Fenix P3D - flickers strongly near end of battery?

Sorry about the newby question here, but can you tell me if this is working right or not? My new P3D worked fine for over an hour on high turbo mode, and then it began flickering very fast, almost like a strobe on steroids. Is this just letting me know the batteries are dying? I'm using panasonic CR123A's.

Thanks!

Dean

ps It also flickers on the next lowest settings too now, as I type this.

That's your change the battery warning, it's supposed to do that. You get a bit of use there to find your new battery.

Sounds a bit extreme. I'd have just let the light get dimmer. Is there a problem with the Fenix regulator circuit when the battery gets too low ?

Try a new battery and see what happens

If you read the instruction leaflet of your P3D under the heading "Usage and Maintenance" it says:

"If your light begins to flicker rapidly don't be alarmed, it'a low battery indication........"


So follow the instructions and don' be alarmed....

The issues is that it didn't seem to be all that near the end of the batteries' lifetime - it continued flickering and working for some time afterwards on next lowest power level, at least 30 minutes like that.

I have another 2 on order so I will compare them.

-Dean

Oh, they all do it. If you look at the runtime charts they're pretty funny looking. I'd rather they just let the light get dimmer for the end.

http://lights.chevrofreak.com/runtimes/Fenix P3D/Fenix P3D - max.png

NA8 said:

Oh, they all do it. If you look at the runtime charts they're pretty funny looking. I'd rather they just let the light get dimmer for the end.

http://lights.chevrofreak.com/runtimes/Fenix%20P3D/Fenix%20P3D%20-%20max.png

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Hey NA8 - looks like the recharegeables would be perfect - clearly they don't last quite so long but it would not be so frustrating without all that flickering. I quite like the idea of that kind of instant exhaustion. Thanks!

I believe they (AW 750mah RCR123) have protection circuits built in that cut them off at a certain low voltage level. Hence the abrupt drop off.

Several other lights flicker to indicate you need to change the batteries, soon.... Really wish Surefire would incorporate that feature in their lights. Especially their incas.

It's not a "Feature", it's the dynamic response pattern that occurs when the circuit drops out of regulation. The regulator board's ability to stay in regulation is a function of the battery's ability to maintain a set amount of voltage under load of current being supplied. Once the circuit drops out of regulation, the demand for said current out of the battery then drop accordingly. When that happens, the battery's voltage will then recover, and the regulator circuit will see the increased voltage as a sign that it's time to go back into regulation. The cycle then repeats with increasing frequency until it stays low.

I was afraid of that. Didn't think they'd put something like that out there though. Doesn't sound like a good place for el cheapo knock off lithium batteries.

NA8 said:

I was afraid of that. Didn't think they'd put something like that out there though. Doesn't sound like a good place for el cheapo knock off lithium batteries.

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Why are you afraid of it? Lithium primaries can be safely discharged way beyond usable light left.

My old P1 does this as well, my P1D CE not ... funny

CodeOfLight said:

Why are you afraid of it? Lithium primaries can be safely discharged way beyond usable light left.

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Doesn't it seem like a waste of the batteries to have the flashlight blinking when it falls out of regulation when you could be getting useful light out of it ? Hey, it's a "feature". You buy that ? Or maybe it's a poor decision by the Fenix management during development.

As for "el cheapo knock off lithium batteries" I wouldn't use them anywhere, let alone to see how they like being jerked around by a regulator circuit out of control.

Want it to get dimmer at the end? Why not just loosen the head and kick it down to High? The strobing stops until the cells are too low to power that mode, then just kick it down another level. It's that simple.

chevrofreak said:

Want it to get dimmer at the end? Why not just loosen the head and kick it down to High? The strobing stops until the cells are too low to power that mode, then just kick it down another level. It's that simple.

Click to expand...

+1

That just makes too much sense. Also note that over an hour (if straight through) in Turbo Mode is not reccomended or suggested by the manufacturer.

Ah.. that's VERY reasonable. I'd still like to see Fenix improve the circuit so it drops out of regulation gracefully, but I guess a last used mode memory would be at the top of my wish list at this point.