Dive light from E-Bay -- Great buy!!!

[fmerkel]

I think the internal resistance characteristics of the battery used is still a promising lead for explaining the wide range of reported results here.

It was a bit of an over generalization but most dive lights are not high drain devices. Another generalization is that as battery size goes up, resistance goes down. A 26650 that can't support 3A is simply junk. Any DECENT 18650 should be able to.

I agree with the internal resistance (IR) idea, in theory, but I'd say the most of the people in a thread like this are still struggling with getting a decent battery, and have no tools at all to do any kind of measurement.

I have 2 analyzing chargers (Opus, and Lii-500). Both claim to be capable of measuring IR, the Li-500 is just about useless for this and the Opus is pretty inaccurate and highly variable, but it's better than nothing. It functions as kind of a rubbery stick to measure the same thing. Not great but I can compare A to B to C, or A to itself over time. That's all I use it for. When the IR gets too high the cell is certainly shot, but that also shows itself in dropped capacity and inability to support amp draw.

I'd say a high percentage of people reading this thread don't have the tools, so can't do it, and likely don't know what we are talking about, so it's not too useful in the real world. There are processes for measuring this accurately but they are complicated enough I don't bother.

 

[spoolin01]

I agree that the handful of dive lights I've tested for drain are not high drain, compared to a vaping device for instance. Most have measured around 1A, plus or minus, and that's constant regardless of battery voltage, within reason. Considering desirable run time and the capacity of the common batteries used, that makes sense to regulate them at modest drain. Dive lights not being high drain is a feature of the driver circuitry, not the LED itself, and this one lacks that circuitry.

I think the drop-in modules I used for my SL4/SL6 lights were rated up to 18V. Light output and drain was constant whether you used 4 or 6 C-Cell batteries. Try that with this light!

Since this light seems to be an unregulated single battery device, where a fully charged Li-Ion battery barely has the proper voltage to drive an LED (and different LEDs have slight differences in voltage response), and there's no boost circuitry, my guess is that the battery operating characteristics may be the reason for observed performance. High drain should imply low internal resistance, and that may make enough difference at 2-3A drain for it to show up in observed light output over time.

I recall a discussion here years ago about a digital camera that would only function with Eneloop-type batteries, not standard NiMH. Fully charged standard NiMH would soon give a low battery warning, but not the Eneloops. Same chemistry, and the capacity of the Eneloops was actually nominally less, but apparently low self discharge is synonymous with low internal resisitance, and under the considerable camera drain (1A or so), the standard batteries were operating at lower actual voltage than the Eneloops. It couldn't have been much of a voltage difference, but apparently the bad design of the regulation circuitry made it critical.

I've looked at the internal resistance feature on my Opus, but it varies so much just by re-insertion of the batteries that I concluded it was either a flawed concept or execution, or the resistance is so low that the contact-to-battery resistance confounds the results.

I think the surest approach to battery selection here is trial and error. We can hope and imagine that we can make informed choices, but so far the reports don't clearly show that.

 

[Fossil_Diver]

99% is not great feedback on ebay. Anything below 99.7% and I start checking out the feedback comments before I decide to buy. The MBG us excellent but can be a hassle so I try to avoid problems.

 

[TulsaTime]

For those not wanting to get into the nitty gritty of battery and/or charger testing themselves, I found this site invaluable in my search for a charger and reliable batteries:

Welcome to my page about batteries, chargers and flashlights​

This guy does extensive testing of chargers with full details about his testing methodology. Take a look at any of his reviews and you'll find enough testing results data and charts to make your head swim.

Based on his reviews and other comments/research from this thread, I ended up with the following:

• LG 18650MJ1 Protected 3500mAh from Mountain Electronics
  
• 26650 KeepPower 5200mAh Protected High Discharge Flat Top from Illumn
  
• Enova GYRFALCON ALL-88 8x Li-Ion + NiMH Charger from Mountain Electronics
  
• D26 XM-L2 LED Diving Flashlight Set from XTAR Direct

The 18650's are for a video light that I already owned.

As yet I've only used these for a half dozen dives but so far I'm pleased with them all.

Also, while putting this post together, I noticed that Illumn has the 26650's on sale for $8. That's a great price since they're normally $13.99 (which is what I paid).

 

[stuartv]

• 26650 KeepPower 5200mAh Protected High Discharge Flat Top from Illumn
  
• Enova GYRFALCON ALL-88 8x Li-Ion + NiMH Charger from Mountain Electronics
  
• D26 XM-L2 LED Diving Flashlight Set from XTAR Direct

That is a good price for the 26650s, but the Soshines I got on eBay were even less, and they all tested out between 5200 and 5300 mAh.

