebeam PT40 is one of those interesting new ideas. Not that this type of flashlight is new, but definitely in this size and shape. The Acebeam PT40 looks like the usual mechanic lights people use in car repair shops, but much smaller.

Package quality.

I didn’t get excited about the packaging, so let’s get into the more important stuff as quickly as possible.

  • The flashlight: Acebeam PT40
  • Pocket clip (attached)
  • Spare o-rings
  • Magnetic tailcap (pre-installed)
  • Headstrap
  • Some papers (manual, warranty card, a battery warning card)
  • Mine also included a 3100mAh battery (but this is not by default it seems)

Handling of the light

Yes, you can definitely wear this as a headlamp, and no that doesn’t look good, lol. And it also doesn’t feel very comfy. But I do understand it can be handy in a car repair shop, since you can work on something and do inspection with just 1 light.

The problem is however, it’s not easy to attach or remove from the headband. It’s definitely possible, but if it was meant to switch between handheld and headband, I would have come up with a different solution. Something like a plastic clip or hook, or magnet or something. It’s just a bit too uncomfortable to switch between handheld and headband use.

The switch is located on 1 end while the tailcap is located on the other. So even when the flashlight is attached to the headband, it’s pretty easy to replace batteries. It’s an electronic switch and a single click will turn it on. You can also lock it by pressing the switch for 4 seconds.

The pocket clip is attached to the body (towards the switch) with 2 little screws. It’s not very stiff, and rather easy to clip onto your belt or pocket. Oh, and before I forget, it does work standing up right (tail standing).

Build Quality, and Warranty

Acebeam has been in the flashlight industry for quite a few years. And their build quality is pretty good. The flashlight contains of 2 separable parts, but if you use some strength it turns into 3 parts. The battery tube is glued to the head with some threadlocker. But it’s easily removable.

The threads near the tailcap are anodized, so a quick turn and your flashlight is physically locked out, which is great. The threads on the head side are bare, which is great a well, because it wouldn’t interfere with loosening the tailcap.

The tailcap has a little spring and magnet installed. Unfortunately, the magnet isn’t very strong, and if you bump into the light while attached to something metal, it would easily fall down. Besides that, the magnetic tailcap can definitely help if you are working on a car! And on top of that, it is very easy to remove the magnet, without tools. You just press against the spring from one side and the spring can be removed. The magnet then falls out. Putting the spring is easy as well, and you don’t need any special tools.

The pocket clip is black, and looks okay. It doesn’t look very strong though.

In terms of anodization, this light is just like all other Acebeam flashlights, great.

Warranty: 5 years: the dealer will repair or replace the flashlight with the same or a similar model. After 5 years, you have to pay the cost of spare parts and shipping, no labor charge! Check the details here:

LED, Lens, Bezel, and Reflector

One thing I like about Acebeam, is the choice of emitters. Most larger companies don’t offer this, and you can’t choose the beam color (CCT). The PT40 comes with 3 emitter options:

  • 6* Samsung LH351D CRI90 6000K
  • 6* Luminus SST20 4000K CRI 95
  • 6* Nichia 219c CRI90

The one I’m reviewing is the Samsung LH351D with Hi CRI90. Although they are supposed to be 6000K it doesn’t look too bad at all. It kind of looks neutral white to me. This is also a kind of novelty, because a few years ago, it would be impossible to have Cool white and HI CRI >90 at the same time. Hi CRI was usually just for emitters below the 4000K temperature. Now, they are even available at 6000K and above.. quite amazing to me.

LEDs are behind TIR optics and are 6 in a row. This results in a very wide beam, which is of course the whole point of this flashlight. According to their specs it has a 110 degrees wide beam. Almost like a mule.

The ‘bezel’ is screwed with some mini torx (with pins inside) to make it more difficult to open.


  • Length: 126.85 mm / 4.99 ”
  • Head diameter: 22.61  mm / 0.89 ”
  • Bezel inside: 10mm / .398″


  • Empty: 92.5 g / 3.26 oz
  • With battery: 142.1 g / 5.01 oz

Right angle flashlights

Size compared to other right-angle flashlights. Since I only have 1 other, here we go:

left: Fireflies PL47 gen2, right: Acebeam PT40.

Driver & User Interface:

The Acebeam PT40 has 6 different output levels.

Available modes:

  • Ultra Low, Low, Mid 1, Mid 2, High, Turbo
  • SOS

From OFF:

  • Single-click: On (last used mode)
  • Double click: Turbo
  • Triple-click: SOS
  • Press and hold >1sec: Ultra low
  • Press and hold >3sec: Lockout mode

From ON:

  • Single-click:  turn Off
  • Double click: Turbo
  • Triple-click: SOS
  • Press and hold: Cycle through the menu from Low to High


  • To Turbo: double click from Off and On
  • To Ultra Low: press and hold 1 second from Off
  • To SOS: triple-click from Off or On

Mode memory:

  • Yes, it does

Blinky modes menu:

  • Only SOS, no Strobe.

