This is pretty typical for 4AA lights, esp. incandescents. The AA lithium cells have a slightly higher initial voltage and when you multiply it x4, can often be enough to blow bulbs.

-john

I don't have any, but it sounds like they work fine. You can convert your existing lights by dropping in a SF P60L lamp assembly or one of the after market versions.

My take on it is that at least some of the after market versions are better for brightness, efficiency and cost, but I'd probably stick with the SF lamp assembly if being used as a tactical light in conjunction with a firearm.

-john

Yes, never buy 123A cells from a brick and mortar unless you are totally desperate. It is MUCH cheaper to buy on-line.

Personally, my preference in terms of performance and reliability is something like:

- Streamlight
- Surefire
- Eveready
- Duracell
- Sanyo

-john

The Zebralight H30-Q5 and H60 are pretty sweet headlamps. I'm totally addicted to my H30. The only real downside I see is that the button can get activated accidentally when in your bag.

-john


OK, someone keep me away from the "post" button!

Big +1 on buying online AND on your choice of brands, with the exception of Eveready with which I have no firsthand experience. I have a reasonably priced local source for Surefire batteries but I usually purchase Duracell Ultra 123As online and in bulk.

I particularly favor the Ultras for multiple battery applications.

From what I've heard, the SF and Duracells are basically the same battery, with SF making some tweaks in the fusing due to some of their high drain applications.

Performance in the SF and Streamlight are about the same also, but at the time I was deciding what to use, SF was having some problems slip past QC, so the Streamlight was a bit more reliable.

-john

From what I'm reading, when using lithium batteries (CR123's) in pairs or triplets - regardless of brand - its recommended that you get a good meter, and before use, test each cell to make sure they have full (equal) charges. I guess it is dangerous to put a full battery with a nearly spent one - that can result in dangerous conditions (exploding).

A commonly recommended meter:
http://www.ztsinc.com/minimbt.html

I got one of these a while back and it is nice.

A Good old fasioned multi testor works for measuring batteries and for a number of other tasks as well.

Yes, my understanding is that the problem is when one cell reaches empty and an other cell still has power, it will reverse charge the empty cell and possibly cause the dangerous condition.

I'm not sure I've heard that battery companies suggest you measure the cells before using, and for most users, simply making sure all the cells are fresh and of the same make and model is probably sufficient.

That said, your procedure certainly wouldn't hurt, especially with rechargables where you are more likely to accidentally use a discharged cell.

People should keep in mind that the rechargable 123A cells output higher voltage than the primary 123A cells, and there are VERY FEW applications that allow for more than one 123A rechargable cell.

Basically, you can't just drop 2x rechargable 123A cells in your average SF light.

That said, the 18650 lithium ion cell is almost the same dimensions as 2x123A cells, and with certain lights that employ power regulation, it can be used (note the voltage with 1x18650 will be lower than 2x123A, so a regulated light is a must).

Example lights where this can be done- the HDS EDC lights, the Surefire U2, Fenix TK11.

As always, research the specifics before you do something and treat it with respect.

That said, I'm not trying to scare people off of lithium batteries, either primary or rechargable. I pretty much exclusively use these two technologies. It is excellent technology.

Just be informed and treat it with respect like you would the use of gasoline, a firearm, a knife, automobile a boat or mother nature.

-john

Thanks for the tip on the zebralight, the H30 seems like my ideal headlamp for backpacking. I've been looking to replace my Princeton Tec quad, which eats batteries, and turns on easily in my pack. This addresses those issues and uses the same batteries as my Fenix.

On a side note, for those looking for a cheaper AA flashlight, I can't praise the Streamlight Propolymer Luxeon highly enough. The batteries last a long time, fully regulated, and the optics are the best I've ever seen. The focus makes it seem far brighter than it technically is, and it compares surprisingly well with my Fenix on hight at 215 lumens! It's waterproof and has taken quite a beating. I've used lithium cells in it with no problem. It costs about $30 at brightguy.com The LED is a couple years old, not the latest high tec Cree, but this is a fantastic, high quality light.