Acebeam UC3A Signal Flashlight Review

The Acebeam UC3A Signal flashlight has two Luminus SST-36F emitters and a side lantern-style white and RGB output. It runs a 10440 or AAA cell! Read on!

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Official Specs and Features

Here’s a referral link to the Acebeam UC3A Signal flashlight product page.

Versions

There’s just one version, but it’s available in three body colors: orange, black, and olive green.

Price

The Acebeam UC3A Signal flashlight is available now for $34.90.

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What’s Included

• Acebeam UC3A Signal flashlight
• 10440 cell
• Charging cable
• Spare o-rings (2)
• Split ring and clip
• Manual, etc.

Package and Manual

Build Quality and Disassembly

Size and Comps

Length: 71.5mm/2.82″
Width: 31.05mm/1.22″
Height: 15.5mm/0.61″
Weight: 63g/2.22oz (incl. battery)

Here’s the light in hand:

Here’s the test light with the venerable Convoy S2+. This is a brass version, which is a good bit heavier than aluminum, but has the same dimensions: 24mm in diameter by 117.5mm in length.

Also in the photo above, my Standard Reference Material (SRM) flashlight is the Hanko Machine Works Trident, an 18350 light. While I have not reviewed or tested the Gunner Grip version seen here, I have tested a Hanko Machine Works Trident Total Tesseract in brass. I love the Trident, and it’s a striking contrast to the inexpensive Convoy S2+, another great SRM.

Retention and Carry

The Acebeam UC3A Signal flashlight has a pocket clip attached by two screws.

There’s a lanyard hole.

A lanyard isn’t included, but this split ring and clip are.

A magnet in the tailcap keeps the Acebeam UC3A Signal flashlight secure.

Above, you may note a new holder for my magnetic-tailcap items. That’s the Exceed Designs Hyzer Titanium Mini Hatchet D2 axe. The handle (as the name suggests) is titanium. But the blade is D2 steel and perfect for retaining magnetic tailcap flashlights! The Hyzer is available in a bunch of cerakote body colors as well as different-thickness D2 heads.

Power and Runtime

The Acebeam UC3A Signal flashlight runs an included, standard  10440 cell.

It can also run a single AAA. Either goes into the light with the positive end toward the head.

A printed label on the side indicates this, too.

The temperature lines in these charts are included as general context, not precise measurements. The values represent the range (min to max) during testing, but should not be taken as exact readings. A temperature sensor is not always attached to the bezel (or even the hottest spot, assuming that could be defined). Even with ideal placement, too many variables affect temperature to definitively state a specific max value.

Charging

The Acebeam UC3A Signal flashlight itself doesn’t have charging, but the included cell does. It’s a USB-C charging port.

A USB to USB-C cable is included.

Modes and Currents

Mode	Mode Claimed Output (lm)	Claimed Runtime	Measured Lumens
High	900-400-90	15s+14m+26m	725 (0s) 317 (30s)
Med	210-30	30m+1h	173 (0s) 172 (30s)
Low	80	1h50m	67
Ultra Low	4	23h	2.7
Side white High	35	3h	–
Side white Low	2	23h	–

Pulse Width Modulation

None of the modes use PWM. The first four are the front, and the last two are the white modes of the side lantern.

Click here to see a “baseline” – a chart with almost no light hitting the sensor.

Then there’s the Ultrafire WF-602C flashlight, which has some of the worst PWM I’ve seen. It’s so bad that I used a post about it to explain PWM! Here are multiple timescales (10ms, 5ms, 2ms, 1ms, 0.5ms, 0.2ms) to make comparing this “worst” PWM light to the test light easier. That post also explains why I didn’t test the WF-602C at the usual 50us scale.

User Interface and Operation

The Acebeam UC3A Signal flashlight has two e-switches. One (the “front” one) is for controlling the white front LEDs. The other controls all the side options.

