Problem with New Fenix L2D-CE and a quick run time estimate

I received my Fenix L2D-CE yesterday, popped a couple of Targus 2500 mah NiMH batteries in and tested it in various places last night with excellent results. I really liked this flashlight. Today I decided to do some run tests on various settings, so I put two full batteries in this morning and turned it on the medium setting with a spec run time of 10.5 hrs. The light was functioning just fine for the first few hours. I happened to check it about 4 1/2 hours into the test, although the light on the wall looked fine. I was a bit shocked to find that the rubber portion of the clicky on the tail had blown up like a balloon to about a half inch radius, indicating that some gas, perhaps warm air had gotten into the space under the rubber part of the clickie.

I pushed in and the gas or air poofed out leaving the rubber portion partly pushed out of the rest of the clickie. I pushed the rubber back in with a small screwdriver and then turned the light back on to test it. I'm wondering if anyone else with the Fenix l2d-ce has encountered this issue and what it means?

Also, I turned the light back on after a short break and only got another half hour of decent light. That, of course, is an eyeball estimate. That would mean that the effective run time to less than half the light output would be slightly over 5 hours rather than the 10 1/2 hrs states in the specs. I'll try this again soon. Admittedly this is a very preliminary look, but I haven't seen anyone else report yet; very cruiously waiting for Chevrofreak's accurate technical runs.

When NiMH gets hot it can sometime discharge gas. Since the flashlight is water proof, the tailcap blows up.

Have you verified your nimh is indeed 2500mah actual capacity?

I noticed a slightly ballooning (just enough to make tail stand wobbly when using a brand new single eneloop. None of my older NiMH does this, so perhaps its just with new cells. I might put them in the charger and discharge/charge cycle them once or twice to break them in.

I think I remember this happening with someones L2P when they were using primary Lithiums?

*shrugs*

Definitely remember hearing of the ballooning button effect... I think that's probably why Fenix give you a replacement button - if your batteries vent (hopefully without flame!), then the button will be sacrificed rather than build up dangerous amounts of pressure?

That makes sense to me

That explanation makes sense to me. That's probably why Fenix includes an extra rubber button with this flashlight. I tried another runtime test on medium with what I thought were fully charged 2500 mah batteries, not tested for capacity, though. This time the L2D-CE went 5 1/2 to 6 hours without a problem. However, at about 6 hours the flashlight became somewhat erratic, especially as I picked it up and moved it about. Sometimes it went into SOS mode and sometimes it clicked off. I'm now at 7 hours and ready for bed. The light is still working, but at substantially less than 1/2 the original light output at medium. I don't know what the Fenix specs mean when they say that you can expect 10 1/2 hours on medium, but it appears that this is extremely optimistic. I'll report back on it tomorrow after letting this run out a bit before I go to sleep.

I eagerly await sometime running a more formal run time test with light outputs on this light. Although the run time is somewhat disappointing, the light output and overall quality of the light is just great and meets my expectations.

You think that's bad my modded Mag Trilux actually blew out the rubber tail cap switch cover twice during a hike last November. Basically it built up gas from some of the eight high current discharging AA NiMH cells and f*rted. Perhaps you are using the same Energizer 2500 NiMH that I was using. If so, use another brand like Duracell and your flashlight will probably stop developing gaseous discharges.

Take a look at this graph:

http://lights.chevrofreak.com/runtimes/Fenix L2D CE/Fenix L2D CE - medium.png

chevrofreak tested the L2D-CE with 2650 mAh NiMH cells and got around 11h. Maybe your batteries are faulty or there is a problem with the light itself? You should first try to clean all the contacts and try again your runtime test.

HarveyRich said:

That explanation makes sense to me. That's probably why Fenix includes an extra rubber button with this flashlight. I tried another runtime test on medium with what I thought were fully charged 2500 mah batteries, not tested for capacity, though. This time the L2D-CE went 5 1/2 to 6 hours without a problem. However, at about 6 hours the flashlight became somewhat erratic, especially as I picked it up and moved it about. Sometimes it went into SOS mode and sometimes it clicked off. I'm now at 7 hours and ready for bed. The light is still working, but at substantially less than 1/2 the original light output at medium. I don't know what the Fenix specs mean when they say that you can expect 10 1/2 hours on medium, but it appears that this is extremely optimistic. I'll report back on it tomorrow after letting this run out a bit before I go to sleep.

