Please don't flame me, but I think if there is a true emergency for anything over 3-5 days those flashlights would eventually become unusable. AAA, AA, C or D size batteries are so much more prevalent. Also LED flashlights run just fine off of them.
Somebody explain to me why those Lithium battery powered flashlights are so hot? <img src="/images/graemlins/confused.gif" alt="" />

There are some advantages. They have a great shelf life (so there is no reason to have no supply at hand). And they function also better by low temperatures.

most lithium powerd lights are usually used in the high performance kind. For most situation that performance is overkill, but people just like things that can do much more than they actually need it to do. It's just like people driving SUV's in the city.

I'm trying to convert all my equipment to AA batteries, due to there avaibility and reasonable capacity. I only have problems finding a good headlight that i like and runs on AA's... I hate battery packs on the back of my head.

The lithium chemistry has longer shelf-life, higher power density, and better performance in the cold. And they are lighter (which matters for EDC, in headlamps, in torches which float etc).

You can get lithium batteries in an AA form-factor, so I'm guessing you are bothered about CR123s. Whether they will be easily available in shops during a disaster depends partly on where you are. Around here my local supermarket stocks them as camera batteries. My understanding is that then there's a crisis, all the AAs etc are in high demand by everyone, and get sold out quickly, but people are less bothered about cameras and so 123s remain available.

One of the benefits of the long shelf-life is that it's more practical to stock-pile them at home. Then you are not so dependant on shops. If you have a dimmable LED torch, eg an SF L1, and you buy batteries off the internet, $22 will buy you about 20 batteries which should last about 800 hours of continuous on. That's a lot more than 3-5 days.

If you want longer than that, then I have to wonder what kind of disaster you are talking about - maybe this should be in the "long-term survival" section. I would be looking at rechargable batteries and a solar panel or petrol-powered generator or something. And then the chemistry would be Lithium-Ion.

I'm not telling you to use lithium, I'm just saying it's a defensible choice depending on the situation.

Why?
Power density - a CR123 based light will either give you a lot MORE light for the same size, or be smaller.

That said, I think the best light for disaster use are "dual battery" - My old ARC LS came with both a CR123 tailpack, and a 2xAA tailpack - I understand that the EDC ultimate now has a AA tailpack, but as funds are REAL tight right now, I have not looked into this

I know I can get a LOT of hours on my CR123 based ultimate - simply by NOT using the highest setting. I think I've changed the batteries 2x in the year I've had it

The issue is more one of punch v duration. You can have one but not the other (yet). I have been into this in more detail elsewhere. Try doing a search. <img src="/images/graemlins/smile.gif" alt="" />

As others have said, for me it's the long shelf life and a lot more power in a smaller package. Someone else mentioned better performance in the cold, but I seem to notice they hold their power better in the hot car during the summer too.

My complaint used to be their cost. A pair of CR123's will still cost $9 in your local store and that's outrageous. A box of 12 Surefire lithiums is around $20 over the internet, but even better is the prices Battery Station has:
www.batterystation.com

Battery station has discounts if you are a member of some other forums that will get the price down to $1 per CR123. In runtime tests their batteries are the equal of Duracell, Energizer, and Surefire batteries. I've been using them for a while and have no complaints. Also, Battery Station now ZTS tests every lithium battery before they are shipped. (Battery Station also still has a few of the HDS Basic 42XR's on sale. It's a super deal on a great flashlight. Any buyers remorse will disappear the first time you use it. Equal in durability and warranty with Surefire.)

All of these factors add up to be a no brainer with my EDC light, and a couple of others in my regular use.

candlepowerforums will answer all your questions and more.. As people mentioned already, the benefits I see in Lithium is:

Shelf Life
Weight
Longevity
Cold weather

Exactly in that order.. You can get Lithium Batteries in AA and AAA(energizer, not cheap).. Have them and use them in my EDC, BOB, and stocked at home and car. The Used by date? 2020

I actually use 2 AAA Lithiums in my EDC LED flashlight. Please note that the initial output of Lithiums tend to be higher than 1.5v. Double check with your electronic manufacturer to see if they accept Lithiums.. Another way is just to run the batteries in a high drain device temporarily, and then transfer the batteries over.. (me, I just put them in) <img src="/images/graemlins/smile.gif" alt="" />

In regards to weight, I just weighed them on a kitchen scale.. An Energizer AAA Lithium weights in at 7 grams whereas a Duracell Ultra (Alkaline) AAA weighs in at 11 grams. So 3 Lithiums will weigh less that 2 Alkalines..

I was going to respond with a comment about energy density and how I have over 1000 hours of very useful light in a drawer in my kitchen in the form of 100 CR123As.

Instead, I'm going to ask about the "coincidence" of having a known hot topic posted by a guy offering a special deal to ETS members. Wouldn't be an attempt to get eyes on product, would it?

Well, believe it or not, it is a coincidence.
I see where you are coming from, and appolgize if this was interpreted the wrong way.
The truth is, some of my relatives were buggin me with this question all last week and I couldn't find any satisfactory answer on the net, so naturally I posted it here. <img src="/images/graemlins/laugh.gif" alt="" />

Thanks for all the responses.
I suppose there are instances when coin cell batteries are superior to AAAs etc, for example in such flashlights as Photon, and Inova, but I am still not converted as far as the bigger lights go.
One argument I agree with is that of Brangton. He mentioned that during an emergency there will be a run on the stores to get all the AAAs etc people could find, but 123 may remain untouched. And of course that of specialized applications, when density is more important then the duration.
I realized now that I should have posted this in the long term prep forum. Sorry. <img src="/images/graemlins/blush.gif" alt="" />