Both switches are good-not-great. They have a sort of dead feel in the middle. They work just fine, though.

Here’s a user interface table!

State	Action	Result
Off (Or side on)	Click Main	Front on (Med)
Off (Or side on)	Hold Main	Front on (Ultra low)
Off (Or side on)	Hold Main (extended)	Front on (Ultra low) then Lockout (indicated by a few blinks of front)
Lockout	Click either	Side lantern blinks red/green
Lockout	Hold Main (extended)	Unlock to Ultra low
Front on	Hold Main	Mode advance (LMH only)
Any	Double click Main	Front High
Any	Triple click Main	Strobe
Off (Or front on)	Click RGB	Side white high
Off (Or front on)	Hold RGB	Side white low
Off (Or front on)	Double press RGB	Advance side solid colors: White, Red, Red flash, Green, Green flash, Blue, Blue flash, Red-Blue flash, Rainbow flow, White
Side On	Long press RGB	Change brightness level of side RGB

LED and Beam

The emitters are Luminus SST-36F and they each have a fully separate TIR. These two front emitters always work in unison; there are no modes that separate these two.

The side emitters are unstated, but there’s white and a rainbow of RGB colors.

LED Color Report (CRI and CCT)

[working on this data]

CCT (Correlated Color Temperature) refers to the measurement of the color appearance of light, expressed in Kelvins (K), which indicates whether the light is warm (yellowish) or cool (bluish). A lower CCT (below 3000K) is considered warm light, while a higher CCT (above 5000K) gives cooler, bluish light.

CRI (Color Rendering Index) is a measure of how accurately a light source renders colors in comparison to natural sunlight. Scored on a scale from 0 to 100, higher CRI values indicate that colors appear more true to life and vibrant, similar to how they would look under the sun.

Beamshots

These beamshots always have the following settings:  f8, ISO100, 0.3s shutter, and manual 5000K exposure. These photos are taken at floor level, and the beam hits the ceiling around 9 feet away. The far right two images are the white lantern – they don’t even show up on the ceiling

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

I keep the test flashlight on the left and the BLF-348 reference flashlight on the right. These photos are taken around 18 inches from the door.

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

Summary and Conclusion

The Acebeam UC3A Signal flashlight is a neat little light and very well built. I love that it supports the included 10440 cell as well as an AAA option. The user interface is easy enough to grasp, and I appreciate that the two buttons completely separate the emitters. The RGB options are neat, but I particularly like the white lantern. For around $35, this is a fun little light!

The Big Table

Acebeam UC3A Signal flashlight
Emitter:	Luminus SST-36F (2 emitters)
Price in USD at publication time:	$34.90
Cell:	1×10440
Runtime Graphs
LVP?	Yes
Switch Type:	E-Switch
Quiescent Current (mA):	?
On-Board Charging?	Yes
Charge Port Type:	USB-C (on cell)
Charge Graph
Power off Charge Port	–
Claimed Lumens (lm)	900
Measured Lumens (at 30s)	317 (35.2% of claim)^
Candela per Lumen
Claimed Throw (m)	85
Candela (Calculated) in cd (at 30s)	65lux @ 4.72m = 1448cd
Throw (Calculated) (m)	76.1 (89.5% of claim)^
Claimed CCT	–
Measured CCT Range (K)
Item provided for review by:	Acebean
All my Acebeam reviews!

^ Measurement disclaimer:  Testing flashlights is my hobby. I use hobbyist-level equipment for testing, including some I made myself. Try not to get buried in the details of manufacturer specifications versus measurements recorded here; A certain amount of difference (say, 10 or 15%) is perfectly reasonable.

What I like

• Orange body!
• Can run AAA cell
• Charging is on-cell, so no worry about charging AAA in this light
• Two switches completely separate RGB/Side from front output
• Reasonable cost

What I don’t like

• The switches aren’t great
• Pocket clip seems like a bolted-on afterthought

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Notes

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