Ultrafire DV-S9 diving light?

Just got one, beautiful little light, wondering if anyone has one and “dived” (haha) into it yet.

Takes a 26650, or 18650 with the included tube, has a switchless tailcap that covers 3 O-rings. Everything else seems to be put in through the front lens side, ’though I haven’t opened that up yet. Tempted not to (and risk ruining any seals).

There’s a magnetic switch, a little captive slider with magnet, no opening, slot, nothing. Inside looks like a Hall-effect sensor that reads relatively-speaking how close the slider is, and sets the light brightness accordingly.

There’s a slight “jump” from off to its lowest setting, and v/v. Also, once you get pretty bright, there’s also a slight jump to full-tilt. Nothing objectionable, at least not to me.

Obviously, this critter is always “on”, at least as far as sensing the switch, so there’s some parasitic drain. The threads aren’t fully anodised to the point where you can do a tailcap lockout on it. In fact, with the slider set to “on”, just putting the cap in place makes the connection before even getting the threads to engage. So that means not keeping the cell in the light 24/7.

Gotta say, though, the color is a beautiful shade of indigo, and pix don’t really do it justice. The red trim is a nice touch, too.

So… anyone else have one? Played around with it any? Solved how to keep the cell from draining when not in use? :smiley:

edit: added pic below

Did some poking and prodding, and with cheapo meter-leads, it draws a hair over 2A when running wide-open. Imagine with a direct connection (or thicker leads), it’d be more, maybe even the specced 3A+.

It also has a parasitic drain of pretty much exactly 10mA for the Hall-effect sensor. Not too bad, probably as much as a lighted tailcap.

And it does have a TCLO! Only an eighth-turn or so is enough to lock it out, so if you’re going to be keeping the cell inside, make sure you lock it out first.

Only negative I can mention is that the LED tint is a little bit on the greenish side. Not nearly as bad as my Quark 2AA-X, which is really noticeable, but still tinged enough for me to notice (Mr Tint-Snob).

Really nice light, all in all… think I’m going to get another one while the getting’s good! :smiley:

Hi. Lightbringer,

Thanks for your review.

Any links to the light?

S-L :slight_smile:



and just in general


right from the horse’s mouth.

Pretty pix, better’n I can take in a pinch. :smiley:

Few if any reviews, though.


Many Thanks for the links.

FT seems to have the best price for me.

All China on Holiday in a Day or two, so will probably look at this again in February sometime.

Did you find this has visible PWM on the lower end of the variable mode?

S-L :slight_smile:

P.S. I have modded lights with PTFE plumbers tape on the rear threads to be able to lock out similar lights, may be of help to you?

No worries.

Even better with code “BLF” (comes out to <16bux). :smiley:

Yeah, hope my order snuck through in time…

Didn’t notice any, and I think this might even be linear, because to me the slight greenish tint seems more pronounced at its lowest setting. Seems brighter almost NW on full.

Tried the jiggle test and didn’t notice anything, but nothing with a camera.

PWM doesn’t seem to bug me that much, or be that noticeable, so don’t rely on what I just said. :smiley:

Naw, it’s got a pretty good TCLO, less than a quarter-turn, almost an eighth. Just seemed to go on too quickly when first screwing on the cap, but was probably just shorting the battery to case with the spring or something. In fact, really need to snug up the tailcap to make sure it makes solid contact.

— edit —

Naw, it’s PWM. Took a lot of jiggling on its lowest possible output (before snuffing out completely), and I can see it only when doing a rather energetic jiggle side-to-side, and looking askance at the emitter.

Still, to me, it’s hardly noticeable. Ordered a 2nd one just for s&g. :smiley:

I would stay away from diving with this light or any other that runs current though the body.

On ships they place aluminum or magnesium plates on the hull to corrode before the steel hull does. Run a current from tail to head and your light will dissolve away.

Texas Shooter… what would you recommend as the best budget diving light? I’m trying hard to figure this out… at the moment the Solarstorm DX4s is at the top of my list…

I got my certification way back in the late 80's amd again in mid 90's. I've let ot all expire but when I did dive it was only with Pelican lights

Excellent dive lights, a bit costly but worth it.

