Regulation w Lithium Batt-is it that important?

Here has been my experience with Direct Drive lights:

With Alkline Batteries, you get max power/light for the first 10-30% of the battery life, then the batteries slowly drain, giving gradually less and less light. There have been many times that I changed out a set of "perfectly good " Alkline batteries, becuause I knew that a fresh set would give me a little more brightness, and that is what we flashoholics go crazy over.

However, I have noticed that with my DD 5 watt LS lights, that all take 123a Lithium batteries, my flashlights stay pretty close to max brightness until the batteries are almost depleted. Then it is a VERY fast downhill ride, unike alkalines, that have that long, slow, gradual decline.

It seems to me that from the time that I notice that my light is growing dimmer, to the time that it is just about dead is a very short time compared to an Alkaline battery.

So my question to yall is, do you think that regulation is really necessary in a Lithium operated light?

I know there is a "trade off" in efficiency when using circuitry to regulate a light, in that some power is lost to the run the circuitry.

I guess I am not asking for an answer to this question, but your thoughts.

i don't have any direct-driven led lights, but with direct-driven incandescent lights i do notice the brightness dropping off with use, and consequently the tint changing drastically as well. whilst the discharge curve for lithiums are supposedly flatter than alkalines, there still is a curve, so to speak. some of the runtime graphs i've seen of direct-driven incandescents support my observation.

so in my opinion, i think regulation is something i'd always look for in a light. i don't mind sacrificing some runtime, knowing that the light will always be putting out the same amount of light as when the batteries are fresh. it might even result in more real runtime, since i wouldn't be compelled to swap out the batteries as soon as a notice a small drop in brightness /ubbthreads/images/graemlins/smile.gif

I go against the grain of most here. I don't want a regulated light to go into "moon" mode (whatever) or just quit at an inopportune time. This is, to me, about the same as an incandescent bulb blowing (a no no to us all).

Most of us know it's hard to tell a 30% or so difference, even between two lights, so I am happy to just use the light until I want to replace to batteries.

If I CAN'T, then I have a long time to be able to use the light to get myself through whatever I needed the blasted thing for in the first place. This goes double for LEDs, they won't change color, and remain useful far a long time.

Re: Regulation w Lithium Batt-is it that importan

regulation with some kind of battery indicator would be the top.
I am starting to dislike unregulated lights as me too, I want the same brightness every time I switch my babies on ...
bernhard

Re: Regulation w Lithium Batt-is it that importan

I wonder if Mr Bulk has any comments on this.

I own one of his Space Needle II's [driven by 3x123] and my experience so far has been fairly constant strong output with a very steep decline just before the batteries die. It almost acts like it is a regulated light [IMO].

Re: Regulation w Lithium Batt-is it that importan

chamenos and John K,

You emphasise my points with your posts.

Incandecents and Alklines and Direct Drive start degrading from minute one (well not exactly, I get 2-3 good hours from my P/T Surge before it starts to dim)

AND, Lithiums, even in direct drive, go into "DIM" mode pretty quickly, almost as if there WAS regulation.

Re: Regulation w Lithium Batt-is it that importan

i agree the lithium powered lights tend to seem regulated, but in my surefire c2, i definitely notice the light output dropping off, even if only by a bit. i suppose a non-regulated light might be a wiser choice if one were to use it as an emergency or shtf light since a regulated light might quit unexpectedly. other than that for most everyday utility uses, i think i'd like to have regulation /ubbthreads/images/graemlins/smile.gif

btw, white leds do change in tint as the batteries die...they tend to get more yellow or green as they dim. i suspect this might have to do with a the light output of the phospher coating being non-linear, hence not always putting out the colour spectrums its supposed to at the same level than the blue led is emitting light. this is just a theory on my part though; does anyone know for sure?