New cheap 26650 diving light at DX

You are right, always some issue with these little lights isn’t there? I was looking at a previous review I guess and got them mixed up… 1.5a does stink, and with a 26650 too. Otherwise it looks nice with a magnetic switch, 8 modes and T6 U2, why the sabatoge of 1.5a and 500 lumen I dont get, heat wouldnt be much issue with those fins (or under water thats for sure), seems like it would be only a couple dollars more for the manufacturer to make it a good/great light :stuck_out_tongue:

Maybe they think advertised run time is more important than output for some reason? I doubt many will actually use it for diving as a primary use, and with super/high/med/low mode, you extend runtime by keeping mode lower…

If i needed a diving light i would not trust a DX one, but 1.5A is not so bad you know, its over half what you would get with 3A, you could sinkpad it and use an xm-l2 (higher voltage won’t be such an issue at the lower drive current), and get presumably get most of the lumens you would at 3A (i have not done the math, just off hte top of my head)

Mind you, i am assuming it actually is 1.5A

DX managed to ship the light today. 5 days for shipping a new light, not bad at all.

The waiting continues.. ;)

4 of them are blinky modes :party: Who says disco is dead?

can’t wait for the review.

I like its grayish-black handle. Looks like a very good FL. I’ll wait for your review.

I received one during my no-post-waiting-for-admin-receiving-gifts-period. I'm working on writing review, but here's some sneak preview:

Pros:
- Build quality is good (for the price)
- Seems to be water resistant (double O-rings everywhere, thick glass lens)
- Parasitic drain is very small & negligible (0.005mA)
- Uses either 26650 (plain) or 18650 (with sleeve)
- Well driven (up to 3.0A in my initial tests)
- About 500lm OTF (on par with BLF A8)
- Modes are well spaced (100%, 50%, 30% & 10% of TC current)
- Magnetic switch works well (but doesn't have a real control ring UI - Good/bad, not sure. Haven't formed my final opinion about this..)
- From middle (= off):
- Turn left for normal modes
- Right for blinky modes (= no blinkies if you don't want to use them)
- No memory, first turn left = High
- Off & back to left = next mode (H-M2-M1-L)
- Off & back to right = next strobe mode (SOS-1-3-9Hz strobe)
- Pill & reflector form a nice, solid assembly
- High PWM
- Anodized (& lubed!) threads at tail -> can lock out

Cons:
- Emitter to pill thermal path is weak (small mod would make it much better)
- Doesn't tailstand (due the tail design)

=> Recommended for $22.90, highly recommended for $17.90


Some more photos:

I recently bought one of those for $20 at Meritline.com
I had tried one of their bright green plastic cheapies ($13). That one had 2 seams across the double O-rings and an actual divot under one of them. I spent 20 minutes with fine sandpaper improving it. It worked but seeped a tiny bit on a dive. Not suitable for diving. :expressionless: The light was not as bright as the light being discussed and it has a broader beam. It measured 3W/0.84A with a fresh 18650.

This light has been on 3 dives and so far is fine. I did clean up the threads and O-rings before diving. The silicone O-rings are not top quality as 2 of them have a bit of a ragged seam. On the last dive with a fresh 18650 I compared it to my main dive light, a 5-LED canister driven by 2S2P 18650 Tenergy batteries. These are custom lights made by a local retired machinist. They are very popular in our murky NW water.

This light is a bit more focused than my canister light, and just about as bright in the focal area when fresh. I does fade with voltage drop and at the end of an hour dive it was slightly behind the canister. The whole light is actually a bit smaller than my canister light head, which is made from a modified D-Maglite.
I’m a bit concerned at the longevity of the switch. I rinse after dives and have been putting a little liquid silicone into it after it dries.

