L4 users - when do the batteries start to die?

[kinzli]

Hi everyone, I'm sorry if this has been asked before, I searched and didn't find anything specifically about this, hopefully I'm barking up the right tree /ubbthreads/images/graemlins/smile.gif

I just got an L4 not too long ago and am on my first set of batteries. I haven't used it that much besides shining it in my eyes a few times, and turning it on briefly numerous times a day.

I'm wondering how I'll know when the batteries are getting ready to be replaced.

Does it become very obvious that the light is no longer within regulation, i.e. the beam is much less bright? I *think* it's getting dimmer, but I'm not sure if that's just me or if it's really happening...

Is there a rule of thumb for figuring out when cells need replacing?

Thanks...

 

[this_is_nascar]

You'll know. Once out of regulation, brightness drops rather quickly.

 

[Kiessling]

it will stay in regulation (=same brightness) for about 65 minutes and will dimm drastically after that time, you'll notice, trust me!
one "early" sign a few moments before falling out of regulation can be a slight flickering of the light.
bernhard

 

[RevDavid]

They will drop out of regulation after about an hour of runtime... then will continue to work at lower output for some time... but I replace mine when they fall out of regulation. There's nothing wrong with the lower output, but I already have the TW4 for that, and it is smaller. Since I EDC the TW4, I am guessing my L4 will go for months before I need to replace the batteries.

David <><

 

[jtice]

How much dimmer is the L4 after it drops out of regulation?
60% 50% 30% ?

 

[FlashlightOCD]

It will be dim enough that you will know for sure it is out of regulation, I don't know the percentage but it will be obvious and it will be without warning ... no gradual dimming.

If I was to make a WAG I'd say it drops by roughly 83.23%.

 

[Roy]

Someone loan me a L4 and I'll do runtime plot on it. Might even send it back! /ubbthreads/images/graemlins/grinser2.gif /ubbthreads/images/graemlins/thumbsup.gif

 

[Kiessling]

the "moon mode" of the L4 is not that bright ... you're left in the almost-dark in less than a few hours ...
bernhard

 

[sakane]

Although I've only had my L4 a few days, I did put in some pre-used-up batteries. You'll know when your L4 needs new batteries. When I turned the L4 on, it lite up brightly, then abrubtly went into low-moon-light mode.

 

[6pOriginal]

One way I found out when it's not in regulation anymore is that the bezel is not as hot as before /ubbthreads/images/graemlins/tongue.gif In moon mode, it seems to last forever, and it's pretty useful for me since I don't have any other lower output LED lights. I actually use "dead" batteries from other incandescent lights pretty often on the L4.

 

[IlluminatingBikr]

There seems to be some variation in moon mode for the L4. On one set of batteries, moon mode was a flicker or two then the light wouldn't even light up! Second set of batteries, and moon mode was brighter than a photon for quite a while. /ubbthreads/images/graemlins/icon3.gif

 

[6pOriginal]

[ QUOTE ]
IlluminatingBikr said:
There seems to be some variation in moon mode for the L4. On one set of batteries, moon mode was a flicker or two then the light wouldn't even light up! Second set of batteries, and moon mode was brighter than a photon for quite a while. /ubbthreads/images/graemlins/icon3.gif

[/ QUOTE ]

That's interesting...so far I only ran about 3 sets of batteries thru the L4 and they seem to be about as bright or even little bit bighter than my Arc AA pretty much till the batteries die for real /ubbthreads/images/graemlins/thinking.gif

 

[LEDagent]

Here's my answer: The batteries start to die as soon as you push that button.

Here is a more educated answer from data taken straight from Brock's review page and put into graph form:

His data can be found here: Brock's Runtime plots

It looks like it stays fairly constant after 5 minutes and before 75 minutes or so. After 75 minutes it looks like it falls out of regulation and decreases in brightness rapidly. I think after some time the the brightness will level off to something more constant, but it will be dim. The last time my L4 went out of regulation it was about half as bright as the Arc LSH-P.

 

[kinzli]

Thanks everyone for the replies!