Ultrafire DV-S9 diving light?

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Lightbringer
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Pete7874 wrote:
From Ultrafire’s website for this DV-S9 light:
Quote:
Power Supply: 1*18650

Current: 3800mA

Runtime: 4 Hours


Hmm…. something does not add up here. Smile

Anyway, do you have any beam shots?

Naw. One of the websites had nonsense descriptions, like “switch: clicky”, “modes: h/m/l/SOS”, etc.

Ah, here ya go! Right from the horse’s ass, umm, mouth:

http://www.ultrafire.com/index.php?route=product/product&product_id=8428

 

Number of Modes: 3

Mode Arrangement: Hi,Low,Slow Strobe

 

Whaaaat??

Methinks lots of these “specs” are just c&p from other lights, and no one bothers to even look at them half the time.

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Jerommel
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texas shooter wrote:
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.

I doubt that’s because of electrical current.
The shell is (usually) negative and there’s no positive outside, so there’s no current through the water surrounding the body.

Looking for:

5” parabolic reflector (for recoil light)

Jerommel
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Let me rephrase:
There is current through the battery tube from tail to head.
But since the battery tube has very very low electrical resistance, there’s hardly any voltage between tail and head, so i expect electrolyses is negligible or just not happening.

The picture shows problems on the edges.
Probably damaged anodization, and so the seawater just has a go with the aluminium.
The result is porous salts which absorb seawater so that the process continues on dry land.

Looking for:

5” parabolic reflector (for recoil light)

kramer5150
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Jerommel wrote:
texas shooter wrote:
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.

I doubt that’s because of electrical current.
The shell is (usually) negative and there’s no positive outside, so there’s no current through the water surrounding the body.

Those pics are from a 2012 thread. The damage you see is from galvanic corrosion and electrolysis when this light is submerged in salt water. Basically it forms a cathode / anode and the salt water is the electrolytic solution. It only happens when this light is turned OFF (IIRC) though because the electrical circuit when turned on becomes the current path of least resistance. The condition is worsened for spots where the anodize is scratched off or etched off. Thread here… skip ahead to page 5-7. IIRC a couple different members were complaining about the same thing.

http://budgetlightforum.com/node/11143

See post 178 and 191….

Lightbringer
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kramer5150 wrote:
Those pics are from a 2012 thread. The damage you see is from galvanic corrosion and electrolysis when this light is submerged in salt water. Basically it forms a cathode / anode and the salt water is the electrolytic solution. It only happens when this light is turned OFF (IIRC) though because the electrical circuit when turned on becomes the current path of least resistance. The condition is worsened for spots where the anodize is scratched off or etched off. Thread here… skip ahead to page 5-7. IIRC a couple different members were complaining about the same thing.

http://budgetlightforum.com/node/11143

See post 178 and 191….

Good read, and answers some questions I had about all this.

Specifically, even with a decent tailcap switch, if it’s tightly connected to the body, the only breakpoint is between the internal switch and the (-) end of the cell. The whoooooole head+body+tailcap should be one long electrically-conductive piece, all at 0 potential. So like a shielded cable, the entire length would be one long 0.

And unless you turn your flashlight into an electron-gun, it’s only 1 electrode in a salt-bath, and no fizzing should occur.

That’s why, a design like this one, no switch in the tailcap, screwed on tightly, no reason to twist/untwist anything, and a magnetic slider, nothing should make a 2nd connection/electrode. (Think of way bigger version of an Astrolux A01 1-piece body, only no twist-head, but one solid piece, internals (incl. battery) accessible only through the front bezel and lens, and an internal magnetic switch.)

That’s why, in the shown pix, what’s fizzing off of what. If it’s a 2-electrode system bathed in saltwater, 1 set of bubbles should be H2 and the other set should be O2.

Lookit https://en.wikipedia.org/wiki/Electrolysis_of_water . The (-) end should fizz H2, and the (+) end should fizz O2.

By figuring out which is which, you can narrow down where’s the break in continuity, and see what can be done to fix it.

Point being, in a good solid conductor, there should be no fizzing of any kind no matter how much current is going through it, not unless the voltage drop is more than 1.23V.

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EndlessWaves
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Lightbringer wrote:
mikeyx wrote:
Looks similar to the Starry Light DXM.

Ha… twins! Big Smile

I was wondering if there were any “relatives” of this light floating around out there. Now I know!

There’s also at least one more version that’s sold under various names that has the Starry Light DXM tailcap and simple spiral knurling. Here’s a (fake?) ultrafire-branded version:
https://www.fasttech.com/products/1601/10010861/4516600-ultrafire-cree-x...
It’s also around in black and green variants:
www.amazon.co.uk/d/s7v/Flashlight-Underwater-Waterproof-Torch-Submarine-...

