Reviewer's Note: This is a review of both the stock Nitecore Tube, and the custom modified version from Vinh Nguyen (V54). For more information on Vinh's lights, please check out his subforum of the CPF Custom Flashlight Builders and Modders forum, including his TubeVN discussion thread.
I've long thought that some sort of rechargeable keychain light would be a good idea, as most of the cheap ones with 2016/2032 lithium coin cells die a slow (or rapid) death from battery drain. As cheap keylights are commonly given out by many vendors when purchasing lights or batteries, I've literally collected buckets of these over the years.
Since I am curious about the (somewhat oddly named) Tube, I have purchased the full series of colors from an authorized Nitecore distributor. Vinh has kindly sent me his personal sample of the TubeVN to compare. As such, this review can serve as double-duty – a review of the stock Tube, as well as the V54 TubeVN. And since I actually have multiple samples of the stock light, we can also draw some preliminary conclusions about typical variation.
One point about the Vinh mod – note below that the TubeVN is on the left, stock Tube is on the right below (both clear versions):
There is no engraving on my sample of the TubeVN, so there are no obvious external signs to differentiate it to the stock Tube. I've attached the included keychain split rings on the stock sample, to help me tell them apart (although the difference becomes more obvious once your turn it on). But more on that in a moment …
Stock Nitecore Tube Reported Specifications:
(note: as always, these are simply what the manufacturer provides – scroll down to see my actual testing results).
- LED: (not specified)
- Output / Runtime: Max: 45 Lumens / 1 Hour - Min: 1 Lumen / 48 Hours
- 1 to 45 lumens infinitely variable brightness
- Peak Beam Intensity: 150cd
- Beam distance: 24m
- USB Rechargeable
- Integrated high efficient Li-ion rechargeable battery
- Intelligent protective circuit with over-discharge/over-charge/short-circuit protection and integrated blue power indicator (goes out automatically when charging is complete)
- Beam angle up to 100 degrees
- Constructed from extremely lightweight PC materials, Slim Compact Design
- Finger friendly user interface, with Side Switch Operation
- Available In 5 Stylish Colors
- Stainless steel key ring connector withstands 35kg weight
- 1.5 Meter Impact Resistant
- IP65 Waterproof
- Dimensions: Length: 2.22" (56.5mm) - Width: 0.83" (21mm) - Height: 0.31" (8mm)
- Weight: 0.34 oz (9.6g)
- NOTE: Micro-USB charging cable not included
- MSRP: ~$10
V54 TubeVN Reported Specifications: (where different from above)
Note: As always, these specs are simply what Nitecore and Vinh provide – scroll down to see my actual testing results.
- Current boosted
- $26.50 shipped USA
- +$5 for international shipping (up to 3)
- +$5 "V54" Engraving
Stock retail packaging is a simple card with specs/instructions printed on the front and back (random observation: they have actually prepared different cards for each color model). Included in the blister pack is the light with a small and large split-ring. Note that no micro-USB cable is included, so you have to get one of your own (common with many cell phones now).
There is no printed manual included, but you can download one from Nitecore's website. The specs on the packaging do explain most of what you need to know.
