how many batteries needed to bug out?

How many CR123A batteries will be needed if one holds out in houston for 12days using 2 battery LED flashligh such as gladius or PM6 3watt ?

PM6 3watt has 4hrs runtime.
I am curious if anyone has experience with this scenario.

Need to know the runtime of the lights and how much you intend to use them!

Hello Picard,

On a recent 8 day camping trip I took an L4 (with a Pila), a HyperLuxV, an ARC LSH-P, and an eternaLight. I brought 4 extra CR123 cells, but never needed to change batteries.

Tom

picard said:

How many CR123A batteries will be needed if one holds out in houston for 12days using 2 battery LED flashligh such as gladius or PM6 3watt ? I am curious if anyone has experience with this scenario.

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I don't have experience with precisely that, but I can tell you what I would do.

I would want the minimum capability to have light for 50% of all dark hours, with say 25% of flashlight use being on a bright setting.

Let's say the light is my SureFire L2: 1 hour runtime on bright and 12 hrs on low. I am not familiar with the others' runtimes.

The total time when the light will be on (50% of all dark hours) would be half of 12 days at 12 hours per night. That's 6 hrs per night for 12 nights -- 72 hours total. 25% of that is bright -- 18 hrs high beam. 75% is dim -- 54 hrs low beam.

In order to do the 18 hours of bright, you need 18 complete changes of batteries -- at two batts each that's 36 batts for bright use.

For the dim use you will need 4.5 changes (54 hours divided by 12 hrs per change equals 4.5 changes. So that's another 9 batteries. Make it 10 because they have to be used in multiples of 2.

So there you go. Your nearly 2 weeks of no power requires 46 lithium primary cells. You would buy 4 boxes of 12 from SureFire for $15 ea. for a total of $60 for 48 batteries before shipping.

If you used only the low beam of the L2 you would get 12 hrs per change for the whole 72 hrs of light time, then you need 6 changes or 12 batts -- only one box.

I think if you were a rescuer or law enforcement officer, you'd use a whole lot more than that (mostly because you need a lot of bright time for that work). Probably the average homeowner would use less. Figure half a box for the homeowner and 6-10 boxes for the rescuer/LEO.

Scott

You want light 50% of all the dark hours for TWELVE DAYS? Are you never going to sleep?

Hello Bezaur,

I have to agree with Paul, you are not leaving much time for sleeping.

The camp out I was on was with a bunch of Boy Scouts and I liberally passed my lights around for everyone to try out. My plan was to run the first set of batteries down, then ration the use of the lights.

With 8 people trying out my lights each night, I was surprised that I did not have to change batteries.

I should also mention that our use was around camp and we had no search and rescue exercises. I also made sure that the lights were turned off after use. It seems we spent most of our dark hours sleeping.

Tom

I want light for 12 hours all twelve days. It doesn't need to be much though.

For that purpose I have a 4-AA touchlight with a dorcy solid state single LED bulb in it and it will run about a week or two of nights on one set of rechargables. I also have some of the one "D" cell energizer lanterns that will go as long. Add a couple MJLEDs in minimags and a PR based MJLED in a 4-D lantern resistered down as a two stage 2mA low 75mA high and 3-4 folding energizer lanterns (LED) and my long term low level lighting is taken care of.

I could get buy with NO replacement batteries but would be happy with 4-8 "D" cells and a 24 pack of "AA".

Now for bright I have two 2-D mags running a 3-watt clone at a little over one watt. The one I tested ran for 30-40 hours so one set of 4 replacement batteries might be nice but not needed.

I also have a few 123 based 1 and 3 watt LEDs and incandascents. I would be happy with 12 replacements.

SO not countuing my gas and propain lanterns and assuming I can't recharge my rechargable AA's, to go 12 days with all the light I need or want I would need a total (Including the ones in the lights) of 20 "D" cells 30 AA cells and 20-24 123's.

With this set up and actuall use I would probably actually be good for 2-3 MONTHS.

wwglen

When I go on a trip, I usually plan on it lasting longer than expected, so some buffer qty is good.

Under those kinds of conditions, your "work day" can be pretty long, and the lack of conventional lighting makes you very dependent on your lights at night and even many indoor situations.

If there are kids around under those kinds of stresses, a low level candle sort of light can be a great relief, and can end up running virtually constantly.

paulr said:

You want light 50% of all the dark hours for TWELVE DAYS? Are you never going to sleep?

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Only *between* watches.....

Doug Owen