SF L4 falls out of regulation early

My new L4 seems to have fallen out of regulation after not more than one half hour of use (on the Surefire batteries that came with it). I have a dozen new batteries coming from Surefire on Tuesday so I cant test it with new batteries until then.
I know the light was not left on inadvertantly. Were the batteries that came with it just bad or is it possible something else is going on?
The light was bought new from OpticsHQ after a backorder of about three weeks while they were waiting for a new shipment of L4's from Surefire. I believe this light was from that new shipment so I dont see how the batteries could have been bad. What do ya think?

How did you use the light? Were you holding it the whole 30 minutes?

Bill

Sometimes Surefire batteries are defective and fail early. I've started buying other brands, but I haven't used them enough yet to know if they have any premature failures, too.

Before you worry too much about your new light, assume that this was a battery issue. More likely than an electronic problem although that is possible. A regulator circuit failure will usually not be that subtle.

Can you measure the V of the cells you used? You might find one or both of them well below 3V.

The usage on this light was intermittant not continuious.
Also, the light did not fall out of regulation before my eyes. The second to last time I used it and it ran at full brightness, picked it up a day later and it was out of regulation. In between it was locked out so it could not have been on without me knowing it.
As far as testing the batteries all I have is a cheapo multi meter that has settings for 1.5 and 9 volt batteries. Can this tester be usefull in some way to test the 123's (especially the new ones)?
When the new batts come I will try to keep a close eye on runtime and hope it is closer to the 1 hour advertised. It's my first Surefire and a beautiful little light---I hope I have a good one.

I have been using Battery stations 123's, and I have had great luck with them.. You should put some serious thought into some Pilas, they are a perfect match for the L4.
Your meter doesn't sound like it will do the job your after, those batteries can be pretty delicate when it comes to voltage, I have had my light fall out of regulation with well over three volts per cell. It is a very fine line.. Bad cells from Surefire isn't a terribly uncommon occurance..
Good luck!

If it turns out not to be a battery issue, get a pair of those cheap cardboard solar eclipse gogles (if you know what I'm talking about) or welding gogles. You can then look directly into the LED to se if all 4 dies in the Lux V are lit up with equal intesity. There have been cases where a string of two dies burning out in Lux V's.

Jan

Numbers said:

The second to last time I used it and it ran at full brightness, picked it up a day later and it was out of regulation. In between it was locked out so it could not have been on without me knowing it.

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Nearly all of my early Surefire battery failures have happened in exactly the same way.

dito to Andrew ... sounds like a battery issue ... it isn't that common, but it happens.
bernie

P.S.: if you have a single-cell light test the two batteries ... you might find one dead and one still working ...

JanCPF said:

If it turns out not to be a battery issue, get a pair of those cheap cardboard solar eclipse gogles (if you know what I'm talking about) or welding gogles. You can then look directly into the LED to se if all 4 dies in the Lux V are lit up with equal intesity. There have been cases where a string of two dies burning out in Lux V's.

Jan

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...or you could just cover the bezel with a sheet of paper

Ok, New batteries installed and light is running fine --- for now. I will keep a close watch on run time and hope I achieve the advertised + - 1 hour. I did note that the new batteries received today have the same expiration date as the ones that came with the light and apparently failed early. I hope the new ones are not a part of the same production batch as the failed ones. If I cant get at least 1 hour out of a set of batteries this is going to get expensive. In fact I was sad to see on the "if you could start over" thread that several members would not have bought the L4 because of the short run time.

This comes up again and again.

A 123 lithium cell's output is INCREASED by the heat of running. If the cell is used to right-at-empty, the heat will let you get that little extra out of it.

After it cools, it's worthless. And that was what you found the next day.

Still, 1/2 hour is low. But that just sounds like a weak cell.

could be also the luxeon lottery at work, if you have a higher Vf binned LuxV your runtime combined with cold cells can create such a senerio.

Numbers said:

Ok, New batteries installed and light is running fine --- for now. I will keep a close watch on run time and hope I achieve the advertised + - 1 hour. I did note that the new batteries received today have the same expiration date as the ones that came with the light and apparently failed early. I hope the new ones are not a part of the same production batch as the failed ones. If I cant get at least 1 hour out of a set of batteries this is going to get expensive. In fact I was sad to see on the "if you could start over" thread that several members would not have bought the L4 because of the short run time.

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You do know that you can run this wonderful light on a rechargeable Li-Ion cell right? It will run in full regulation for about 40-50 minutes, and you can get the cell (17670) from our member AW right here: https://www.candlepowerforums.com/threads/97268

Jan

Yes,
I started researching rechargables last night. I have a question-- What is the difference between the AW17670 and the pila168s? Is it price only? Looks like this might be the way to go, with primaries for back-up.
I will need to do a bit more research I would like to know/confirm if the charger for this battery can be used to charge other types of batteries or other sizes of lithiums.

Numbers said:

Yes,
I started researching rechargables last night. I have a question-- What is the difference between the AW17670 and the pila168s? Is it price only? Looks like this might be the way to go, with primaries for back-up.
I will need to do a bit more research I would like to know/confirm if the charger for this battery can be used to charge other types of batteries or other sizes of lithiums.

Click to expand...

AFAIK they are the same size, only from different manufacturers. Aw's 17670 comes in protected and unprotected forms while Pila 168s, i believe are all protected.

Aw's DSD multi-bay charger can charge the common lithium ion sizes such as 16340, 17670, 18650s. For 17500s and 18500s, he can supply a copper spacer or you can roll up a piece of aluminum foil and tape the sides (although resistance higer than the copper spacer).