I just got a 26650 for it and have not done a dive with that yet. It should sustain the output longer.
So far I’m quite impressed. :slight_smile:

Note-first posting.
I’ve been lurking on this forum for about a week having stumbled across it researching Lion batteries. Some are real junk. :Sp but you guys know that.
I’m mostly active in the RC and scuba communities. RC electric is heavily into batteries. Scuba is heavy into powerful lights. Thus my interest here.
Up until this light came up many of the ‘cheap Chinese’ lights simply did not sound suitable for diving. Light reliability is critical in NW diving. But, for $20 I thought I’d take a chance based on the description and pictures. This thread was just too timely to pass up.

Welcome to BLF flydiver! Looking forward to hearing how that light performs on a dive.

Couple questions since I’m new at LED mods.
How would I do this?: [Emitter to pill thermal path is weak (small mod would make it much better)]

I did not take the lens off. Is there an O-ring under that? Pictures don’t show well there.

Tail stand? It’s supposed to be a dive light, at least that’s the way I interpret it. It has a retainer loop on the tail that is critical for diving. I don’t see that as a con for this light.

Welcome to BLF flydiver! You'll love being here! :)

Rinsing is always a good idea, but I wouldn't be too worried. The switch is magnetic and there are no other mechanical parts than the metallic spring and small pellet (which are used to lock the switch to on / off positions). I would add some vaseline to the spring. Those parts will rust anyways, but I bet they'll last quite a long time. The spring is easy to replace if needed, but the pellet is very small.. So small that I lost it already. (Be careful when disassembling! The pellet is shot off as soon as the ring is taken away!) Not sure where to find a replacement..

See photos below.

Magnet side of the switch. Magnet is located in the plastic ring, body has a groove allowing it to move to on & strobe positions:

Hole & spring. Pellet should be on top of the spring.. (note also the notches in the plastic ring):

This light has basically a dreaded hollow pill, see below (reflector & pill assembly opened from middle seam):

The mod would be simply filling the hollow part with copper (or similar). For example couple of suitably sized coins would do. Idea is to have some metal under the emitter star and touching the sides of the pill, allowing the heat to escape from the emitter.

[quote=flydiver] I did not take the lens off. Is there an O-ring under that? Pictures don't show well there. [/quote]

Yes. There is a thick O-ring, sitting on a ridge, partially glued in to keep it's position. The lens presses that down so that it will tighten between body, reflector, and lens, sealing the head well. You could apply some silicone when opening the head for modding.

The O-ring can be seen well in this photo:


[quote=flydiver] Tail stand? It's supposed to be a dive light, at least that's the way I interpret it. It has a retainer loop on the tail that is critical for diving. I don't see that as a con for this light. [/quote]

I fully agree, but this light is so affordable that it will be bought also by non-diving purposes. So I thought it's good to mention that.. And of course there might be a situation where you come from a dive, go to your cabin, and electricity goes off -> tail standing light would be useful then. ;)

Unexpected and painful

That pill is a bummer. :expressionless:
Everything else looks good too.

Thank you for the great pictures and explanations. My level of understanding just took a notch up.
I’ve got other lights so using this above water is not an issue. Obviously I have some great cooling in NW water but I gather the path from the emitter to the sides isolates it so even though I’m cooling the body, the emitter may not be getting cooled properly. Hmm. That could fry it over time?
Is that unit simply pried apart? Can’t be a screw because of the wires.
I’m used to using PC thermal paste, but that won’t hold things in place I would guess. For this mod do you get some kind of thermal glue?

In my Underwater Kinetics SL3 the emitter has a direct track to a sleeve the length of the light to help cool it. The whole exterior unit is plastic so that compromises the transfer a bit. The SL3 kind of my standard for this kind of light. The SL3 is a very good NW backup light or main tropical light. UK has excellent customer service. For diving good customer service is very nice indeed. I’ve been through 3 of them, none my fault, and they’ve replace them all. I’m sure that exchange is now negative $$ for them.

