LUMINTOP SD75: A HUGE 4000 Lumen Flashlight Review (Lots of Photos)

(Unless otherwise stated, the information in this review is based on my own observations and measurements, not the official specifications.)

Ever since LED flashlights began taking off, I have wanted to acquire an ultra-high-lumen-output LED flashlight. Until now, I had not for a number of reasons, which I will discuss later in the article. After years of waiting I have finally acquired a 4000 lumen beast: the LUMINTOP SD75, and now I have tested this flashlight extensively and am incredibly happy with it.

Left - Right: Spiderfire P7, The LUMINTOP SD75, Samsung Galaxy S4 Phone

Left – Right: Spiderfire SSC P7 flashlight, the LUMINTOP SD75, Samsung Galaxy S4 phone.

While high-lumen flashlights have been available for a few years, none of them appealed to me. My biggest problem with them was that most had built-in batteries, a deal killer for me. When out hunting, or in an emergency situation, I want to be able to swap out dead batteries not wait a few hours for an internal battery to charge (that is, if a power source is even available!). Also, batteries degrade over time and I want to be able to replace the relatively cheap removable batteries, not purchase an expensive proprietary battery from the manufacturer.

A deep reflector and Cree XHP70 LED Lamp

The LUMINTOP SD75 deep reflector and Cree XHP70 LED Lamp.

My other problem with the previous generation of this class of flashlight, and most of the current generation is that they use multiple LED lamps instead of a single lamp. Multiple lamps helps with heat dissipation but results in a beam that almost round, but not quite 100% round. To get the heat benefits from multiple LED lamps, the lamps need to be spread as far apart as possible. In order to spread them apart, the lamp reflectors must be shallow and so not as tightly focused. An example of these multi-reflectors is below; compare it with the single deep reflector of the SD75 above:reflector

That enough of me discussing flashlights I do not like, let’s discuss the LUMINTOP SD75. It uses an LED lamp manufactured by Cree called the XHP70 (eXtreme High Power 70). This is a new LED lamp that is very efficient and heat tolerant and rated for 4000 lumen. Because of this, LUMINTOP is not having to overdrive the lamp to achieve the high light output, avoiding a decrease in life expectancy.


The Cree XHP70 Datasheet.

As far as looks go, it is a handsome looking flashlight. As you would expect the body is made from machined aluminum. It has a single button. Pressing and holding this button turns the flashlight on and off. Pressing and releasing it quickly changes modes. The head separates from the body to expose the battery module. The tail cap unscrews to allow access to the DC charging jack and USB ports for charging USB devices (more on this later).

LUMINTOP SD75 Flashlight-2

LUMINTOP SD75 Flashlight-5

The tail cap supports the SD75 well enough, but I would have preferred a flanged tail cap to give it additional stability.

LUMINTOP SD75 Flashlight-11

The body is threaded for a tripod and is supplied with a screw-in lanyard loop. I do not plan on using it with a tripod, but if I did need to used it with one, I would need an adapter because the screw hole is to close to the heat dissipation fins. The tripod screw hole should have been placed about an 1″ further towards the rear.

LUMINTOP SD75 Flashlight-12

It weights 2.28 lbs (1030 grams) with batteries installed. It feels lighter than it looks and is quite comfortable to carry around.

The SD75 is powered by four 18650 cells. These are not provided, probably due to shipping restrictions. The cells are inserted into a battery module and this is inserted into the flashlight. The battery module can be inserted either way up, which is a nice touch.

LUMINTOP SD75 Flashlight-8

18650 Cells in the SD75 Battery Module. (JUST FOR DEMONSTRATION. DO NOT MIX BATTERY TYPES)

Either protected cells or unprotected cells can be used. In the above photo, on the left, is an unprotected Panasonic NCR18650, my favorite brand (these power Tesla’s electric cars), next to it is a protected Sanyo 18650 (my second favorite brand). As you can see there is plenty of space for the longer protected cells.

LUMINTOP SD75 Flashlight-6

The flashlight can even be used as a USB battery bank by removing the tail cap and plugging in a USB device into one of the two USB charging ports.

LUMINTOP SD75 Flashlight-13

I had no trouble charging my Samsung Galaxy S4 mobile phone. One USB port outputs up to 1A and the other has a maximum output of 2A. A push button turns the power bank on and off. When on, five small LEDs light up to indicate the battery level.

