Overview
This light was purchased by myself. I was not incentivised in any way to write this review.
The Nightwatch NS53A is a single 21700 cell hot rod flashlight that puts out 9900lm. This is one of the brightest lights for its size and is ridiculous.
The NS53A is one of the NSX3 options available. All the different NSX3 lights come with the same 21700 body but have different LEDs and possibly drivers. I went for the NS53A version, as it’s is the brightest.
This light is impressively bright for it’s size, thanks to the 3 CREE XHP50.2 LEDs.
It’s currently $55 from Neal’s Gadgets but there may be discount codes to bring the price down a bit. Different versions of the NSX3 are available from BangGood too, though not the NS53A.
Update: I’ve added amateur runtime graphs to this review near the end.
Nitewatch NS53A Specs
The Nitewatch NSX3 comes in 3 variants, with the “X” denoting the LED.
- NS23 – Luminus SST20
- NS43 – Luminus SST40
- NS53 and NS53A – CREE XHP50.2 3V
The NS23 and NS43 come in a few colour temperatures but the NS53A only comes in a cool white 6500K.
| Output | 9900lm |
| Weight | 167g (without cell) |
| Dimensions | 41mm head x 133mm length |
| LED | 3 x CREE 6500K XHP50.2 |
| Throw | 34kcd / 369m |
| Power | 110W |
The maximum 110W will only be when the cell’s at full charge (around 4.2V). This equates to around 25A, so a high spec 21700 cell like a Samsung 30T is required.
What’s in the box, manual, accessories.
The NS53A came in a thin cardboard box. The only marking was the 53A, as this is the XHP50.2 version.
In the box is a lanyard attachment, 2 O-rings for the tube, 1 O-ring for the head and a spare glass lens.
Appearance and quality
Nightwatch have fitted the NS53A with chunky springs, which are needed for the high current. They’re so thick that I’m guessing a spring bypass wouldn’t make much difference here.
Nightwatch have added 2 O-rings to the tail, which is unusual. There’s no IP rating from the manufacturer but it looks like it could survive a drop in water.
The threads are trapeze cut and the anodising is reasonably good. Turning the tail cap a 1/4 turn disconnects power, which is useful for safety.
The NS53A has big fins for its size, which help shed some of the heat it generates.
The switch is a reverse clicky, which means it switches between on and off when you let it go, rather than when you press. It makes a satisfying click. You can let it go half way when it’s pressed, which is useful for changing modes.
Physical design
Nitewatch’s NSX3s are around the size of a standard C8, with a slightly smaller head and slightly larger body (due to the 21700 cell). It fits in a jacket pocket well.
The NS53A can tail stand and head stand. Don’t head stand it while it’s on, or you’ll burn your table.
Comparisons
Some other lights for size comparison.
Interface
- Click: on / off
- Double click: change modes T-H-M-L
The NS53A I have starts on turbo mode (or outrageous mode, as I call it). This isn’t great for normal usage but is perfect for surprising people with how far flashlight technology has come. Apparently other NSX3 lights no longer do this.
Turning the light off and on again within 3 or 4 seconds switches modes down to high, then medium, then low. After low it goes back to turbo, or you can leave it off for 5 seconds, then it’ll come back to turbo again.
The light has a strobe mode, though to activate it you have to turn it on then switch modes within about 0.1 seconds. 9 times out of 10 when you change down from turbo it’ll go to high but occasionally if you happen to be too quick then it’ll strobe. I just did it and now I can’t see what I’m typing.
Light (modes, comparisons, beam, brightness)
The LEDs are too cold for my liking but colour quality isn’t the reason you buy this light. For 6500K (cold white), they’re actually not too bad. These are 3V XHP50.2 LEDs, which CREE themselves don’t seem to mention. XHP50.2 LEDs are basically 4 XP-G2 LEDs stuck together.
Being a triple, the beam is fairly floody, though it still throws almost as far as a basic Convoy C8.
The claimed throw of the NS53A is 396m, which is a bit more than the XP-L HI Emisar D4 (284m) and a bit less than a BLF Q8 (450m).
There’s no beam artefacts visible, despite it being a tripple.
Output, runtime, and efficiency.
9900lm. That’s all you need to know.
Nitewatch state 9900lm for this light. I don’t have any way to measure it properly but when ceiling bouncing, it appears about the same as 5000lm Q8 and 4300lm D4 combined.