All dimensions directly measured, and given with no batteries installed (except for keychain lights, where they are integrated):
Nitecore Tube: Weight: 9.1g (without keychain rings), 11.4g (with both keychain rings), Length: 55.9mm, Width: 20.7mm (widest width) 9.2mm (widest depth)
Nitecore TubeVN: Weight: 9.1g (without keychain rings), Length: 55.9mm, Width: 20.7mm (widest width) 9.2mm (widest depth)
Titanium Innovations Keylight: Weight: 8.7g (with keychain rings), Length: 55.9mm, Width: 27.0mm (widest width) 9.3mm (widest depth)
Foursevens Preon P0: Weight 13.0g (with keychain clip), Length 55.0mm, Width 12.6mm (bezel)
Foursevens Preon P1: Weight 15.3g (with keychain clip), Length 75.6mm, Width 14.0mm (bezel)
L3 Illumination L08: Weight: 22.4g, Length: 77.8mm, Width (bezel): 17.0mm
Lumintop Tool AAA: Weight: 15.3g, Length 82.6mm, Width 14.4mm (bezel)
Olight i3 (2013/14): Weight 12.3g, Length: 69.3mm, Width (bezel): 14.0mm
Thrunite Ti3: Weight: 11.5g, Length: 69.9mm, Width (bezel): 13.6mm
Titanium Innovations Illuminati Aluminum: Weight 13.9g (with keychain clip), Length 68.8mm, Width 14.0mm (bezel)
There is no only obvious difference to the appearance of my TubeVN, so I've used a variety of the colors for the pics throughout this review.
The Tube lights have thin rectangular bodies, made of polycarbonate (held together by four small screws). There is some texturing/ridge detail on the body, which helps with grip. There are also the rubberized switch cover and micro-USB port cover (which thoughtfully stays attached to internal column at all times, so you won't lose it). There is a double metal keychain attachment point at the base of the light, and two sizes of stainless steel split rings are included.
The Tube lights come in 5 body colors – clear, black, pink, green and blue. These have varying opacities, which affect how the lights look when on. To illustrate this, below are the clear, black, pink and blue Tubes, followed by the clear TubeVN – first on Min, then on Max.
Note that the black one is very darkly colored, so relatively little light penetrates the body. Clear obviously lets the most light through, followed by pink and then blue above. The pink body tends to produce a fair amount of red/pink-tinged colored light in the vicinity of the body.
I find the green to be something of a lime color (not particular attractive in my view, but your tastes may vary). My stock green sample was defective and wouldn't activate when clicked/pressed. Instead, the white LED would flicker on/off when held in certain positions or moved around – making think there was some sort of short on the circuit board. So, I took the green unit apart:
I noticed one poor solder joint above (bottom right of the switch), but fixing it didn't help – this one sample (out of five purchased) remained DOA.
As an aside, this may be an argument for getting the TubeVN – at least you know Vinh would catch and fix anything like that.
One of the key features of the Tube is the built-in Li-ion battery, with standard micro-USB charging. Please note however, that you must supply your own cable. These are easily available online for a couple of bucks, but it means an extra purchase if you don't already have one from a cell phone, camera, etc.
There is a blue LED on the circuit board that illuminates when a USB cable is attached and charging is going on. Shown below for the clear and black versions.
Simply peel back the rubber plug covering the micro-USB port to plug in the cable (the plug remains attached). Once the light is fully charged, the blue LED shuts off. Scroll down for more discussion of the charging process.
The main white LED of is of unknown source, and is a (relatively) very high output 5mm type of cool white emitter. Truthfully, even in stock Tube form, I haven't seen one this bright before – it puts all other keychain squeeze lights I've handled to shame.
Scroll down for beamshots and direct output/throw measures.
To turn the light on in its lowest mode, simply click (press-release) the switch from off. To turn the light on in its highest mode, double-click the switch from off. Once on, a single click turns the light off.
From on, you can ramp the output from min-to-max in a continuously-variable fashion by pressing and holding the switch. In my testing, it takes 3.2 secs to ramp from min to max brightness. Unfortunately, there is no pause once max is reach – the ramp immediately starts over at min, in a continuous fashion. This means it is hard to choose the absolute max (unless you use the shortcut above from off).
There is a momentary max mode available from off – simply press-and-hold from off. The light turns off once you release the switch.
To charge the light, you will need to supply your own micro-USB cable. Simply plug the cable into the port on the light (under the rubber cover). A blue LED inside the light will illuminate, to indicate charging is occurring (turns off once charging is complete). In my testing, it took ~1hr 10mins to fully charge the light from very dim.