LUMINTOP SD75 Flashlight-4

Even if you are not using the power bank, switching it on and replacing the end cap, with its transparent window, allows the battery levels to be easily monitored.

LUMINTOP SD75 Flashlight-1-2

LUMINTOP ships all SD75 flashlights with a small USB lamp. I guess it could be useful as a reading light when camping.

LUMINTOP SD75 Flashlight-18

The flashlight has four modes: High, Medium, Low and Strobe. LUMINTOP lists the specifications as:

  • High: 4000 lumens
  • Medium: 1800 lumens
  • Low: 150 lumens
  • Strobe: 4000 lumens

I do not have the equipment to test the actual light output from the flashlight. Comparing it to other flashlights, I think the lumen specifications are accurate. The strobe appears to be within the standard 15-20 hz range, and along with 4,000 lumens of light it is very disorientating.

I tested the runtime of the flashlight on High and Medium settings by placing the flashlight on a table indoors and recording how long it took to turn off. I used “protected” 3400mAh 18650 cells which cut out when the voltage gets too low. This is not an ideal test setup. A better test, which would result in longer runtimes, would be using unprotected 18650 cells and a fan to keep the flashlight cooler, simulating more realistic outdoor conditions.

I ran the tests twice and the runtimes I got were:

High: 2:05 hours
Medium: 3:45 hours
Low: I did not test but would expect low would get at least 36 hours, probably more.

If you are using this flashlight outside, or even just holding it in your hand, I would expect longer runtimes as heat would dissipate quicker.

During testing the tail of the flashlight heated up to about 110 °F (45°C) but dropped very quick as soon as I picked it up and walked around, moving air over the heat dissipating fins machined into the flashlight’s head. Let me reiterate my testing procedure represents the worst possible scenario. In normal use I would expect the flashlight to stay relatively cool.

The beam thrown by this flashlight has a “hot” center measuring about 10 degrees and a larger cooler beam measuring 60 degrees (please excuse my poor diagramming skills).

beam angle-1

It is incredibly hard to convey the brightness of a flashlight. The company advertises that the beam can be throw 650m (700 yards). I went to a valley near my home and standing on one side shone it across the valley, about 450 yards away. It was impressive how well it lit up the other side. I do not want to exaggerate, so let me be clear: It does not project daylight at that distance, but it was visibly lit up and far more detail could be seen that with just moon and starlight. I can see this flashlight being very useful when hunting at night or in a search and rescue situation.

The below photos were taken 100 yards away from the tree I shone the flashlight at. The photos were taken my with camera in Manual mode. As you can see there is ambient light and the photos would have been far more impressive had I taken it later that night, but in any case photos of flashlight beams only really serve for comparison between the different modes.

1 Off

Flashlight Off

Flashlight on Low beam

Flashlight on Low

Flashlight on Medium beam

Flashlight on Medium

Flashlight on High

Flashlight on High

The flashlight is IPX-8 waterproof and is supposed to survive for at least 30 minutes at a depth of 6.5 ft (2m). There are decent rubber o-rings that have been lubed with silicone grease on both the head and tail sections. The glass front it sandwiched between rubber rings.

LUMINTOP SD75 Flashlight-16

LUMINTOP SD75 Flashlight-14

I placed the flashlight in a container of water and left it running on High without any problems.

LUMINTOP SD75 Flashlight-20

LUMINTOP SD75 Flashlight-21

After taking it out there was no sign whatsoever of water penetrating the seals. Two replacement o-rings are supplied with the flashlight, which is a nice touch.

LUMINTOP SD75 Flashlight-22

Also included with the SD75 is an aluminium case, a wall charger (12v 2A) and a car charger.

LUMINTOP SD75 Flashlight-17

Overall, I am exceptionally happy with my SD75 and I am pleased I did not spend my hard earned money on a more expensive older generation of high-powder LED flashlight. The LUMINTOP SD75 is $190 on Amazon with free shipping. As of today (12/10/15) there is a coupon code listed on its Amazon page for 10% off, knocking the price down to $171 (I don’t know when it expires but the code is ZCLMTSDJ). For me at least, this represents great value. I would not hesitate to recommend the SD75.

Steve Johnson

Founder and Dictator-In-Chief of TFB. A passionate gun owner, a shooting enthusiast and totally tacti-uncool. Favorite first date location: any gun range. Steve can be contacted here.


  • Bart

    Looks pretty cool. Not a firearm, or really related to firearms

    • ak1134

      I disagree.. They are related.