Low battery warning:

  • The light starts blinking

Lock-out mode:

  • Press and hold the switch for more than 3 seconds from Off.


  • None visible

Other info:

Something strange happens when you shake the light violently. The light will shut off when you shake it in Ultra Low and Low and Mid1. In Mid2, High and Turbo that doesn’t happen.

Funnily enough, after doing some drop tests… this behavior stopped.. and worked without turning off.

Batteries & Charging

The flashlight doesn’t have a charging system built in, but the battery does. The battery arrived at 3.95V. It is the Acebeam ARC18650H-310A with a capacity of 3100mAh and a Micro USB port.

During charge, a little red glow is visible next to the positive button. And because of the charge current (0.75A) I would actually recommend having a special battery charger to charge the battery because 3100mAh at a speed of 0.75A = 4 hours, which is pretty long. The battery can be charged in most 18650 chargers although it’s a little longer than a normal 18650 battery.

It’s also interesting to note that the battery has a green LED continuously glowing, even when the USB cable is removed. This is normal! So if you wonder what is going on, the green LED doesn’t just show when the battery is fully charged, but it’s on even when the battery is not in use.


Lumen measurements:

All output numbers are relative for my home-made Integrating Sphere. It is set up with an Extech SDL400 Lux Meter for measurements including a Kenko PRO1D ND-16 filter. The base measurement is done with a Convoy S2+ that has been tested at 255 lumens.

All of my readings were taken from a fully-charged Acebeam 18650 3100mAh

Amps were measured with a Fluke 77III, at startup, at the tailcap.

Parasitic drain: 30 µA

Ultra Low0.03 A151212
Low0.15 A807474
Mid10.43 A220220222
Mid 21.24 A580576578
High2.71 A110011111124
Turbo5.71 A3000 lm2853 lm3082 lm

As you can see, the measurements were pretty close to the specifications. But Turbo was starting off just above specs, but they should be measured after 30 sec.. and then my measurements were at 2853 lumens.


The runtime test was done with the 50cm integrating sphere, including the Kenko Pro1D ND-16 filter and Extech SDL400 data logging Lux Meter.

It’s hard to see how the runtimes are for the first few minutes or few hours, so the next graph shows just the first 2.5 hours

Turbo drops to roughly 750 lumens at 2.5 minutes, and continues for almost 1.5 hours when the flashlights drops even more and within a few minutes it turns off. At this point you will have seen many Low Voltage Warning.. the flashlight starts to flicker.

High starts a bit above 1100 lumens and does that for about 12 minutes when it drops to roughly 690 lumens. It does that for about 1 hour and 40 minutes. At that point the Low Voltage Warning has been blinking fos several minutes.

  • Mid 2 has a runtime of about 2 hours and 16 minutes.
  • Mid 1 has a runtime of about 6 hours and 8 minutes
  • Low has a runtime of about 18 hours straight.

I didn’t do the Ultra Low runtime test which is supposed to go on for 80 hours.

Throw Measurement

Measurements were taken indoors at 5 meters with a professional Hagner E4-X Lux Meter.

ModeSpecsCandela measuredMetersYards
Turbo @ start7700175191.93
Turbo @ 30 sec3680 cd7250 cd170186.24

As you can see, the light performs much better in terms of throw than advertised.


For the following beamshots I used a Canon EOS 5D Mk2 and a 50mm lens. manual settings: ISO1600, 1/4sec , F4, 5000K

The shed is about 65 meters / 71 yards away. 

Disclaimer: This flashlight was sent to me for review at no cost by Acebeam. I have not been paid to review, nor have I been holding back on problems or defects.

Final Verdict


  1. High quality work light
  2. Plenty bright, especially for close up work
  3. Beam is very wide
  4. Includes a removable magnet in the tailcap
  5. Includes a headband
  6. HIGH CRI, even with cool CCT


  1. On the fly changing from headband to handheld is not easy
  2. Magnet is not very strong
Author: Marco

4.5 stars: ★★★★⋆

While our star rating provides a reliable indicator, we encourage you to read the full review to make an informed decision based on your own needs and preferences.

The Acebeam PT40 is my first ‘work light’ to review and I like it quite a bit. Having a very wide beam, enough runtime, and the ability to wear it as a headlamp is great. It even has Hi CRI at a color temperature of 6000K. The only few downsides make it .5 stars less. It would have been even better if you could easily switch between handheld and headband.

Acebeam PT40 for sale

Unfortunately, this is discontinued. Instead check out one of the following articles:

  1. Best buy guide: the best headlamp
  2. Overview page: Acebeam flashlight reviews

1lumen selects and reviews products personally. We may earn affiliate commissions through our links, which help support our testing.