Thanks for the recommendation. Had a quick look at their 3 diving lights. The output of their lights are really low, like 150-200 lumens. The plastic body is also not good for modifications… The light I buy must be a good candidate for modifications…

Here is one that I have used many times. https://www.adorama.com/pl4300by.html?gclid=CJb-i7Hx19ECFU86gQodvgIF0w

Also remember the lumen rating under water in almost total darkness will be different that dry lights. Water also magnifies light as well..

There are many great dive lights, more now than ever. I am sure better than the Pelican. The one thing I always liked most about a Pelican is none of them have ever failed. And they are guaranteed for life.

Sorry I clicked to the wrong URL when I copied it.. This is the correct one, good to 500 feet.

Thanks. Is that a diving light? They don’t specify it as being a diving light, maybe I’m missing some details?


Thanks. Is that a diving light? They don’t specify it as being a diving light, maybe I’m missing some details?

Nope you are right, I was in too much of a hurry and clicked on the wrong URL and copied it... My mistake.. Here is the correct URL and I corrected in my original post . https://www.adorama.com/pl4300by.html?gclid=CJb-i7Hx19ECFU86gQodvgIF0w

Good to 500 feet,

[quote=Terry White]

Thanks. Not that expensive though, but yes, old technology for sure. I hope to find the current best option for the Budget, Moddable (FET based driver replacement) Diving Light.


You are totally right it is old technology. Thing to keep in mind is that high current along with extreme heat, along with conductive metal in the water is a very hard thing to get just right. One of the reasons those Pelicans are still one of the best sellers.

On the other hand I am meeting some of the best and brightest here and next week you could be a millionaire from modding a dive light. I look forward to following your progress. I do not dive anymore, need to go get certified again I do miss it. But seeing your progress will be very interesting..

Terry, thanks for your feedback.

I’m a total newbie when it comes to diving lights - I know very little about the ‘gotchas’. You’re mentioning issues that I was not aware of yet. My first perception was that modding a diving light should be Awesome because one can push it too the limits without overheating problems - everything stays nice and cool in the water! I’m not yet sure how heat + high current + water causes trouble, I need to get this clarified. The other problem is the variable output switches in many of these lights. We normally cater for clicky & eswitches in the high performance drivers, so, I presume I need to pick a light that does not have a variable output switch, just a magnetic switch, which I believe reacts like an eswitch - I’m not even 100% sure about this, I need to get it confirmed.

As you can see, still lots to learn for me, I’m walking in the dark for now. But, I’m still interested to find out, as soon as possible, which budget diving lights are popular and reliable? From these, I can try to get a feel for which are mod-friendly. Thats very much what its about for me, to build an above average quality, value for money, high performance flashlight, that will last for some time to come.

Strongly doubt if I’ll become a millionaire from modding diving lights… :slight_smile:

This one only runs the current through two contacts isolated in the head Review: Acebeam D45 (XHP70 3x18650) | Candle Power Flashlight Forum Acebeam D45vn Diving & All Weather | Candle Power Flashlight Forum The slightly older D400 is still available and viable. Both heavy enough for land and water use on the D400 I’d put a rubber washer on the bottom side to insulate any current. They may be pricey, but add salt water and everything changes.

Yeh, goggle “sacrificial anode”. Even in car coolant systems, just dangle a hunk o’ Mg on a chain and it’ll get et before more critical goodies.

The critter should be insulated (anodised, ie, passivated), so ideally that should protect the body. And there should at least be some potential common to both metals, the protected one and the sacrificial one. The light itself should be a closed loop.

Maybe if the light has a bunch of starter scratches and dings, that’s where it’ll start to corrode first (like paint bubbling on a car where water gets under pinholes in the paint job).

Anyway, I ain’t gonna be using it for diving, as I don’t dive. I just got it because it looks purty, has the “infinitely adjustable” mag-switch, and is nominally at least more waterproof than the usual bunch of lights.

For actual diving, I’d imagine something sealed in plastic or rubber would be best. Also grippier when wet.

Why do you need to get “certified” to dive? Can’t just plop on all the accoutrements and fall into the water?

Or is this as a dive instructor or something?

In fresh water mostly. In salt water the heaviest anodizing won’t stop the corrosion especially when you place a current through the body. As a fancy toy light she looks good. She’ll also have much better waterproofing than most others. What I like about landlocked dive lights is that a bit more went into making them. They tend to have thicker host and heads. This is a modders dream for heat sinking.