Note-sorry you lost part of the switch taking it apart to show me. Should I venture to do that I’ll keep it in a plastic bag. May I suggest getting some silicone grease from a scuba shop instead of Vaseline for assembly. I think Vaseline is petroleum based. Though this has silicone O-rings they are often neoprene (petroleum based) in dive gear > like dissolves like, so we avoid petroleum products. Regulators are breathing life support with lots of O-rings in them so we avoid petroleum for that reason too. You really don’t want to be inhaling that kind of stuff.

No problem. Glad if I could help.

[quote=flydiver] I've got other lights so using this above water is not an issue. Obviously I have some great cooling in NW water but I gather the path from the emitter to the sides isolates it so even though I'm cooling the body, the emitter may not be getting cooled properly. Hmm. That could fry it over time? [/quote]

Yes. That's exactly why hollow pills are evil, and why I'm planning to mod my light.

[quote=flydiver] Is that unit simply pried apart? Can't be a screw because of the wires. [/quote]

It is a screw. Wires can be kept straight if you loosen the driver first (it is held by a retaining ring, see below)

[quote=flydiver] I'm used to using PC thermal paste, but that won't hold things in place I would guess. For this mod do you get some kind of thermal glue? [/quote]

I thought of taking the driver off and simply soldering a chunk of metal to the pill (= lower section of the assembly)

[quote=flydiver] Note-sorry you lost part of the switch taking it apart to show me. [/quote]

Not your fault. I did it before you even asked. :) Just a bad habit taking all my flashlights apart and taking photos. ;)

[quote=flydiver] May I suggest getting some silicone grease from a scuba shop instead of Vaseline for assembly. I think Vaseline is petroleum based. Though this has silicone O-rings they are often neoprene (petroleum based) in dive gear > like dissolves like, so we avoid petroleum products. Regulators are breathing life support with lots of O-rings in them so we avoid petroleum for that reason too. You really don't want to be inhaling that kind of stuff. [/quote]

Good point. I actually use silicone grease for flashlight threads, but I thought that vaseline would better keep the rust away from the spring.

My preference would still be silicone, especially for O-ring, but I use it on threads too.
I use ‘grease’ for bearings.
Can’t say I use Vaseline for anything. Probably got some way in the back of the medicine cabinet about 20 years old.

Useful picture for getting inside the unit.

I had this light a while back, it was ok but didn’t like it enough to keep it. I gifted to a buddy at work.

Here's how I modded this light.

The inner diameter of the upper part of the pill matches 5 Euro Cent coin pretty well, so I don't need to go to hardware store.. ;)

However, stacking coins on top of the existing ridge would make the emitter to sit too high => some work was needed.

First I dremeled some aluminum off:

Then continued with dremel and made holes for leads:

Then, again with dremel, smoothened the coins:

The bottom wasn't exactly leveled, so I added some desoldering braid and solder to straighten the coins:

Finished pill from above:

Add some Fujik, emitter, and solder leads:

Done. Much better thermal transfer.

While doing this I figured that a blob of solder could work as replacement for the lost pellet. And it did! So the light is again fully functional. :)

Of course the emitter in the last picture was there only for presentation purposes.. :)

Now the light has XM-L2 T6 3C emitter on SinkPAD, resulting nice NW tint and about 800lm OTF (after 30s, of course). I'm happy!

great job and shots :slight_smile:
I ordered 1 too with the 5$ GC, the heat dissipation looks poor the 5 cent coin is copper only externally, inside as you can see sanding is steel, that will not help thermal dissipation right?

Ever wondered how is the thermal conductivity of the nordic gold, (10, 20, 50 cents) is 89% Al and 5% Copper 5%zn and 1% stain so in the paper should be good but how in fact mixing and shaking all? anyone know that?

Btw destroy the money is illegal XD

I didn't know that 5 euro cent coins are not copper before sanding them, but decided to continue because steel is still 2000x better than air. ;) (and "only" 4x worse than aluminum / 7x worse than copper)

[quote=MixoMaxo] Btw destroy the money is illegal XD [/quote]

Not in Finland :evil: