XTAR D36 5800 Flashlight Review

XTAR D36 5800 Flashlight Review

The XTAR D36 5800 is a flashlight made for diving. The light has two emitters and built-in charging. Read on for thoughts and testing!

Official Specs and Features

Here’s a link to the XTAR D36 5800 Flashlight product page.


Just one version of this light!

Price and Coupon

Looks like these are going for around $330, but if you buy on the official XTAR Alibaba site there’s a $20 off for purchases over $200.  Unfortunately that doesn’t even cover shipping.

Short Review

While this light isn’t one intended for my usual EDC style use, it seems like it’d be very fitted for actual diving.  The buttons are large and easy to press.  The output is good (though not measuring up to the claim) and the modes are almost all dead level flat.  (Even the highest mode seems to only step down because of temperature, which will not be a problem underwater.)

Long Review

The Big Table

Spot + Flood output:

XTAR D36 5800
Emitter: Flood + Spot
Cell: Internal
Runtime Chargetime
LVP? Yes
Power off Charge Port with no Cell?
Claimed Lumens (lm) 5800
Measured Lumens (at 30s) 4000 (69% of claim)^
Claimed Throw (m)
Throw (Calculated) (m) 247.5
Candela (Calculated) in cd (at 30s) 529lux @ 5.38m = 15312cd

Spot output:

XTAR D36 5800
Emitter: Spot, Cree XHP35HI D4
Runtime Chargetime
Claimed Lumens (lm) 1600
Measured Lumens (at 30s) 1100 (68.8% of claim)^
Claimed Throw (m)
Throw (Calculated) (m) 227.1
Candela (Calculated) in cd (at 30s) 688lux @ 4.33m = 12899cd

Flood output:

XTAR D36 5800
Emitter: Flood, Cree XHP70.2 P2
Runtime Chargetime
Claimed Lumens (lm) 4200
Measured Lumens (at 30s) 3300 (78.6% of claim)^
Claimed Throw (m)
Throw (Calculated) (m) 98.2
Candela (Calculated) in cd (at 30s) 145lux @ 4.078m = 2411cd
All my XTAR reviews!

^ Measurement disclaimer:  I am an amateur flashlight reviewer.  I don’t have $10,000 or even $1,000 worth of testing equipment.  I test output and such in PVC tubes!!  Please consider claims within 10% of what I measure to be perfectly reasonable (accurate, even).

What’s Included

  • XTAR D36 5800 Dive Light
  • XTAR BP36-3500 Battery Pack
  • Charge cable (Wall plug to barrel plug, 12V)
  • Spare o-ring
  • Lanyard with rubber cover
  • Latching plastic carry case

Package and Manual

There’s no box with this light, because it ships in a latching plastic case.  The case doesn’t have holes for locking.  There are stickers describing the light and also specs and features.

Two latches.

Here’s the manual.

Build Quality and Disassembly

Of course this light must have impeccable built quality, if it’s to be used on dives.  Everything about it supports the notion that it’s fit for this task.

The light is built with long tight threads on the tailcap.  Not only that, the body is one of the more difficult lights to unscrew that I’ve handled – that’s probably good.  Built this way, it’s practically impossible for the light to accidentally be dislodged and wetted.

The switches are also heavily waterproofed.  There’s not a lot of grip surface on this dive light but that’s likely intentional.  You’ll necessarily use the wrist strap, so the grip becomes superfluous: it’s probably more important that the grip isn’t overly grippy.  So there’s one rubber area right around the head, diamond pattern and thin knurling, and that’s it.

The body only comes apart at the tailcap; I didn’t disassemble it further.

The threads are thick and the lube is very thick too – much thicker than normal flashlight lube.  The threads are very nice but you’ll likely need gloves or a gripper on, to get the cap fully tightened.

The battery pack is not able to be disassembled.

The electronics end of this light has nice thick springs – three springs.  The battery pack has a positive, negative, and common connection.  To be sure, I don’t know why this is.  Also,33333 the battery will fit in only exactly one orientation, and it’s not possible to get the battery into the light in any other way.

This light is Waterproof IPX8 (Underwater 100 meters) rated, but I imagine I don’t have any water around me more than 10m deep.  I tested the light in water, but I didn’t do any diving.  The light works fine after this wetting.  I also manipulated the buttons while it was underwater, with no issues whatsoever.

Size and Comps

Officially this light weighs 454.3g, and is 57mm (Head dia) * 52.5mm (Body Dia) * 167.5mm (Length).