For more information on the overall build and user interface, please see my new video overview:
As with all my videos, I recommend you have annotations turned on. I commonly update the commentary with additional information or clarifications before publicly releasing the video.
As an aside, if you want to get an instant notification for every new review that I post here on CPF, you can subscribe to my YouTube channel (the vids go public at the same time). Just mouse over my logo watermark on the top right-hand corner of the video for the subscribe feature to open up. You may need to tap or click, depending on the platform you are using to watch.
The tube uses pulse width modulation (PWM) for its sub-max levels, but at two distinct frequencies
Tube Min PWM:
Tube Lowest ramp PWM:
For some reason, the Tube uses 500Hz PWM at the min activation level, and 3kHz PWM for all levels of the ramp (except max, which is full power).
What this means in practice is that those who are sensitive to PWM will be able to see if on the min level – but only the min level. The 3kHz PWM all other sub-max levels is undetectable in use.
Let's take a closer look at the ramp levels, to confirm this is actually PWM here:
Tube Lo PWM:
Tube Med PWM:
Tube Hi PWM:
And indeed it is. Negative deflections above indicate when the light is on – as you can see, as you increase the output level of the ramp, the light spends more time "on" during each pulse. Once you reach the max level, the light is on all the time (as you would expect). PWM frequency remains constant at 3kHz at all ramp levels (below max)
I consider this 3kHz PWM to be perfectly acceptable in use. You will not be able to detect it visually.
In case you are wondering about the TubeVN, the mod has no effect on the PWM feature:
TubeVN Lowest Ramp:
For these measures, I am using the Xtar VI01 "USB Detector" - basically a specialized USB current/voltage meter. This model has recently been favorably reviewed by HKJ here. I left the USB detector in place for all readings. Note that the voltage reading on this device refers to the input voltage (i.e., from the charging brick).
For the charging test, I started with Tube that been depleted down to a very low sub-lumen level, <0.1 lumens in my lightbox.
Initial charging current and input voltage of the nearly-depleted Tube:
As you can see, charging started at 0.11A and 4.85V input voltage. This is well below the maximum charge capacity of USB.
Charging current dropped steadily during the charging cycle. Here is one hour into the charge:
As you can see, charging is down to 0.02A at this point, and input voltage has risen slightly to 4.93V (which is pretty close to what I measure when no charging is taking place).
Charging in fact terminated within ~5-10 mins after this point.
As you can see, the blue charging LED has turned off, and the detector is reading 0A.
This charging time is faster than the rated 2 hours stated by Nitecore, but I suppose it could take longer if you discharged the Tube even further (i.e., far below <0.1 lumens).
A standby current drain is inevitable on this light, due to the electronic switch. I have not disassembled a functioning Tube to try and measure it though. It is probably no worse than a cheap squeeze-type keylight, and they usually last up to a couple of years before being completely drained.
In any case, regular top-ups with a charging cable won't hurt it, and are in fact a good idea.
Lights are about ~0.75 meter from a white wall (with the camera ~1.25 meters back from the wall). Automatic white balance used on the stock lights (to minimize tint differences.
Let's start with the keychain lights, with all Tubes on max. Note that there are some scratches on my white wall below, just off-center to the right.
Ok, the stock Tube is a lot brighter than your typical 5mm squeeze-type keychain light. For the comparison above, I am using a recent keylight supplied by Battery Junction (sold under the Titanium Innovations brand name). The Tubes have much better relative tint, with a lot less blue (although in absolute terms, I still find the Tube to be very cool white).
The TubeVN has a much higher max output, with no appreciable shift in tint (i.e., no dedoming here folks).
Let's see how it does against a couple of 1xAAA lights.
This isn't really a fair comparison, since the Preon P0 is a lower lumen light with a wider spotbeam-type beam pattern. But I think you'll find the Tube's max output is quite reasonable – similar to Hi on some of the older 1xAAA lights, or Med-Hi on some of the latest higher-output ones.
