Ultrafire DV-S9 diving light?

Single O-ring is completely sufficient to seal……IF the design and execution are good. I carry a $800 camera+lens on dives that has a dozen small single O-rings sealing controls, one large one for the lens port, and a huge one for the camera housing back. They all work just fine if clean and in good shape.

The problem with cheap lights is often poor design, shoddy assembly, and/or lousy parts. That’s what I’m checking out here.
Then there is the operator factor…… :person_facepalming:

Took it for a single dive, saltwater, 56 feet max depth, about an hour exposure. No flooding, no sign of electrolysis. Day dive with decent ambient light so not optimal for evaluating the beam. It’s not as bright as my canister light, but it’s not bad. Would seem suitable for tropical use and as a backup light to a primary, even a primary for an occasional diver. Lasts over 3 hours with a 5000mA, 26650 in it (bench test). I got tired of watching it and it quit sometime after that, 3.24v remaining in the battery.

Yeah, I don’t recall what I measured way back when, but I don’t think it was more than 1.5A running wide-open.

Just ordered up the U`King ZQ-X960 CREE XM-L2 1200LM Underwater 100m Diving Flashlight Torch - BLACK

Seems to be almost the same light, minus 1 sealing O-ring, + a better end cap for a lanyard, which means it won’t end stand but for a “real” dive light this is not important.
Starry light DXM seems to be no longer available on GB.

Received the U’King light. In black it’s a bit more traditional looking. I did a quick run test in a glass of water and it came out dry. Then did a long run test using a Lii 5000mA > 4+ hours before it shut down.
One less sealing O-ring but I thinks that’s because the assemblers of the DV-S9 (mine anyway) put an ’extra one in the grooves behind the grooves machined for that. There is an adequate space and it doesn’t hurt anything. I may add one myself. Can’t get too much sealing for real diving. :stuck_out_tongue:
Slider is a bit stickier even after greasing. Did not realize the ring behind the slider unscrews and the slider can come out.
Light intensity and spot seem identical to DV-S9.
Dive test pending, probably after the holidays.

I’m finding the green tint seriously ugly, otherwise it’s a great light. Mine doesn’t come on until I’ve screwed the tail cap on REALLY tight.

It seems that it would really benefit from an emitter swap, but from what has been posted it sounds as if it might be difficult to get at the interiors.

Not got the necessary skills to reflow an LED yet, but if there’s a way to get behind the lens without compromising the sealing, it would be something I’d be interested in at some point in the future.

Green? You referring to the Ultrafire or UKing?

Mine’s definitely on the cooler side of CW, at least 6500K, but doesn’t have even a hint of green.

And I hate green-tinted beams…

Chances are the front ring unscrews. No idea if it’s glued. That will press down on the glass lens and there will be an O-ring, probably silicone, under that. After that it should be fair normal but the pill will have a Hall sensor on it. Getting it back together dive level water tight is another issue. Splash tight should be a snap.

I don’t have any issue with the tint. No green to me on either light. Maybe you got a poor bin. But color goes away fast underwater anyway, with reds going within about 15-20 feet, and working it’s way through the rainbow spectrum with depth. In the NW we have so much plankton in the water everything is pretty green all the time anyway no matter the depth. We just need lots of light.

I was referring to the DV-9. Compared with my other lights the beam definitely has a rather sickly greenish tint - will try to take some photos and post a vomparison.

Yes, I guess when it is actually used for diving, the tint won’t really matter too much. Not been scuba diving for nearly 30 years, but I do remember how red colours fade very quickly after a few meters.

Just dug out mine again. Got 3, all the same tint, white-white ever so slightly on the blue side. Not a hint of green, even at moonlight levels.

My 2AA-X? Green. Jet-I? Green. F1? Green.

DV-S9? Not a trace of green.

Yeah, you may’ve lost the tint-lottery.

Maybe they added AR-coated glass to green it up?

Pretty sure it’s not AR coated.