    • BattleshipGrey

      Just need an adapter and it’s related.

    • Bart, we cover flashlights and have done so for many years. Knives too. We usually post on flashlight review each month.

    • ozzallos .

      The also cover customer service pet peeves. For reasons.

  • Some Dude

    Another goodie to mount on my mall ninja AR build.

    • Mall Ninja M2 more like it 😉

      The flashlight just lacks a remote switch

  • Badwolf

    Please make one with all the same features and incorporating the suggestions of Steve, but using AA/14500. Tnx!

    • 18650 are not very exotic. They are readily available and can be charged in the flashlight itself.

      • Sgt. Stedenko

        A 14550 is a lithium ion cell the same size as a AA..
        Delivers 4.2 volts vs the 1.5 of a AA. That means more power to drive the diode.
        My Four Sevens Quark AA can run either. The 14550 will drive the light brighter than a NiMH or alkaline.

        • I would be a little worried about frying an AA device if I accidently put one in.

          • Sgt. Stedenko

            Yeah, dont put them in a device not rated for 4.2 volts DC.
            They will definitely get fried.
            I wish my Zebralight AA would accept them though. I hate the short life of NiMH and alkaline cells.

      • Badwolf

        I agree. But still, nothing beats commonness of AA. You can buy it in almost any convenience store in any country. And as sarge mentioned, some lights such as the quark can accept both AA and 14500. The AA would give less output, but at least the light is still useable. So I would use the 14500 as primary, and AA as backup.

        • Josh Callejas

          go to any vape shop to buy your 18650 batteries, it’s the most common type used in mods, they sell chargers, and they’ll always have the best ones. I recommend purple efests, Sony vtc4s, and LG HE4s

          • Badwolf

            Thanks josh, good to know. But Im required to travel a lot. Vape shops may be common where you are, but in other parts of the country or the world not so much.

  • Hunter1911

    What is the difference between protected and unprotected cells? Is one or the other safer? Last longer? Etc?

    • Sgt. Stedenko

      Unprotected cells can be overcharged raising the risk of fire or explosion during charge. Protected cells limit the current during charge to prevent charging too fast.
      Both perform the same during discharge.

      • Hunter1911

        Thank you

      • Protected tend to cut out before fully discharged, so less battery life.

        • Joe Hathaway

          Unprotected allowed to run too close to fully discharged are trash–they cannot ever be recharged. Protected cells cut off before that happens–they have a digital chip which prevents overcharging, backwards installation, and current running through the cell unchecked from an unprotected battery that has shorted out in series with the protected cell. There are horrible tales online relating fires, serious injuries, and death from unprotected cells in various devices. About a buck more for protected cells is cheap, no?

          • I personally disagree. The ideal protected circuit draws no current and cuts out at exactly 3.2v. In reality they are cheap circuits, draw power (constantly discharging the cells) and have a cutoff that is too high.

            I would pay a few bucks for a really decent protection circuit.

  • Yimmy

    Very nice review, let us know if they have an update with a bottle opener.

    • Precious Roy

      I’ll wait for the Android version with salsa container, holster, fishing rod and CB radio.

    • iksnilol

      Did you know the Nagant revolver can be suppressed?

  • Sgt. Stedenko

    Too heavy.
    What’s the warranty like?

    • You need the mass to dissipate the heat. Only going to get lighter if using exotic (expensive ) alloys, or newer LED lamps come on the market that are more efficient.

      Good question re: warranty, I don’t actually know what it is.

  • Captain Obvious

    Small penis, big light.

  • Bill

    I’m wary. That’s a price I could afford, but seemingly too low for that kind of output. Made in China?

  • Mc Cain

    When 3,500 lumens is just not enough.

    • I expect 4000 will last me two years … then I will ***NEED**** 6000. Because POWER.

      • Hensley Beuron Garlington

        I concur with this rate of upgrading. LOL.

  • greek preparedness

    using different li-ion batteries is DANGEROUS. In fact the batteries should come from the same lot and grouped in use for LIFE

    • Sgt. Stedenko

      I agree,
      Seeing that hodgepodge of batteries makes my skin crawl.
      I guess some people have never experienced a Li Ion going poof and starting a fire.
      Sony learned the hard way using cheap cells in their laptop batteries can be a litigious event.
      AW protected cells for the win.