As you can imagine, no outdoor beamshots here …
Scroll down for direct measures.
All my output numbers are relative for my home-made light box setup, as described on my flashlightreviews.ca website. You can directly compare all my relative output values from different reviews - i.e. an output value of "10" in one graph is the same as "10" in another. All runtimes are done under a cooling fan, except for any extended run Lo/Min modes (i.e. >12 hours) which are done without cooling.
I have devised a method for converting my lightbox relative output values (ROV) to estimated Lumens. See my How to convert Selfbuilt's Lightbox values to Lumens thread for more info.
Throw/Output Summary Chart:
My summary tables are reported in a manner consistent with the ANSI FL-1 standard for flashlight testing. Please see http://www.flashlightreviews.ca/FL1.htm for a discussion, and a description of all the terms used in these tables. Effective July 2012, I have updated all my Peak Intensity/Beam Distance measures with a NIST-certified Extech EA31 lightmeter (orange highlights).
Let's mix things up a little, and start with a comparison of max and min lumen output for the Tube/TubeVN.
Since I had 4 functioning Tube samples, I thought I would present these with some basic descriptive statistics: mean (average) and standard deviation (SD). These are reported below as the mean +/- the SD.
In statistics, the standard deviation is a convenient way to directly compare the variation between groups in a consistent manner. For a normally-distributed population (i.e., the class bell-shaped curve for IQ tests, and many naturally occurring phenomenon), you can think of the mean as the center of the curve, and a single standard deviation unit as being the point on either side of the mean where 68% of the samples would fall within.
I'm throwing runtime into the table below as well, to the ANSI FL-1 standard of time to 10% ANSI max output.
First thing to note above is that my output measures suggest the Nitecore specs are fairly accurate – I get 0.6 lumens on average for min output (1 lumen spec) and 46 lumens on average for max output (45 lumen spec). The same goes for runtime – I get 62 mins on average for time to 10% (60 min spec). For all three measures, the SD is a fairly consistent ~10% (i.e., two thirds of the samples fall within ~20% of the mean).
I only had one sample of the TubeVN, but you can see it is significantly brighter at both its min and max levels, by ~180% and ~60% respectively. Of course, that is just a comparison to the average output – individual pairings could vary (i.e., the TubeVN on max was ~70% brighter than the Pink Tube, but only ~40% brighter than the Clear Tube).
Runtime on max on the TubeVN is of course reduced compared to the stock Tube. To see how efficiency compares overall, please see my runtime section below.
To put these results into context, here is a summary chart comparing to the classic 1xAAA lights, and the Titanium Innovations keylight:
The TubeVN certainly reached the level of max output commonly seen on 1xAA keychain lights (although is a lot less focused for throw, of course). Note that the min level is also increased on the TubeVN - it seems the current mod affects all levels on this light.
This is one area where I find the Nitecore specs to be a bit inflated – only one of my stock tube samples topped 80cd for beam intensity (spec is 150cd).
Let's start with a comparison of just max outputs, for all my stock Tubes and TubeVN. As always, my stated runtimes in the legend are time to 50% (see table above for ANSI FL-1 time to 10% measures).
On max, the Tube family looks to be very much like direct-drive for standard Li-ions. This is a highly efficient way to regulate output, given the current/resistance characteristics of Li-ions.
As demonstrated by the relative low standard deviations above, there is not a huge amount of variability between stock samples.
Not surprisingly, the TubeVN is higher output and lower runtime on max than the stock Tubes. Regulation pattern is a little different as well, as it appears to try to remain flat-stabilized for a bit before finally dropping off.
What happens at sub-max levels, where PWM comes into play?
For the analysis above, I am just using two stock lights and the Tube VN, and showing all at the max output (dotted lines) and at a fairly equivalent near-max output level of in the ~35 lumen range (solid line).