The Gyrfalcon charger looks awesome! That's the first charger I've seen that can charge more than 2 26650s at a time. And it can charge 8 at once!

The Xtar D26 is my current favorite light. <$60 on eBay and I like it significantly better than my DGX 600 lights. The D26 is very slightly brighter (in Turbo mode) but otherwise pretty similar beams, but the other features and much longer burn times on the D26 are The Shiznit! Maybe some day I'll start diving caves, and then do that enough to start diving caves with stages. At that point, I guess I would probably need to buy a can light. Until then, the D26 seems to give me everything I personally need from a primary light. And in a really nice compact size.

Thanks for posting those links!

 

[FiddlerOnTheRoof]

WOW I can't believe my thread got up to 30 pages.. That's cool!!

Just wanted to let you all know I still have the 2 lights I originally purchased and posted about here and they are still working great for me.
I've had them both to over 150 feet and 100+ dives.

Peter

 

[TulsaTime]

That is a good price for the 26650s, but the Soshines I got on eBay were even less, and they all tested out between 5200 and 5300 mAh.

I was in a hurry to get all this and so limited my search to US-based storefronts. I needed to get it all in hand quickly so I could try it out locally before going on my first LOB in less than two weeks now (and yes, I'm very excited - just about worthless at work!)

The Gyrfalcon charger looks awesome! That's the first charger I've seen that can charge more than 2 26650s at a time. And it can charge 8 at once!

It doesn't have the discharge/analytical testing of, for example, your Opus but it can do 8 bays at 1A and each bay is independent. It also handles LiFePO4 batteries which is what my Lynx uses. It doesn't do any kind of automatic recognition of battery types though so it does require you to know something about the batteries you're charging (charge voltage and current).

The Xtar D26 is my current favorite light. <$60 on eBay and I like it significantly better than my DGX 600 lights.

Your recommendation is what led me to this one and I'm with you - I like this light. My opinion shouldn't necessarily carry much weight here though since I don't really have any experience with other lights to compare against. The only thing I'm not crazy about with this light is the locking switch - it's a little difficult to rotate into and out of locking position, especially underwater. I think it'd be nearly impossible with any kind of gloves on. If the switch was just a little taller, it'd be ideal. Of course, the fact that it has a locking position at all is still a big positive.

One thing I would point out though - If you look at the "warranty" card that comes from the manufacturer, it's 15 DAYS. However, if you buy it from XTAR Direct, they offer a 30-day replacement, 24-month free repair, and limited lifetime warranty. So, while you can find it cheaper on eBay, for some (like me) the warranty and support from XTAR Direct may be worth the premium. For others, the lower cost may justify a "just toss it if it breaks" approach.

I'd also recommend going with the kit as opposed to just the light itself. For just another $20, you get a plastic carrying case (cheap and definitely not waterproof but it does keep things organized), an XTAR single-cell charger, and an XTAR branded 5000mAh 26650 battery.

Thanks for posting those links!

Thank YOU for your posts! Like I said, your recommendation is what led me to the D26 in the first place. I also heavily used your battery and charger recommendations in my deliberation process.

 

[oldschoolto]

My 4 lights are all working great and about 75 dives... 2 of the lights have been to 165'... No leaks...

Jim...

Edit to add... I like them so much, I keep one next to my bed... Use it when the power goes out.. Or need to go out at night...

 

[fmerkel]

For people interested in the Xtar d26, or any Xtar battery or charger they have a 20% off sale right now, ending Aug. 31.
Coupon XTAR20.

If you are one that likes this: [However, if you buy it from XTAR Direct, they offer a 30-day replacement, 24-month free repair, and limited lifetime warranty. So, while you can find it cheaper on eBay, for some (like me) the warranty and support from XTAR Direct may be worth the premium. For others, the lower cost may justify a "just toss it if it breaks" approach.]
then the deal might appeal to you.

IMO Xtar puts out some superior products. They have good easy to use chargers that you can trust.

 

[stuartv]

For people interested in the Xtar d26, or any Xtar battery or charger they have a 20% off sale right now, ending Aug. 31.
Coupon XTAR20.

Nice! I really would like to get one of their D35 lights. 3 of the same LEDs that are in the D26. 3 x 18650 batteries. Compact (relatively) and still with a runtime on High that should be comparable to a DGX 600 - only with more light.

But, $160 WITH the coupon! Better than $200 without, but, still, ouch! I just can't justify it. That's getting into the territory, price-wise, of one of the Brinyte or similar can lights.

OTOH, I couldn't resist $64 for another D26, with a lifetime warranty. Having 2 just seems like a good idea.