Acebeam X45 review with measurements (4x XHP70, 4x 18650)

Disclaimer: The Acebeam X45 was provided for testing by the manufacturer at no charge.

With the X65 Acebeam showed that a world class thrower doesn’t have to have a pencil beam. The X45 is almost half the weight of the X65 and redefines the compact floody monster series with its 16500 lumens of claimed output. Decent throw comes as a side effect of the massive output.

Features and manufacturer’s specifications
Battery: 4x18650, the light comes bundled with four 3100 mAh high drain batteries
LED: 4x Cree XHP70 P2, choice of 5000 K and 6500 K
Waterproof: IPX8, 2 meters
Mode memory: yes (low, mid, high)

Manufacturer’s output specs
Maximum output: 16500 lumens
Other output levels: 9000/4000/1500/500/3 lumens
Light intensity: 85200 candela
Beam distance: 583 m

Measured dimensions and weight
Length: 155 mm
Head width: 88.5 mm
Handle width: 50.5 mm
Weight: 523 g for the light and 192 g for the batteries

User interface
From off:
Click side switch to turn on the light on the last mode used (low, mid, high)
Double click for turbo, two additional fast clicks for turbo max (light turns off between clicks)
Triple click for strobe
Long press for firefly mode
Even longer press for lockout mode or unlock, light flashes twice to verify lockout mode

From on:
Click to turn off
Hold switch to advance to the next mode (low-mid-high-low…)
Double click for turbo, two additional fast clicks for turbo max (light turns off between clicks)
Triple click for strobe

The turbo max is not very easy to activate since the timing has to be precise on the second double click. Click once and wait for the light to turn off and then immediately click again. Normal fast double clicking works only for turbo.

Box and contents

There’s no check boxes on my review sample, but according to the measurements I have to assume it is the 5000 K neutral white one.

Bundled in the box:
4x 18650 3100 mAh batteries, protected high drain IMR
2 Spare o-rings
User manual
Warranty card

There’s a thread inside the bezel for accessories such as a diffuser and colored filters.

Acebeam stayed with the original XHP70 on the X45 even though the new and improved XHP70.2 is already available. No donut holes visible though, but they might have been able to squeeze out a bit more juice at lower temperatures from the new one.

The light consists of three removable parts: the head with the LEDs and electronics and the handle in which the battery carrier slides into.

The battery fit is very tight.

The handle doesn’t contain any electronics, it’s just a dumb (and light) aluminum shell.


The bundled 3100 mAh 18650 batteries are very good in their current capability (low internal resistance similar to Sony VTC6). They are quite long and only barely fit to the X45 battery carrier, but the contact is excellent.

The carrier sets the batteries in series so protected batteries are recommended. Flat top batteries can also be used though, thanks to the springs+buttons in the carrier. The battery carriers in the X45 and K60/K70 are interchangeable.

The carrier connects to the driver board from either end, it doesn’t matter which way it is inserted to the handle. The center pin is positive, the outer ring negative.

Acebeam 3100 mAh 18650 IMR measurements
Length: 69.9 mm
Width: 18.7 mm
Weight: 48 g
Protected: yes
Capacity: 2935-2966 mAh
Energy: 10.559-10.751 Wh
Average voltage: 3.593-3.600 V
Internal resistance: 0.036 ohm
Over current protection: >20 A (my load only goes up to 20 amps)
Low voltage protection: 2.49 V

Capacity was measured at 1 amp down to 2.5 volts after being charged to 4.20 volts at 1 amps.

Judging from the measurements, I’m assuming the batteries are Sony VTC6 with an added protection circuit and Acebeam wrappers.

Size comparison

The Acebeam X45 isn’t a soda can light even though the configuration is similar to other multiemitter lights. It is both longer and wider in the head than the Olight X7 and MecArmy PT60. While the latter ones do fit in your jacket pocket, it’s quite a reach with the X45. Even so it is still quite a bit more compact than the single XHP70 Acebeam K60.

Beamshot comparisons

Wide head and shallow reflectors make the X45 very floody. The hotspot is tighter than on the Olight X7 for example, but the spill is also wider. Overall beam tint is similar to the Olight with the green hotspot and cool blue spill. There’s just a lot more overall output and double the throw.

