AA Alkalines and Lithiums Interchangeable?

[JerryM]

I am wondering if one can interchange the two types. I am wondering if I can use lithiums in my Dorcy 2AA 4LED light.

In some lights the lithiums make the light brighter, such as the CMG Reactor, and in some they do not make much if any difference, such as the Ultra.

Is there danger of blowing the bulbs or LEDs with the slightly greater voltage from lithiums?

Thanks,
Jerry

 

[Steelwolf]

The increase in voltage is very slight, about 0.2V. This should only be a concern when running more than a few cells in series as the slight increase will soon add up to the equivalent of an extra cell (like when you're running 8 in series).

With your Dorcy, there should be no noticeable difference in brightness. There may also be no noticeable increase in runtime as the current drain of 4 LEDs is not great and the low internal resistance of lithiums would not play a great role. The only things you might benefit from are the flat discharge resulting in a more constant level of light (only if the Dorcy is a dumb boost, ie non-regulated), good cold weather performance, good heat tolerance and very good leak resistance.

Hope that helps.

 

[PhotonBoy]

The Dorcy has a booster circuit in it, so the .2 V difference would be boosted also. It might increase to about .33 V; I don't have that type of light, so it would need to be measured to find the actual difference. I think there would be a slight increase in brightness.

 

[JerryM]

Thanks to both of you. I was not going to try it until I had some advice as to the danger of blowing the LEDs. I figured that it would be OK, but appreciate the advice I get here.

Well, I guess that I will just have to put up with withdrawal pains until Monday when CPF gets back on line.

As a sidelight, I compared the 2AA 4LED Dorcy with the CMG Reactor. The CMG with lithiums was a little brighter, but not a great deal, and considering the difference in size I would rather carry the Dorcy. I was expecting the Reactor to be significantly brighter.
The CMG has a large head, and is more difficult to holster.

Have a good weekend, and thanks again, gentlemen.

Jerry