There’s also the Ultrafire UF-S11 which looks like it might be a slightly more distant relative as it has similar proportions and a magnetic switch. Although it seems to consistently claim 3 modes instead of being infinitely variable:
http://www.gearbest.com/led-flashlights/pp_576215.html

Back to the DV-S9. Does it take protected batteries and what is the beam spread like? Similar to the Starry Light DXM? How hot does it get if left along on maximum brightness?

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EndlessWaves wrote:
Back to the DV-S9. Does it take protected batteries and what is the beam spread like? Similar to the Starry Light DXM? How hot does it get if left along on maximum brightness?

Interesting clones, cousins, whatever. Big Smile

Yeah, I got a protected 26650 that fits just fine. Big honkin’ springs on each end, so could probably take a ¼” spacer, too, and still fit.

Beam’s nice, pretty well-defined hotspot, decent spill, maybe the size of an XM-L in a C8. Wider than an XP-L HI C8, narrower than my (stock) VG10.

Bulb above my washing machine went out, had the DV-S9 tailstanding on full, using ceiling-bounce for light. Had it going about 10min straight, comfortably warm, nowhere near hot. It’s got a good amount of bulk to it.

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Van
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texas shooter wrote:
As long as current is past through the body it wouldn't help. Current has to be isolated from all external parts. At 8.4 volts 3 amps you could probable see gas bubbles forming if done in still water like a fish tank. Simply having both contacts at the head and none of this would happen.

Since the body of this DV-S9 is made to use both 18650/26650, when using 18650 there should be ample space left on the sides, right?

Maybe it is possible to disconnect the body contacts and make one's own wire connections going alongside the 18650 battery to the head?

Jerommel
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kramer5150 wrote:

Those pics are from a 2012 thread. The damage you see is from galvanic corrosion and electrolysis when this light is submerged in salt water. Basically it forms a cathode / anode and the salt water is the electrolytic solution. It only happens when this light is turned OFF (IIRC) though because the electrical circuit when turned on becomes the current path of least resistance. The condition is worsened for spots where the anodize is scratched off or etched off. Thread here… skip ahead to page 5-7. IIRC a couple different members were complaining about the same thing.

Aha, it has a tailcap that acts as a twisty switch. I didn’t know that.
So, when it’s turned ‘OFF’ there’s the battery voltage between tailcap and body, and then electrolyses will happen.

Looking for:

5” parabolic reflector (for recoil light)

Jerommel
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I see i forgot to ask how the PWM is.
I assume they use PWM, and i know the big XHP70 diving lights with stepless slider is quite noisy (but not visible).
So how’s this one doing?
I like the concept.

Looking for:

5” parabolic reflector (for recoil light)

Lightbringer
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Jerommel wrote:
I see i forgot to ask how the PWM is. I assume they use PWM, and i know the big XHP70 diving lights with stepless slider is quite noisy (but not visible). So how’s this one doing?

The DV-S9?

Think I mentioned it early on. My phone’s camera can see it, but honest to B’Harni (pbuh!), I can’t see it.

Didn’t take it into the shower or in the rain, but even flicking the light back’n‘forth across the room, I don’t notice anything.

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flydiver
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To revive an older thread….

Just received one of these. Looks decent to visual inspection and has survived a simple dunk+burn test. It has a low voltage cut-off and the light goes out suddenly and entirely with the battery showing ~3.2v after. It will not restart, even on low.
Light is a diffused focus similar in intensity and spread to my regular canister (4 LED, 2S2P 18650) dive light. Light intensity seems to stay decent down to cut-off.

I LIKE that the switch mechanism seems to be internal with just an external slider. First slider light I’ve had. I like it so far.
A bunch of the cheap dive lights with Hall sensors have external magnetic mechanisms with springs/magnets/occasionally ball bearings that are cheap steel and rust to garbage with saltwater use. They would be OK for shore use but are completely unsuitable for actual diving. Saltwater is death on them after awhile.
The 3xO-rings are good and seem to seal well. Hopefully the lens sealing mechanism is decent. It appears to be a single silicone O-ring which is typical of this price point.

I will be taking it for an empty test dive. If it survives I’ll put a battery in it and do a dive test. Then we’ll see if it can pass as a dive light. Big Smile

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That was my only question, as to whether/not the front glass is adequately sealed against water ingress with the single O-ring in front.

I don’t go diving (I’m allergic to drowning), so can’t really put it to the test. Big Smile

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flydiver
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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…… Facepalm

flydiver
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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.

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