Possible for aa batteries to hit 3k lumens? Just wondering….
No without having a stupidly large number of them. And even then the battery life would be rather short comparatively.
No.
For 3000 lumen you need about 25 watt.
At 1.2 volt that is 21 ampere, in my test NiMH had trouble at 10A. And it is even worse, the NiMH is below 1.2 volt at high current, i.e. more current needed and the efficiency of the boost converter will be low, i.e. even more current needed.
Using 3 NiMH in series will give 3.6 volt, that means about 7A (Witch will reduce the voltage to 3 volt and 8A), and is much closer to possible, but check the runtime at 8A (About 12 minutes): http://lygte-info.dk/review/batteries2012/Eneloop%20AA%20HR-3UTGB%201900mAh%20%28White%29%20UK.html
Using a single high current 18650 is a much better idea, but runtime will be about the same.
Time is also unspecified. OP didn’t mention currently or The Future…
Yes, illumination time for example.
No problem to charge a cap from a single AA and dump it into an LED to get 3klm for a short time.
If one really wanted to, I guess he could use 3 or 4 of those D-cell sized 4AA Adapters and even get a usable format. (Just like in the old times. ;-))
How about putting, says 25 AA alkalines in series? Theoretically does that work?
I regularly get thousands of lumen’s from four AAs.
Using my camera flash. 8)
Guess you could tape ten 300lm AA lights together and turn them all on.
That means about 1 watt from a alkaline AA, that is possible.
For 1/1000 of a second every 10 seconds, the average is a bit low
Some high discharge NiMH batteries I know of.
http://www.cheapbatterypacks.com/product/122/Elite-2000-AA.aspx
More like 40 watts once you factor in the optics and driver…
What does a XML2 do? Minimum 400lumens at 1a and ~2.9v?
10 x XML2s can do over 4000lumens at sub 30w
Tho a 10xXML multi AA powered light is a bit of a stretch
The OP never mentioned which LED or if more then one is allowed
Exactly, use the most effecient emitter at its most effecient drive level, then just use as many as you need to obtain the required output. My example was just an easy calculation, I’m sure better can be achieved.
Yeah, but let’s just assume highly efficient LEDs are used (i.e. XM-L2, MT-G2?) in this case, because LEDs with lower efficiency would require more input wattage in order to hit 3k lumens, which is more difficult for AA.
What optical efficiency could one expect with a ‘typical’ reflector arrangement?
Is something like 0.8 to optimistic?
9 Eneloops + 6 XM-L2s on copper should have no issues hitting 3000++ emitter lumens.
You could do with less emitters too, but in order to reach 3000 lumens I would say you should be looking at 9 batteries as a minimum, coupled with a minimum of 3 high output XM-Ls.
something like 4 x mt-g2 would be very excellent efficiency but with high cost, one can calculate the cost of the LEDs, a driver, assume 85% efficiency, and assume NiMH batteries for their better characteristics, and a reflector if its a flashlight, and body and switch
i’m a bit busy so i can’t do the math now, but it will be well over $100, probably a bit over $200, and battery life would be probably under 1/2 hr
like they say in the auto modding world, anything is possible if you have enough money
Is something like 0.8 to optimistic?
Yes, 70% is more likely… particularly with small reflectors, uncoated lenses, typical bezels. Very few lights can beat 75% (I don’t think I have ever seen one)
And assume 85% for driver efficiency (very optimistic for boost drivers, many are around 50% efficient).
Thank you!
I have some experience with most not-to-exotic smps topologies, but I have no clue about optics.
Need to read a little into that if I find decent literature.