      • Cymond

        Maye you can tell me, do AW cells physically fit in the same space as primary cells? I have a few 123a lights that won’t take UltraFire protected rechargeable cells. I don’t want to order any more rechargables unless I know they’ll fit.

        • Sgt. Stedenko

          I have a Quark 123^2 which uses two primary CR123s. I can fit an AW 17670 in the tube, although it’s a little tight on the diameter (17 mm). I had to remove the adhesive label on the cell so it would slide in and out easily.
          I cant speak about single cell RCR123s, as I dont own any.
          The spec for RCR123 is 16 mm diameter and 340 mm long (16340).

          • Cymond

            340 mm would be over a foot long, but I know you meant 34.0 mm.
            I checked my UltraFire cells, they’re 35.6 long
            I got some AW’s for Christmas, they’re 34.8 mm long. I haven’t tried them yet. Hopefully that 0.8mm makes enough difference.

    • I agree, I only use the same capacity cells in a flashlight, but disagree they must come from the same group/lot. In fact, if they are protected it does not make much difference. I do recomend balance charging them regularly.

  • iksnilol

    Is there any website with guides and recommendations on building flashlights? I’ve wanted to build a flashlight for a while. But I’ve no idea how or where to source the parts.

    • greek preparedness

      candlepowerforums for the mild to wild,
      budgetlightforums for the down to earth mods

      • iksnilol

        Budgetlights it is.

        I’d just like something somewhat powerful that can fit in a pocket (without printing much) that uses AA batteries. The Nitecore SENS AA seems basically perfect but I wish it was more powerful. The 100 lumens are basically nothing in an abandoned tunnel. I found out the hard way.

        • Sgt. Stedenko

          The problem with AA alkaline and NiMH is they only deliver 1.5 volts.
          Run time and output is less than a comparable Li Ion 14500.
          Get a rechargeable Li Ion battery and enjoy guilt free lumens.
          I have a charger that accepts 14500 (AA), 17670 (2 x CR123) and 18650s. Ran about $20.
          Just make sure your emitter can handle the 4.2 volts of a Li Ion.
          Some companies like Zebralight make Alkaline/NIMH only AA flashlights. Running a Li Ion in them would fry the emitter.

        • Cymond

          All of what Sgt said.
          I have a cheap light from China that’s rated to use a 10440 battery. It’s rated at 160 lumens, but it gets hot very quickly and the battery doesn’t last long.
          You should get decent use out of almost any good CR123a flashlight, but be warned that most rechargeable batteries are a little longer than normal disposable batteries. As a result, I have several CR123a flashlights that won’t accept the longer batteries.
          You should also look at FourSevens .com. Their new version of the Preon is rated at 220 lumens and is about the size of a Sharpie marker ($50 usd). Also check out their Mini series, and maybe the Quarks. I don’t know much about their new ‘Knight’ model ($75 usd).
          Also check out the Nitecore SRT-5. It’s very small for an 18650 flashlight and produces over 700 lumens ($100 usd).

    • Start buy buying a cheap one then modding with with an upgraded lamp module.

      • iksnilol

        Yes, but where do you find improved lamp modules? Are they simply plug and play or do I need to solder stuff? Also where can one get the improved modules and switches?

        • is where I would start if buying a new module. Free shipping world wide.

          But yes, you are definitely going to need to solder. As for switches, I don’t know. Never town down the switches.

          • iksnilol

            Thanks, I will need to look into a solder station as well now. Finally have an excuse for it 😀

          • One word: Hakko (search for them on Amazon)

    • Sgt. Stedenko

      Candlepowerforums has all the info you could ever need.

  • Taofledermaus

    What man doesn’t love magnets and flashlights?

  • Hensley Beuron Garlington

    LMBO! Good example! I guess once we get to Deathstar power levels, or Starkiller Base levels. LOL.

  • Josh Callejas

    I’m actually glad to see 18650s in use for things besides vaping, I have a ton of spare batteries and chargers.

    • They are in everything. Vaping is just the latest use for them.

      They are an industrial standard. Almost all are sold packaged inside batteries or devices.

      Laptops all used to use them (many larger PC laptops still do), electric cars, USB battery banks, Sony cameras, LED video lights, industrial equipment all use them.

  • Secundius

    A company called Wicket Lasers, has a Flashlight called the “Torch”. With a 4,100-Lumen’s rating, but NOT an LED but Halogen and claim’s the Ability to Fry an Egg. Price is $199.95 USD…