Links to individual images with some extra flashlights:
Acebeam X45
Olight X7
MecArmy PT60
Noctigon Meteor M43
Acebeam EC50 II NW
Nitecore EC4SW (used as the white balance reference for all beamshots)
Acebeam K60 modded with a sliced dome 4500 K CRI90 XHP70

Acebeam X45
Olight X7
MecArmy PT60
Noctigon Meteor M43
Acebeam EC50 II NW
Nitecore EC4SW
Acebeam K60 modded with a sliced dome 4500 K CRI90 XHP70

Acebeam X45
Olight X7
MecArmy PT60
Noctigon Meteor M43
Acebeam EC50 II NW
Acebeam K60 modded with a sliced dome 4500 K CRI90 XHP70

Acebeam X45
Olight X7
MecArmy PT60
Noctigon Meteor M43
Acebeam EC50 II NW
Acebeam K60 modded with a sliced dome 4500 K CRI90 XHP70

Beam, tint and color rendering

Just like in most XHP70 lights going for max output, the beam has a greenish tint in the hotspot and bluish in the spill combined with a low color rendering index. On lower modes the tint moves even more towards green. The emitters used in my sample of the X45 are the greenest I’ve seen yet. I would have gladly sacrificed some output to get a more neutral tint like in the Acebeam EC50 II NW. This is of course assuming that the emitters in my sample are indeed the 5000 K versions. At least the hotspot measured at 5000 K, but with Cree you never really know what you’ll be getting, so your mileage will vary.

Tint in different parts of the beam.

Tint in different brightness modes. The shift pretty much already reveals that no PWM is used on the higher modes, but since firely suddenly moves backwards, it is a clear indicator of what’s happening…

Spectral data and color rendering

For spectral information and CRI calculations I use an X-rite i1Pro spectrophotometer with HCFR, Babelcolor CT&A and ArgyllCMS spotread for the graphs and data. For runtime tests I use spotread with a custom script and an i1Display Pro because it doesn’t require calibration every 30 minutes like the i1Pro.

Explanation of abbreviations

CCT = correlated color temperature, higher temperature means cooler (bluish)
CRI (Ra) = color rendering index consisting of 8 different colors (R1-R8), max value 100
CRI (R9) = color rendering index with deep red, usually difficult for led based light sources, max value 100
TLCI = television lighting consistency index, max value 100
CQS (Qa) = Proposed replacement for CRI, RMS average of 15 color samples
CRI2012 (Ra,2012) = Another proposed replacement for CRI, consists of 17 color samples
MCRI = Color rendering index based on the memory of colors or 9 familiar objects
NEW Read more about the IES TM-30-15 method
TM-30 = The newest color rendering method using 99 samples. Preferred for comparing LEDs.
TM-30 (Rf) = Accuracy of colors, fidelity index. Replaces CRI (Ra).
TM-30 (Rg) = Gamut of colors, saturation index. Higher number means more saturated colors.
Tint dev. (“Duv” in the CTA screenshots) is the tint’s distance to the black body radiator line in the CIE graphs. The higher the number, the greener the tint. 0,0000 means absolutely neutral white and negative numbers mean rosy/magenta tint. Anything over 0,0100 can be described as visibly green.

If you have an hour to spare, I recommend watching this presentation on IES TM-30-15 which also shines light into color rendering in general.

Color rendering on turbo max.

Color rendering comparison.

Runtimes and output

The X45 absolutely trounces the smaller soda can monsters. When uncooled, it offers on average over 50 % more output than the MecArmy PT60 and Olight X7 during the first 5 minutes. This comes at a price though, since the flashlight gets very hot. I measured the head at 96 celsius and the handle at 73 celsius after 5 minutes. This isn’t good for the batteries so I recommend only using the turbo max momentarily and never without supervision.

The second highest turbo mode is closer to other lights in output, except that when sufficiently cooled, the output doesn’t step down at all before the batteries are getting low after 30 minutes. Half an hour at 8000 lumens is quite impressive.

On turbo, the temperature climbs up to 65 C in the head and 50 C in the handle after 5 minutes. After the stepdown at 8 minutes the readings are 73 C and 59 C respectively. This is too hot to hold, so the user will probably lower the output on their own before the light decides it’s too hot.

Cooling the light after it has already stepped down will not resume original turbo (max) output and requires the user to activate it themselves. On the other hand the turbo max mode works exceptionally well even when the cells are below 50 % charge. I measured only a slight difference in output compared fully charged cells at 50 % charge (14060 vs. 12950 lumens average during 3 minutes).

Turbo max works with lesser batteries too. Even the lowly Panasonic NCR18650B gets it up to 12400 lumens. And since the light doesn’t heat up quite so much due to the lower current, the stepdown happens a bit later than on higher current batteries.


No PWM on any mode, but there’s very low amplitude 600 Hz pulsing on firefly, that is impossible to see with the naked eye.


