Alternatives to Dive Rite LX 20

[Caveeagle]

Aren't both of those Hollis lights twist-on? I don't know of any Hollis lights with a push button.

I have three them sitting right in front of me. got two LED-3 and a LED Mini3 to try out as back-ups and primaries for my kids to use cavern diving. (purchased about a yea ago).

 

[tbone1004]

Maybe. But, the XHP50 efficiency is only 149 lumens/Watt. The XM-L2 is 170. So, if you're talking about a handheld light with 1 x 26650 or 1 x 18650, the only way I can see the XHP50 being brighter is if you are willing to live with a MUCH shorter burn time. And I'm pretty sure the Deep6 light is not using that.

The XM-L2 is using 6W to put out 1000 lumens (at 170lm/W). For the XHP50 to put out the same, it would be burning almost 7W. So, a 90 minute burn time would drop to less than 80? And if you actually wanted the XHP50 to put out 2000 lumens, it would be less than 40 minutes burn time (assuming the same battery that gives 90 minutes with an XM-L2)?

You could build a more compact light head to produce the same amount of light, but otherwise, I don't see the advantage of the XHP50. Can't you get the same light with 3 x XM-L2 and have better burn time? (at the expense of a bigger light head)

I'm also looking forward to what's coming out with using the newer tech COB LED arrays - especially for video lights.

I'm with @victorzamora the 170l/w is not real, but more importantly with efficiency drops from the drivers and emitters, you aren't going to see those kinds of efficiencies out of any of these asian lights.

the XML lights are not capable of burning at their full brightness for 90 minutes on a single 18650. Let's do some napkin math, which means assuming 100% efficiencies and utilization. The top end 18650's will have 12.6wh, those are the high end Panasonics with 3.4ah. To get 1000 lumen which is what they're rated at, and assuming 120l/w which is generous, they'll be pulling 8.5w of power. Theoretically, you could get 90 minutes at 1000 lumen out of that. Realistically you'll be lucky to get 90% efficiency out of there, and you are only probably going to get 90% of that battery so that's about 70 minutes of real burn time if it burns at full power.

 

[stuartv]

That's all fine and dandy about real world efficiency versus specifications for "max", but doesn't the same thing apply to the XHP50? So, comparing specs for efficiency is not legit? The XHP50 spec is lower efficiency than the XM-L2.

As @victorzamora noted, the efficiency might be different at different output levels. So, does the XHP50 actually have better efficiency than the XM-L2 when it's putting out 1000 lumens? At 2000 lumens? If so, then sure, you would be able to build a light that puts out the same lumens for the same or longer burn time. Or more lumens for the same burn time.

Do either of you know? I do recognize that that could TOTALLY be the case. I'm just curious if there is actual data available to support this idea, or if we are just speculating.

 

[victorzamora]

I have three them sitting right in front of me. got two LED-3 and a LED Mini3 to try out as back-ups and primaries for my kids to use cavern diving. (purchased about a yea ago).

That's super strange. I've got a few of the LED Mini3s at the house and they're all twist-on. I had but sold LED5s and LED3s...but they're all at least 4-5 years old at this point. Maybe Hollis changed them?

 

[stuartv]

That's super strange. I've got a few of the LED Mini3s at the house and they're all twist-on. I had but sold LED5s and LED3s...but they're all at least 4-5 years old at this point. Maybe Hollis changed them?

"Maybe"??

Just teasing you, man.

 

[victorzamora]

Cree XLamp XM-L2 LEDs

And, yes, I know the XHP50 is rated for a max of over 2500 lumens.

Cree XLamp XHP50 LED

From that top link:

The XM-L2 LED offers the unique combination of high efficacy and high lumen output at high drive currents, delivering an unprecedented 1198 lumens at 116 lumens-per-watt efficacy at 3 A, 25°C.

From your second link:

At its maximum current, the XHP50 LED delivers twice the light output of the industry’s brightest single-die LED, the XLamp XM-L2 LED, at a similar lumens per watt and without increasing the package footprint.

That's all fine and dandy about real world efficiency versus specifications for "max", but doesn't the same thing apply to the XHP50? So, comparing specs for efficiency is not legit? The XHP50 spec is lower efficiency than the XM-L2.

As @victorzamora noted, the efficiency might be different at different output levels. So, does the XHP50 actually have better efficiency than the XM-L2 when it's putting out 1000 lumens? At 2000 lumens? If so, then sure, you would be able to build a light that puts out the same lumens for the same or longer burn time. Or more lumens for the same burn time.

Do either of you know? I do recognize that that could TOTALLY be the case. I'm just curious if there is actual data available to support this idea, or if we are just speculating.

So, to answer your final question: Do I know? Yes, I do. The XHP-50 has a similar efficiency at its absolute max limit as the XM-L2 does. So, when it's driven back down to the middle of its range, it's more efficient. The TDS shows those curves, and I'm too lazy/busy to dig through them at the moment. So, yes, the XHP-50 is a better emitter than even the XM-L2 (and notably better than the XM-L)....but I doubt it's necessary in a backup light (assuming costs are higher).

 

[Caveeagle]

That's super strange. I've got a few of the LED Mini3s at the house and they're all twist-on. I had but sold LED5s and LED3s...but they're all at least 4-5 years old at this point. Maybe Hollis changed them?

Part # 206-3050-M (mini-3) and 206-3060-M (LED 3)

 

[stuartv]

The top link specs chart says 170. I didn't read the text that says 116.

Anyway, I don't need you to dig up the docs. If you say you've seen it, I believe you. I was just look at the specs in the chart.

If the XHP50 is more efficient than the XM-L2, when putting out 1000 lumens, I think it would be nice to have in a handheld, just for the potential for longer burn time with the same amount of light. And maybe the ability to crank it up on High when you need to. And/or make a light that uses an 18650 and is the size of the DGX600, but is as bright and burns as long as the Xtar D26.

 

[victorzamora]

Part # 206-3050-M (mini-3) and 206-3060-M (LED 3)

Well THAT blew my mind! Mine are all twist-on. The Hollis manual and site only mentions twist-on. But sure enough, they have a push button: Hollis LED 3 mini light

It sucks to hear that they stick, though. It looks like a nice button.

 

[victorzamora]

The top link specs chart says 170. I didn't read the text that says 116.

Anyway, I don't need you to dig up the docs. If you say you've seen it, I believe you. I was just look at the specs in the chart.

If the XHP50 is more efficient than the XM-L2, when putting out 1000 lumens, I think it would be nice to have in a handheld, just for the potential for longer burn time with the same amount of light. And maybe the ability to crank it up on High when you need to. And/or make a light that uses an 18650 and is the size of the DGX600, but is as bright and burns as long as the Xtar D26.

I agree it'd be nice to see an XHP50 in a handheld/backup....but pricing will drive that and I don't really have any insight there. One thing to mention, however, is I can't imagine it being much more efficient (5-10%, maybe) than the XM-L2. The burn time on an XHP/18650 simply won't be as high as an XM-L2/26650 combo. Even good 18650s only get to ~3400mAh which is still only 62% of the capacity of a 26650. Using rough math, the XHP50/18650 should burn ~65-75% as long with the same light output as the D26.