When does the KL1 fall out of regulation?

Owen

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I think this has been posted, but I can't find it.

Reason I ask:
Was playing around today, and took the old batteries out of my X5 (which is considerably dimmer than with fresh batteries), and checked them. They were at 2.03v apiece. With those batteries, the KL1 was still adequately bright.
About equal to the X5 with new batteries (3.28v/ea.), which I put it alongside. I was surprised-an impressed. Didn't really think batteries that were no longer giving good output in the X5 would be worth anything in the KL1. To tell the truth, I was thinking that when my E2e/KL1 batteries got low, I could use them in the X5. Guess I see what all the fuss is about regulated lights...
I'm assuming that my KL1 has already fallen out of regulation since it's dimmer than with fresh batteries, and would get continuously dimmer if I left those batteries in it(?).

Does voltage tell the whole story, or is there more to it? I know that volts x amps = watts[output], but am curious about how regulated lights work. Do they step up the voltage, or ?
 
I too, would like to know at what voltage the KL1 drops out of regulation. Is the 2.03V an unloaded V measurement? The KL1 on an E1 gives about one hour of regulated light - and that of course STARTS at just over 3V. But then a KL1 at 3V is not as bright as a KL1 on 6V... and you're showing 4V.

The more I write, the more I realize I should let somebody who actually knows some EE respond.
smile.gif
 
It's an unloaded measurement. I don't know how to get a loaded measurement on this light, having no equipment except a digital multimeter.
I put those old batteries back in the KL1, and am running it now, to see how much longer it will run at "fresh" X5 brightness. Nothing scientific, just satisfying my curiousity.

edit: that didn't take long. 5 minutes, and the output is about 1/4 what it was at the start, and the batteries are down to 1.2v/ea. Doesn't really mean much to me, since the measurements came at the tail end of battery life. When your batteries get low on the KL1, you'll definitely know, though!
I'm going to keep running it, to see how long this "moon" mode will last.
 
Actually the KL1 on one 123 starts falling out of regulation after approx. 1 hour in the tests I have done, after an hour it very-slowly drops into moon mode. This is slow process, unlike the new Arc LS that quickly drops into a very low light "moon mode" condition. The KL1 I have is at 70% brightness even after 2 hours. So I would say that it tries to regulate whatever power it can muster from the batteries instead of having a set cut-off point. For this reason, the KL1 works very well with the rechargeable 1/5A batteries I have, running as bright as possible without over draining the batteries.

Well, that's what I think anyway.
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Originally posted by Sean:
Actually the KL1 on one 123 starts falling out of regulation after approx. 1 hour in the tests I have done, after an hour it very-slowly drops into moon mode. This is slow process, unlike the new Arc LS that quickly drops into a very low light "moon mode" condition. The KL1 I have is at 70% brightness even after 2 hours.
<font size="2" face="Verdana, Arial">Glad to hear it keeps working longer after the initial brightness drops off. An additional 5 minutes, and my KL1 was down to Photon II brightness. The batteries will barely light a X5, and just went in the trash. Guess my little "test" was pretty meaningless, since it's obvious the batteries were on their last leg. The SF123s in it are still reading over 3v, and have been used with a MN03 part of the time, so I have no basis for an opinion on the KL1 vs batteries yet. The old ones had been in the X5 since May-actually were a split Duracell 223, and it was used almost daily.
Still surprised that the KL1 was so much brighter with the same old batteries. I didn't realize the LS (I know ~zero about these things) was so efficient.
 
FYI.
Here is a runtime plot I did last week on a E1/KL-1. The plot is of the current generated in a photocell over time.

kl1-1.jpg

ADDED: This is a single cell plot!
 
Mine started to tumble a couple of minutes after four hours on fresh SF 123's.

Brightnorm
 
Originally posted by Owen:
... Guess my little "test" was pretty meaningless, since it's obvious the batteries were on their last leg...
<font size="2" face="Verdana, Arial">On the contrary, Owen. You seem to have shown that the KL-1 maintains a more "usable" level of light out of a pair of batteries than an X5-T before quickly (abruptly?) dropping off to "braille-by-stubbed-toe". I was glad to hear it, as I'd put off the purchase of an X5-T to see how the KL-series lights would perform. I have an order in for a KL-1 and KL-3 based on experiences such as yours and others'.
 
*** Warning ***

I see that some folks are talking about 2-cell regulation and 1-cell regulation. The KL1 on an E1 will NOT give you four hours of regulation. But it will on an E2. If you want efficiency out of your KL1, use it with 6V!
 
Darell, good point! I hope I didn't muddy the water by presenting my plot here. A two cell (6v) plot is planned in the near future.
 

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