Here’s the test light with the venerable Convoy S2+.  Mine’s a custom “baked” edition Nichia 219b triple.  A very nice 18650 light.

Retention and Carry

The main means for carrying this dive light is the rubberized lanyard that attaches on this tailcap loop.  This is a firm connection.

This loop is also not removable, which means the light can not tailstand.  Not that you’d need it to, since it’s very specifically a dive light.

The knurling is present but very shallow.  I like this knurling, but it’s not very grippy.  There’s also a tripod mount on the head end of the light, which isn’t a terrible balance point.

Power and Runtime

The D36 5800 runs on the included battery.  It’s a 10.8V (nominal) battery pack is almost assuredly built of three 18650 cells in series.  I expect these are high capacity, low drain cells, since the claimed capacity is 37.8Wh.  This is probably a good choice for this dive light.  I don’t dive but mainly because I’m chicken, and I’d want a 100% certain tool if I was diving – XTAR is certifying that the battery is acceptable, instead of leaving it up to the user to pick any random cells.  This is especially important since they’re in series.

The battery (and yes, “battery” – a battery is made of cells.  Normally our lights use cells (singles), but this light uses a prepackaged set of 3 cells!).  The battery has three terminals – that’s unusual – maybe someone will explain it in the comments.  There’s a positive and negative terminal which read 12V across when full. Not sure what the common terminal does!  I will say that this setup meant I wasn’t able to test the current drain for each mode.

As I said above, the battery is keyed.  It’ll only go in one in exactly one orientation.  As seen at left, it’s not right.  At right, the battery is in place properly.  The tailcap does not have to be installed in order for the light to operate.

I tested the output on 5 modes.  First, the highest output, which is both emitters working full force.  The claim is 5800 lumens, and I measured around 4000.  That’s quite a difference in reading vs claim.  I have no special explanation for that, but I will say that my measuring device is an amateur, homemade device.

The stepdown is at around 10 minutes – either way 4000 lumens for ~10 minutes is good.  Very good, and that’s just with fan cooling.  Note the temp spike right at the stepdown – I expect that the stepdown is temperature-based (sensibly).  So underwater, where heat won’t be an issue at all, this light could potentially churn out 4000 lumens (or more!) for much longer.  The stepdown is to around 1100 lumens, then another around 800, and then the light shuts off.  The OLED gives warnings, and always displays the amount of time calculated to be remaining on that mode, so it won’t necessarily leave you stranded.  But the shutoff is quite abrupt with little fade, and the light does not come back on.

The highest mode with a single emitter claims 4200 lumens, and I measured around 3200 lumens at 30 seconds.

Below is the middle mode of the flood output, of 2100 lumens.  I measure it at around 1700 lumens and the output is astonishingly flat for over two solid hours.

The highest output with the spot emitter has a lower output but is also astonishingly flat.


With the included battery, must also be built-in charging.  XTAR includes a wall wart charger, which outputs 12V at 2A.  The barrel plug is just a common 12V barrel plug.

I jumped through some connection hoops to log a charge cycle.  I won’t claim this cycle is indicative of charging in a perfect scenario, but we can at least be given some idea that the charge current is around 1.3A, up to 1.5A, and that’s at 12V.  So 1.5A is around 18W, a non-trivial rate.  This also shows that the capacity is around 3400mAh, too.

User Interface and Operation

There are two buttons on the D36 5800.  They’re under an OLED screen.  The buttons are very proud, very round, and quite clicky.  There’s also nothing else on the light like them, so it’ll be impossible to mistake them for any other part of the light.

Here’s just a brief rundown of what the display does.  The light has two images of output – when both emitters are on, both are shown on the display.  When one or the other is on, one or the other is shown on the display.  It’s useful to memorize which is which, but the icons are also specific.  The flood beam has a “crown” shape (flared outward) and the spot has a more “straight upward” icon.

Each mode also displays the remaining runtime.

We’ll call the rightmost button the “Power” button, and the left-most button the “Mode” button.  They aren’t labeled otherwise.

Here’s a UI table!

State Action Result
Off Click Power Button (PB) On (4200 lm Flood)
On Click PB Emitter option advance (Flood, Spot, Flood + Spot, Off)
Off Click Mode Button (MB) Lock and battery capacity display
On Click MB Mode advance (HML direction)
Flood Hold MB 1.5s Blink 2100 lm Flood
Blink or SOS Click MB Return to previous mode
Blink or SOS Click PB Advance to Spot modes
Spot Hold MB 1.5s SOS 750lm Spot
Off Hold PB 3s Lock
Locked Hold PB 3s Lock, to 4200 lm Flood

Yes, unfortunately as far as I can read the manual, the only way to get the light to OFF is through the very highest output mode.