Last time I used it a few weeks ago, I forgot to turn it off, and I noticed the next day when the light was very dim. But instead of taking the battery out (VTC6 with sleeve), I left it inside, and I just noticed it has been drained to 2.31V! Currently charging the battery and obviously checking the temperature every few minutes - that should be safe as long as I keep an eye on it, right?

That’s kind of low but it should live. Mark it and watch it for heating or other bad behavior.

One of the things I really liked about the DS-V9 I had (gifted away), was that it had what seemed to be a reliable low voltage cut-off @ 3.25v (resting and tested after pulling it out). The U’King is the same, at least the 3x I’ve tried it. Sounds like maybe you have a ‘lemon’ (lime? :wink: light.

I’ve resurrected some laptop pulls from lower. :smiley:

I use them only in lights where I can keep an eye on them, not as nightstand lights or anything. No problems yet.

I also try to never run them down too low. Only once did I notice a light get dim (S2+) and then blink itself silly. Immediately turned it off (before it turned itself off) and recharged the cell. Didn’t measure its voltage.

I’m pretty sure that the LVP didn’t kick in - unfortunately I didn’t check the battery level before I turned it off, but it must have been way below 3.25V, considering how dim it was. And it would be an insane parasitic drain, if the battery had been depleted by one volt in just a couple of weeks - I thought only Nitecore lights did that!

Does that mean it could still cause problems during use after successfully recharging it? I thought the only issue was the charging process after a battery has been drained to <2.5V?

10mA as I measured mine. About as much as a single LED on moonlight mode.

What about if LVP kicked in, turned off the light, but that 10mA kept draining it all the while you forgot about it?

Parasitic drain is parasitic drain, period. Keeps the Hall-effect sensor alive, powers the µC, etc., just turns off the power to the main LED. That’s pretty much the same for all lights without a mechanical off-switch. All e-switch lights, all sliders, etc.

Meant that I’ve been using my resurrected pulls for quite a while without incident.

There may be parasitic drain after the light goes out. Since yours was still on there certainly was drain. Once the battery is significantly drained it doesn’t take much to pull the voltage down lower. Mine stays fairly bright and simply goes out….gone. It will not start again. I have not left it that way so don’t know what happens if that is done.

On over discharge there is the potential for permanent damage. Depends on the battery quality, age, and degree of discharge so there is no clear answer. Seems 3.0v is pretty safe, 2.8v is OK, 2.5v IMO is pushing it but not a catastrophe. Once you get down below 2.0v it’s not so good. Then you get into the whole debate of what’s the battery worth to you vs. the potential for damage and harm?

The problem does generally show up with charging, but there are reports of problems during use. But the specifics of those are often difficult to clearly determine. I’ve got some lipos (for RC flying), that were new and I accidentally discharged to 0v. I ‘boosted’ them with a NiXX charger, and then charged them normally. They puffed a bit but continued to operate like normal 2 years later. They ARE marked, kept in a fridge at storage charge, and ONLY charged just before flying. Obviously I didn’t toss them, but I SURE AM watching them.

Thanks for the infos. Will definitely be marking it, and using it for low-risk applications.

I usually recharge my batteries when they reach about 3.6V - I hate the thought of walking my dog, and not being able to use turbo mode, since most of the lights that I own draw a high current and cause a considerable voltage sag. That’s why I have plenty of VTC6 and 30Q lying around and I used one for the DV-9, otherwise a high drain battery would probably be overkill for this light. The one that I used had been recharged less than ten times.

With nightstand lights, I’ve been testing how long they last in the lowest mode. But after this experience I’ll probably put an end to that, and check the voltage more regularly. Or I’ll just use my Olight S Mini with CR123A - those cells almost seem to last forever! :slight_smile:

I’ve got some low capacity ‘junk’ cells. I use those for testing unknown situations. Not of much use for high draw applications but work OK for other stuff.

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

I just unscrew a few threads , and no drain.

¼-turn is usually enough to break contact, and not engage if you squeeze it together, but I give it about ½-turn to be sure.