Which drop-in is more efficent?

Gary, thanks for this link.. I havent seen that before! very useful!!!

I presumed that they stated 800ma for the 5xR2 drop-in, thats why I said 4A.

Here is the link to the efficiency of each emitter the T6 wins.

http://flashlight-wiki.com/Brightness_Bins

Some useful info at this link as well (1st post): http://club.dealextreme.com/forums/Forums.dx/threadid.747581. Guess I wasn't understanding where the current draw is being measured. So it really is "per LED" I take it.

Now I know I said throw vs. spill didn't matter, but any ideas? Would the 6x Q5 or 5x R2 or single XM-L module produce more flood (spill)? Do people generally go with multiple LED's to get flood? I know reflector plays into this a lot, but just go with these particular modules.

Thanks,
Garry

are u trying to compare multiple leds with single??

Garry, the most efficient drop-in you can probably make would be a true voltage regulated driver at 1.4A feeding an T6 XM-L. Use a driver like the Nanjg 101 AK with 4*AMC7135 chips. You will have plenty of output (500-600 lumen) and the best battery life.

the best is to buy both.. and you will find the answer

I would recommend this also...

Wondering, has anyone made only 1000mA dropin with XM-L?

So, is it possible that I could replace the driver with a 1.4amp or less (ie. 1.0amp) and drive this XM-L drop-in from 2 D sized Alkalines? This would be ideal for me. Common size battery, yet large D size for runtime. +/- 400 Lumens sounds like plenty of light.

Thoughts?

Garry

How about this driver? http://www.kaidomain.com/product/details.S009113 . Says 0.9v - 4.2v 1000mA boost and buck current regulated 17mm diameter. Would this be compatible with the Dealextreme XM-L drop-in and 2 alkalines? Would the voltage cutoff of 2.75v cut off the alkalines too early?

New to the driver scene.

Garry

Might not be of interest any more, but here are some data on the 5*XR-E R2 and 6*XR-E Q5 drop-ins running on 2*18650:

5*R2: light output: 820 - throw: 330m - unfortunately I didn't measure the current.

6*Q5: light output: 850 - throw: 300m - 1.85A

Light output in arbitrary units (roughly mimicking lumens) measured via ceiling bounce.

How about the above mentioned driver running 3 alkalines? It says max 4.2v input and the alkalines would be 4.5 though. Seems with alkaline C's or D's I should stay at about 1amp max. Not sure what kind of runtime this would provide. Any ideas?

Garry

It's sold out for a very very long time now.

alkalines, seriously? that makes turning the light on cost alot....atleast look at rechargables.

Personally I'd love a light running on 2 or 3 d cell rechargeables, capable of 500 lumens for a couple of hours.

The extra width of the battery tube would mean a larger head wouldn't look quite as odd.

Ok, missed it being out-of-stock. How about a driver from elsewhere? DX, since that's where the drop-in is coming from? Which way would be more efficient - 2 D cell Alkalines? or 3 C cell alkalines?

What I am getting at is a "simple" 2D Maglite XM-L with good runtime. I don't need the "WOW" factor out of this light. Allowing it to be run on simple everyday alkalines is a plus. Would consider rechargables (NiMh), however that is additional cost (both cells & a charger). At least I could start on alkalines and move on to NiMh cells later.

Garry

Garry

Good efficient boost drivers (under 3.7 V) are hard to find nowadays, especially multi-mode ones.

Maybe you want to take a look at the good driver list.

Just looked at the original list and its got 40k views! Not half bad, IMO xD

Great work on Brteds end of keeping it updated and expanded : )

If you are to compare emitters you need to look at each individual emittor and the percentage of the rated output they are each giving versus there total input current.

Here is what we have

XML--> 850 lumen at 3A and 3.3V = 9.9W = 850 lumen at 86 lumen per watt

5x XP-G R5--> 350 lumen at 1A and 3.35V each = 3.35W = 1750 lumen at 104 Lumen per watt (x5 = 16.75W total)

6x XR-E Q5--> 1200/6= 200 lumen at 0.8A and 3.5V each = 2.8W (each) = 71 lumen per watt. (x6 = 16.8W total)

Unless Driven at very low currents (in which case the XML will rule at 159 lumen per watt) the XP-G is the one you want. If you could find a triple XML it may well be a different story

Please note this does not account for the drivers and other inefficiencies, only the power at the LED if supplied at the voltages and currents given. All information comes from the relevant Cree datasheets and the DealExtreme website (for driving current).

Thanks for that info!

Garry

The forward voltage of the XP-G R5 is 3.3V @ 1000mA according to CREE's official data sheet. http://www.cree.com/products/pdf/XLampXP-G.pdf

Most of this data is @ 25 Celsius.

But it probably depends on the individual LED, since on the other forum a guru measured 3.26V @ 1000mA.