It’s called turbo for a reason though. It gets very warm but the main issue with the light is that a single cell won’t last that long.
A 3000mAh cell (like the Samsung 30T) means it can put out 3A for an hour. The 25A or so needed for turbo is over 8 times as much, which means in a perfect world it would last only 7 minutes on turbo! (It’d be lower, as the cell is less efficient at 25A and lots of power will be wasted as heat. You can bring more cells and switch them but at a certain point you may as well get a soda can light.
The light starts to step down after about a minute, though still stays bright for a while. Supposedly it steps down when it gets to 50°C, though I haven’t tested this.
Medium and low modes don’t get hot though, and that’s where this light is actually pretty usable. “Low” is still at least a couple of hundred lumens and it’ll hold a “medium” brightness that’s almost 1000lm.
Update: Runtime graphs
Following some feedback on Reddit, I’ve created some runtime graphs, using the Ceiling Bounce app and an old Android phone. These graphs should give a good indication but please take them with a pinch of salt. These were all done on a Samsung 30T 3000mah 21700 cell.
Turbo
From a 4.2V cell, I measured the NS3A stepping down from turbo quicker than I thought it would from normal use, dropping to 50% brightness in just over a minute. It might be that holding it helps dissipate the heat, making turbo last longer.
Step down is fairly noticeable when you’re looking out for it but isn’t really noticeable outdoors with normal use.
After a minute, the head of the light measured 66°C. After 5 minutes it looks like the thermal regulation eased off. Putting it on high (50%) again only lasted another 2 minutes, getting to 74°C. Bumping it up to turbo again (twice!) got it back to about 80% brightness but it was so hot (80°C, 176°F) that it only lasted a few seconds. Don’t try this at home, or you may damage the light. At the end of this dangerous experiment the cell was at 3.9V, so would have had enough juice to do almost the same again.
High
From my rough tests, high mode is starts at 50% of turbo. It’ll be a 50% PWM duty cycle, though you can’t see the PWM.
The weird thing with high mode though is that it got brighter for the first 30s or so, before getting dimmer. I can’t explain this, though presumably the driver gets confused when the light starts off cold. The NS53A still gets hot on 50% (not surprising at almost 5000lm).
Turning off and on to get back high again once it’s had time to cool gets you back to 50% brightness again, though subsequent resets started to lose their peaks due to the cell voltage dropping.
The NS53A lasted around 30 minutes on high, though might of that was when it had stepped down and needed resetting. After this time, the light flashes, giving a low voltage warning. The cell measured 3.3V.
The thermal regulation on high works but it’s not very good. Ideally it would step down faster to a sustainable level and not need resetting all the time. From memory, it works a bit better when walking outdoors.
Medium
From the high runtime chart, you can see that medium just under 10% of turbo. That’s between 600 to 700 lm, which is close to a turbo level in many single LED 18650 lights.
The light barely gets warm on medium and keeps going at about 800 lumens for nearly 2 hours on a 3000mAh cell. It then drops down to low.
Low
Low is 25% of medium, between 150 and 200lm. This is still plenty of light to see by and brighter than most headlamps. I didn’t do a runtime test but would expect it to last over 7 hours.
Conclusion
If you want something that’s a step up from a pocket hot rod (like an Emisar D4 or FW3A) but still smaller and lighter than a soda can like an Emisar D18 then a single 21700 light with 3 LEDs is a good middle ground.
The Nightwatch NS53A is good quality and performs as you’d expect.
There’s a few other single 21700 lights with similar performance, which are worth a look out too, though the Nightwatch is the cheapest.
| Light | LEDs | Lumens (on turbo) |
| Fireflies E07 | 7 x SST20 or XP-L HI | 6900 |
| Nitecore TM9K | 9 x XP-L HD | 9000 |
| Nightwatch NS53A | 3 x XHP50.2 | 9900 |
| Lumintop FW21 Pro | 3 x XHP50.2 | 10,000 |
| Nitecore TM10K | 6 x XHP35 HD | 10,000 |
| Imalent MS03 | 3 x XHP70.2 | 13,000 |
Dave's Tech Reviews 
Awesome! Nice review
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How did you charge the light?
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Thanks for the comment. The light doesn’t have built in charging but it takes standard rechargable 21700 li-ion cells. I mostly use a XSTAR VC4 charger or a XSTAR PB2S charger for these but there’s loads of other chargers that will work with them.
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