L4 going out of regulation early?

It could be that I lack a sense of time, because it is hard to measure with intermitent use, but it seems like my L4 went into intermediate mode long before an hour was up.

I put fresh batteries in and it's back to full brightness. Maybe I had a bad set of batteries [they were the original SF's that came in the light].

Has anybody else seen this?

I'm glad you brought that up, because my e1e did the same thing. I will have to run a controlled test to see if that was a fluke or if I should send it back to SF.

Chuck

I had an E2/KL1 flickering and going dim after about 1/2 hour, it wasn't the switch or any electrical contacts. It had 2 Surefire 123's in it from the factory, and 1 of them died prematurely.
Rob

I think with the intermittent use, even lithiums have a tendency to self-discharge a bit, so that might be it.

I had a pair of fresh lithiums in my direct drive SNII and I used it for around 15-20 minutes and was still superbright when I was done. It then sat on my shelf for a few weeks. Turn it on one night and even my KL1 was brighter...
Normally, the SNII can get 40 minutes.

Put 3 new SF123's in and we were back in business.

-Jason

Same thing happened to me the other night with no more than 10 minutes continuous use of me L4. Might be unfresh batts.

I bought a digtal multimeter from Radio Shack. It shows a voltage of 3.2 on a "New" Duracell 123.

Both of the "old" SF 123's that went into intermediate regulation on my L4 are showing a voltage of 2.85 volts.

For someone who took one electronics class 30+ years ago, can someone tell me if that adds up? Is the L4 suppose to drop into it's second stage of regulation at about 5.7 volts?

No - supposed to work down to 3-ish it seems - might be your cells do break down in vltage under load - we had reports of failing SF 123´s lately so this migth be that problem too ?

Klaus

Thanx for the quick response Klaus,

Remember one class 30+ years ago [read idiot] ... what is the easiest way to check voltage under a load? I don't have any resistors or other electronic parts laying around?

Edit: My multimeter has battery test settings, but not for 123's, just C + D cells. Can I use that?

To check voltage under load you need to access both the anode and cathode of the assembly - quite difficult to do inside the body. Why not just swap 1 cell at a time and see with which cell removed it will start working again ? The removed cell then is subject to having caused the problem - you might even decide to call SF or ship it in as SF seemed to be interested in getting such failing cells to look into the issue which had been surfacing here a while ago.

It well **might** be that the unit will work in both cases (whichever cell swapped out) - then the harder way will be to do some free-air testing with maybe both cell together connected to the head and a wire used to connect the back end to the outer ring of the head contacts - then you need a DMM to check the voltage under load of each cell - but this might be too much to check and I fear you don´t have the equipment.

Klaus

Well Klaus,

I really had my doubts. Since the light just barely fell out of high regulation this morning I assumed the boost of a "new" battery would bring it back into regulation on either of the "old" batteries.

I was wrong, wrong, Wrong. One of the "old" batteries coupled with a "new" battery works OK, the other "old" battery stays in moon mode [or whatever they call it] even with the assist of a "new" battery.

I hope this is telling me that my flashlight is OK, I just happened to get a hold of a defective battery.

You think I should return the battery to Surefire?

Edit: And a big Thanks for your help.

When the L4 goes out of regulation, is it an abrupt change like my Arc ls, or a gradual dimming like my Badboy 400? I'm still on the original batteries that are still going after a week of constant use so I haven't found out yet.

I don't think it technically goes out of regulation, it just jumps down to the next lower level of regulation.

It is quite sudden, no warning at all.

I'd call it a "flip of the switch" rather than a "dimmer" type of downgrade in describing the change in output when the circuit decides to lower its regulation point...

[ QUOTE ]
kz1000s1 said:
I'm still on the original batteries that are still going after a week of constant use so I haven't found out yet.

[/ QUOTE ]

Wow - what flashlight/cell magic did you perform to get a week of constant use out of one set of cells - this is fantastic and almost too good to be true /ubbthreads/images/graemlins/grin.gif


@flashlightOCD - you are very wellcome - I wasn´t shure about it too but the more I´m glad it worked for you - and yes I think Surefire will be happy to get such a failing cell into their hands to troubleshoot the problem - if you are looking into such a sporadic issue first thing you need are some failing parts to be able to trace the issue to the link causing the problem - they might even send you a replacement cell - just write a short note to them explaining what happened and what you did to isolate the bad one. And I´m shure your flashlight is doing just fine.

Recently we had posts from a new user named SF_Batteries on the forum who indentified himself as Eric Kreis, SureFire Battery Marketing - you might want to address him directly.

Klaus

Klaus, the next time I used my L4 after I read your last post it dropped out of regulation. A very abrupt drop from full bright to Arc AAA level. I was hoping the next level down would be brighter than this, at least for a short time.

The batteries measured 2.65V at this point. Date code 03-2013. I definitely got my full run time out of them.

Re: SF 123 duds?

I just had a very similar issue with an E2e except it went completely dead.

I posted a detailed description in the battery forum, but want to ask if anybody else has noticed problems with SF 123 batteries going bad prematurely [one bad cell]?

Edit: I'm not alone.

http://www.candlepowerforums.com/ubbthreads/showflat.php?Cat=&Board=UBB6&Number=265266&page=6&view=collapsed&sb=5&o=&fpart=1&vc=1