The Acebeam X45 will be a polarizing light for sure. On the other hand it is the most powerful flashlight I’ve ever tested, putting into shame other pocket sized monsters (I haven’t tested the Imalent DT70), but the light quality leaves a lot to be desired. I wished Acebeam offered the X45 as a more neutral version with passable color rendering and less green tint and shift. I know this is difficult to achieve with the emitter used, but they seemed to do quite well with the EC50 II. I for one would gladly have less output for better tint. As it is, the beam for me is too green in the hotspot and too blue in the spill.

On to the good then. The workmanship is excellent and the output is absolutely ridiculous. Yeah, it is a bit bigger than the soda can lights I’ve tested previously, but the overall amount of light and throw is in another class. The output stays constantly high on the high mode at over 4000 lumens. The insane mode (turbo max) the X45 doesn’t limit the output for you until it’s too late. If you feel like your hands are burning, just switch to a lower mode. It is probably intentionally made difficult to access to avoid accidents…

With some emitter mods, the Acebeam X45 will be one helluva thing. For the prize I would have wanted it to cater to the needs of enthusiasts who appreciate tint in addition to power though. I appreciate that Acebeam provided the light with some seriously high quality 18650 batteries that you can utilize in other high output lights as well.

+ Exceptional output for the size

  • Good mix of throw and flood
  • Good regulation on high and turbo
  • Comes with excellent high drain batteries
  • Turbo max mode works well even with almost drained batteries
  • Solid construction

- Strong green tint in the hotspot and blue tint in the spill

- Low color rendering index

- Turbo max mode still difficult to activate

- Thermal regulation doesn’t increase output after cooling

- Gets burning hot on turbo max unless cooled

  • Negative end marked with an orange stripe on the batteries

Thanks a lot maukka! Performance is indeed stunning. But the tint… dear lord the tint… My Led Lenser has got better tint than this. Neutral white in the centre and cool white in the spill or something… pfff…

These emitters have some serious identity crisis…

Great review as usual :+1: . What a nasty Tint…… Now I know why X45 got a nickname “Green Lantern” :confounded: .

I am fairly certain that the bundled batteries are Sony VTC6, since the internal resistance, capacity and discharge curves all match those perfectly. The batteries are also a very good match to each other.

Thanks for another excellent review, both manufacturer and users should be delighted with the kind and amount of information you provide! I enjoyed the read. :slight_smile:

Fantastic review - way to go the extra mile!

Wow!!, great light and great review. Thanks. _ b

Mine should be here in a few days. I did not see an option for tint when I preordered from HKE. To be honest idk which I’d prefer so I guess it’s good I don’t know what I’m getting because I’m bad at having buyers remorse. I’m sure I’ll love which ever one I get. I was really hoping it had slotted battery insertion instead of a carrier which reduces weight and makes it much easier to swap but aside from those 2 things I can’t wait to play with this thing.

Thanks for this info. Mine on order. Will have it in the first week of May. Will test it against the Imalent DT70.

Did test both of them. The Imalent does has a furher throw by at least 100 ANSI meters. The Acebeam X45 is the flood king between them.

Some more info regarding this review of the X45. According to Chris from this is the 6500K flashlight and not the 5000k. The 6500k flashlight using Cree XHP70 P2 1C LED with four cores. This LED has the problem that the lighting color shows a light green spot light according to the engineers of Acebeam. The 5000k version does not show the greenish color in the spot light.

Correction: Not PWM on firefly, just some very mild pulsing at 600 hertz in the output and impossible to see with a naked eye.

Excellent review. I’m wondering how the cool white version looks?

Great review with nice details !

In high mode - 4000lm is comfortable to hold in hand for extended period? Is the high mode safe to use unattended ? (to leave like a candle and drink beer )

I have the K60 and at 4000lm after 5 minutes is pretty hot (depending a lot of ambient temperature) , safe to use unattended on level 1700lm.

Excellent review, Thanks!

After getting a fast photosensor with 14 ns rise time (Thorlabs DET36A/M), I measured some switching noise on low and mid in addition to firefly. The frequency is so high that there’s no chance of ever seeing it, but maybe some serious slow motion cameras might be affected.

Low (109 kHz)

Mid (430 kHz)

The sensor reveals some other interesting output anomalies from various lights…

Interesting. Can you tell what fraction is the ripple compared to the total light output?

It can be visually approximated, since the center horizontal line is zero output.

May I know where is the regulations forbid to take a picture in such building? I’m living in CA as well!

Great review as usual!! Many thanks maukka :beer:

I have a little question: maybe have you done a measure of the intensity vs angle for this light?
Like you did with AB EC50 gen II , EC60 and Olight R50 ?

Haven’t done that unfortunately.

Well done for this review. Will you perhaps also do one on the up coming X80?