Modes and Currents

Mode Mode Claimed Output (lm) Claimed Runtime Measured Lumens Tailcap Amps
Flood+Spot 5800 45m
Flood High 4200 74m
Flood Med 2100 148m
Flood Low 1200 342m
Spot High 1600 155m
Spot Med 750 407m
Spot Low 400 892m

LED and Beam

There are two emitters in this light.  They are Cree XHP35HI D4 (for the spot) and Cree XHP70.2 P2 (for the flood).  Both are great choices for their respective uses.  The bit XHP70.2 has a white reflector, which is very shallow – not really much deeper than the dome is high.  The Spot emitter has an orange peel reflector, which isn’t very deep.

Below, view a beamshot on the Flood+Spot output, of a claimed 5800 lumens.

Next is the Flood output, three modes.

And finally, the spot output, of three modes, too.

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

There really are no low modes on this light, so it’s hard to compare this to a low output light like the BLF-348.


What I like

  • Seems like a light built well enough for diving.
  • Dual-beam output

What I don’t like

  • Off requires going through the Highest output
  • Tailcap is difficult to tighten fully
  • No proper low mode (is that needed in a dive light?)


  • This light was provided by XTAR for review. I was not paid to write this review.
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12 thoughts on “XTAR D36 5800 Flashlight Review”

  1. Color temperature? Apologies if you mentioned it, didn’t see it. What do you think about CRI?

    1. I didn’t mention it because I don’t think XTAR mentions it. The flood beam is much warmer than the spot beam.

  2. Iván Guardia

    I have got one D36 six month ago and I haven’t use it for a long, the battery pack (BP36) rans out and now it is not able to charge it self.

    Doy you know if I can order a battery pack or there is any tip to re-activate the BP36?.

    Many thanks in advance.


    1. Do you have a power supply? You can probably “bump start” it by properly applying voltage to the contacts.

      1. Thanks for answering. Yes, I have an external power suply and certainly I thought to conect +contact and -contact to 12V. Do you think it is the right way to “bump star”?.

        The COM contact confuses me. Between + and -, I got 3,2V, between + and COM I got 3.0V. Not sure if COM is “COMMON” or “COMUNICATION” for some kind of sensor (referening to the question in your review).

        I consider this XTAR D36 flaslight a really superb option for diving photografy and video. It’s a pity if I finally not able to reactive the battery pack. I would like to recommend it to diving mates.

        1. Yes exactly what I mean about bump starting it. I am not saying thats…. a good idea really… I don’t know. But it could possibly work. At least to where the internal charging will work!

          1. I tried to push 12v between +contact and -contact of the battery pack and it hasn’t worked.

            Now, I’m going to try to disassenble the pack and change the inside three 18650, at the same time I will try to discover what the COM contact is and if I am able to replace the 3×18650.

            I am frustated because the X36 is a great diving flashlight but there is no replace for the battery. XTAR DOESN’T answer me and I feel alone with this product with no support at all.

          2. I tried to push 12v between +contact and -contact of the battery pack and it hasn’t worked.

            For reference…. I have done this and I know it works.

    2. The same problem happened to me and I repaired it myself. You only have to buy 3 li-ion 18650 batteries and the quality does not matter. You will use them to revive the flashlight battery only.
      Connect them consecutively until you have a total voltage about 12V and you will connect the positive to the positive and negative with the negative for only 30 seconds and not increase then put the flashlight battery in the usual charger and will definitely work

      1. Well in this case he has a bench power supply….

        But yes generally that’s right!

      2. I already tried it.

        On the other hand I spoke with XTAR staff and they agreed to send me a new battery pack.

        Thank you very much XTAR, I will trust you for next orders because you have solved my problem and you are close to the customer.

  3. ChinookOutdoors

    I would say a lower mode (~20 lumens) is nice in a serious dive light intended for cave diving purely from the runtime perspective. Otherwise, I just find them to unnecessarily clutter up the user interface. Otherwise, I carry spare batteries which I switch out topside so I can run one of the higher outputs without worrying about killing the batteries. The only time I really find a lower mode useful (100-500 ish lumens) is when there’s a lot of particles or silt reducing visibility. The more lumens you try to push through crappy visibility, the more light bounces back at you making it difficult to see what little light does cut through the murkiness.

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