I eagerly await sometime running a more formal run time test with light outputs on this light. Although the run time is somewhat disappointing, the light output and overall quality of the light is just great and meets my expectations.

Click to expand...

Could be just as simple as the air trap in the light was expanded with heat.

You got a faulty battery....The good one is charging it(gas).Try running the flashlight with just one battery to find witch one is bad.

the duracell 2650 mah lauch only 1,2 volts too ?

zerafull said:

the duracell 2650 mah lauch only 1,2 volts too ?

Click to expand...

The voltage isn't the problem. I switched to these cells and no longer had the gas buildup issue.

WildChild,

Where did you find that graph? I thought Chevro hadn't finished any of this new Fenix Cree graphs yet. Do you have anymore?

WildChild said:

Take a look at this graph:

http://lights.chevrofreak.com/runtimes/Fenix%20L2D%20CE/Fenix%20L2D%20CE%20-%20medium.png

chevrofreak tested the L2D-CE with 2650 mAh NiMH cells and got around 11h. Maybe your batteries are faulty or there is a problem with the light itself? You should first try to clean all the contacts and try again your runtime test.

Click to expand...

There

http://lights.chevrofreak.com/runtimes/Fenix L1D CE/

and there

http://lights.chevrofreak.com/runtimes/Fenix L2D CE/

Yes they are not finished but some info is already there!

adirondackdestroyer said:

WildChild,

Where did you find that graph? I thought Chevro hadn't finished any of this new Fenix Cree graphs yet. Do you have anymore?

Click to expand...

The ballooning rubber button problem is exactly the same as that happened to me in February 2006.

The thread that has the full sorry story, with many good responses (including what I believe to be the definative answer from 7 sevens:


https://www.candlepowerforums.com/threads/107585

That commonly happens with the fenix and some other lights, a small pin prick in the
rubber tail cap switch works fine

Thanks to everyone for some excellent suggestions. I did another run time test with the Targus and no gas was vented this time. I decided to take up the suggestion of popping in some Duracell 2650s and see what the times were. So, here's my data up to now. Mind, the run times are only until there's a visible drop in the light output on the wall, not official times to 50% of light output.

1. Turbo Mode: 1 hr and 50 minutes, with an additional 10 minutes on a much reduced light output. So, if I'm right that's a 24% decrease from the official spec of 2.4 hrs, or 17% if you add in the 10 minutes.

2. High Mode: 4 hrs and 15 minutes. That's a 6% increase from the spec of 5 hrs.

3. Medium Mode: 5 hrs and 50 minutes and then another 10 minutes to drop to moon mode. I'll make that an even 6 hrs for the calculation. That's a whopping 43% drop from the official spec of 10.5 hrs.

So, it's clear I need to get a lux meter to make my readings more accurate, I know. However, this is the third time I've tested this flashlight on medium. The other two runs were with Targus 2500 mah batteries. There might have been some conditioning or other battery issues there and those runs came in at about 5 1/2 hrs. So, with the Duracells, the run times were slightly longer, but far short of the official spec time of 10.5 hrs--same batteries used for the tests on high and turbo.

So, what gives here? The high run time was excellent, the turbo run time was off, but only around 20%, but the medium run time is way off. What should cause this? The light ran warm on turbo (I gather this is normal), but the light output seems ballpark and excellent. Why would Chevrofreak get 11 hours, but I can't? I can't believe there something wrong with the light, but..? Any suggestions?

I ordered both an L1D and L2D - CE last week and they should arrive tomorrow.. When I read the runtimes, I always look at those as best case scenario. For me that means using the best power source, Lithium batteries with high capacity NIMh as 2nd best source and alkalines as last choice.. I have both 2500 nexcell cells and 2650 duracells and will also do a runtime tomorrow when I get them..