Newbie questions re: CREE products and batteries

cyclesport

Enlightened
Joined
Feb 14, 2012
Messages
676
Hi All…
Relatively new to flashalcoholism but have a few question Iwas hoping someone could answer for me.
· Is there one source somewhere that gives the genesisof CREE flashlight LED models (XPG-R5, XML-T6, etc.) up to the present startingwhen these products first came to the consumer market.
· I notice there are many quality productionmanufacturers producing flashlights utilizing two cell CR123's or one 18650 thatproduce, or claim to produce, anywhere from a little over 400 lumens with someover 700 lumens? Why the disparity with the same power source?
· And lastly, for common EDC lights that can use18650 Li-ion cells…what should I use button-top or flat, protected or unprotected, and what outputratings, etc.?
Any help would be appreciated…Thanks!

cyclesport

 

yifu

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Joined
Oct 15, 2011
Messages
713
Location
Australia
Well Cree is just one of several large LED manufacturing companies which include Seoul SSC, Philips Luxeon, Nichia and Luminous Devices etc. They are however leading the industry in terms of efficiency. The development path for power LEDs started with the XR-E 7090 in 2007, the P4 bin was the first LED to output in excess of 100 lumens. This later developed into the XP-E line (where the package size was reduced), the XP-G line (where the LED substrate size was increased but the package size remained constant) and finally the XM-L product, which had double the die area of the XP-G and produced around 970 lumens at 3A (can be overdriven) and around 167 lumens/watt at 700mA drive current. There are obviously many derivates like the XR-C, the XP-C, the high voltage LEDs etc but the 4 i talked about are the main Cree LEDs used in flashlights.
To answer your second questions, different flashlight manufacturers tend to vary their drive current for reasons such as efficiency, runtime and thermal issues, so you get anywhere from 200 lumens to over 1700 lumens on ONE 18650. I am talking about out the front lumens by the way.
Button top vs flat is not a matter of preference but rather based on the design of the light it is going to be used in, if there is a spring at the top, flat top cells can be used. AW, Redilast, Kallies' Kustoms are some of the best protected 18650s you can find. I recommend the 3100maH variant although IMR cells of the 2250maH variety are better suited for high current applications where the discharge rate exceeds 2C(6.2A for the 3100maH). There are of course the OEM sanyo/panasonic/samsung 18650 cells that you can get. They are very good but lack the protection circuits.
Hope that helps. There is a daunting amount of information in this hobby and in time your interests will no doubt shift towards things like customs, HIDs, short arcs, aspherics and you'll learn more!

Don't let my join date fool you! I've been around for wayyy longer than 6 months, it's just i lost my password and after the Great CPF crash of 2011 somehow couldn't recover my old account.
 
Last edited:

cyclesport

Enlightened
Joined
Feb 14, 2012
Messages
676
Well Cree is just one of several large LED manufacturing companies which include Seoul SSC, Philips Luxeon, Nichia and Luminous Devices etc. They are however leading the industry in terms of efficiency. The development path for power LEDs started with the XR-E 7090 in 2007, the P4 bin was the first LED to output in excess of 100 lumens. This later developed into the XP-E line (where the package size was reduced), the XP-G line (where the LED substrate size was increased but the package size remained constant) and finally the XM-L product, which had double the die area of the XP-G and produced around 970 lumens at 3A (can be overdriven) and around 167 lumens/watt at 700mA drive current. There are obviously many derivates like the XR-C, the XP-C, the high voltage LEDs etc but the 4 i talked about are the main Cree LEDs used in flashlights.
To answer your second questions, different flashlight manufacturers tend to vary their drive current for reasons such as efficiency, runtime and thermal issues, so you get anywhere from 200 lumens to over 1700 lumens on ONE 18650. I am talking about out the front lumens by the way.
Button top vs flat is not a matter of preference but rather based on the design of the light it is going to be used in, if there is a spring at the top, flat top cells can be used. AW, Redilast, Kallies' Kustoms are some of the best protected 18650s you can find. I recommend the 3100maH variant although IMR cells of the 2250maH variety are better suited for high current applications where the discharge rate exceeds 2C(6.2A for the 3100maH). There are of course the OEM sanyo/panasonic/samsung 18650 cells that you can get. They are very good but lack the protection circuits.
Hope that helps. There is a daunting amount of information in this hobby and in time your interests will no doubt shift towards things like customs, HIDs, short arcs, aspherics and you'll learn more!

Don't let my join date fool you! I've been around for wayyy longer than 6 months, it's just i lost my password and after the Great CPF crash of 2011 somehow couldn't recover my old account.
 

cyclesport

Enlightened
Joined
Feb 14, 2012
Messages
676
I did indeed DM51...just wanted to thank yifu for the detailed answers, very helpful! Thanks for the welcome as well and I'm really learning a lot reading the posts from the many knowledgeable people contributing here...Thanks again.
 
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