The Tube lights all still show a relatively direct-drive like pattern at this near-max level. There is also no obvious efficiency difference for runtime, as the TubeVN is intermediate to one of my "best" and "worse" performing stock Tubes. But given how hard it is to select exactly the same output level on the very fast ramp, these results should only be used as an approximate guide.
How does this compare to the Titanium Innovations keylight, or standard 1xAAA?
Ok, the standard 5mm keylight is definitely not in the same class as these Tubes. But as pointed out earlier, the TubeVN definitely reaches a max output level that is consistent with a number of 1xAAA keychain lights.
The relative efficiency of the Tube emitter (and/or capacity of its rechargeable cell) doesn't match XP-G2/AAA-class lights though, as indicated by the reduced runtime/output of the Tubes. Still, this is a phenomenal result for a 5mm-class emitter.
One of the five stock Tubes I ordered arrived defective, with some sort of circuit short. This is one thing you wouldn't have to worry about with the TubeVN, since Vinh tests of each of his lights before shipping.
While the output is "whitest" I've seen for a 5mm emitter, there is still some tint variation in the beam (with a bit of bluish-white tinted light in the center). Also, 5mm emitters will never be as "throwy" as reflectored lights.
The Tube uses pulse width modulation (PWM) for its low levels, but only the absolute min level is visually noticeable at 500Hz. All the other sub-max levels are at a visually undetectable 3kHz.
The Tube doesn't come with the required micro-USB cable, meaning you will have to supply your own.
Light ramps quickly (3.2 secs), with no pause at the max output (i.e., restarts immediately at min output and ramps again).
The Tube is a great leap forward from the typical 5mm squeeze-type keychain lights (keylights).
Not only is the Tube capable of much higher output (with much whiter tint), but it also has a continuously-variable control interface and built-in micro-USB recharging. Vinh's modifications make it even more impressive.
It's common for many flashlight dealers to hand out simple keylights with purchases. If you are like me, you probably have a stash of these slowly draining, dim, blue-tinted keylights lying around. Yes, you can technically change the 2016/2032 coin cell batteries in these, but it is fussy work and the results are not always stable. I usually just hand out whatever I have on hand to kids who visit on Hallowe'en.
I've long felt that there was a market for an inexpensive rechargeable version of these, and Nitecore doesn't disappoint with the Tube. Yes, it will cost you at least ~$10, but you are getting a well thought-out product. I like that you can jump to max or min from off, and ramp from on. That said, a slower ramp would have been nice (3.2secs is pretty fast from <1 lumen to ~45 lumens), as well as a defined pause once max is reached.
I don't know where Nitecore sourced the 5mm emitters for these, but I am frankly amazed at how bright they are (and how white). Yes, they are still very much at the cool end of the spectrum, but these beat any other 5mm emitters I've seen.
I suspect the main disappointment for some will be the lack of a bundled micro-USB charging cable. Personally, I would recommend Nitecore charge an extra buck or two per unit and include one (you can easily find them online for that price). Not a problem for those of us with Android phones, but not every iPhone user has micro-USB cables lying around their house.
In terms of variability, most of the stock Tubes I received were very close to each other in terms of performance (output, throw and runtime).
Vinh's current-boost modification only makes this light better. Max output is significantly improved. Output now rivals some of the classic 1xAAA lights (although the Tube/TubeVN will always be floody in comparison). Of course, Min output also went up on the TubeVN, but my sample was still well below ~2 lumens. And you can also rest assured that Vinh will spot and correct any obvious build issues (i.e., one of my stock Tubes was DOA for a circuit short).
I'm glad to see Nitecore has developed these – it's about time we had a rechargeable option in this class. I'm also glad to see that Vinh has given these one of his trademark circuit boosts. I hope they do well, and continued to be offered for sale some time.
TubeVN provided by Vinh Nguyen (V54) for review. Stock Tubes purchased from an authorized Nitecore dealer.