Problems with my Fenix LD10

Hello,

I own about 10 flashlights. I wanted to buy a better quality AA flashlight that is digitally regulated so the brightness stays constant as the battery weakens. Seeing that the Fenix LD10 is digitally regulated, I bought it. The problem is, that as the battery weakens, the light dims. Even on turbo mode (100 lumens) it drops to about 5 lumens. Also, on anything but a new battery, when I soft click the button to select a different mode, it shuts off. I have contacted Fenix support, but I am getting no where. They just tell me that my light is not defective. They say that the light will normally dim as the battery weakens. As to the mode change shutting it off, they just instruct me as to how to change modes (not a big help). I own the Fenix PD30 and have had no issues with it. I have also done a fair amount of reading on the forums and it seems that Fenix is highly thought of. Here is my take on this. Using the description that Fenix gives for the light "Digitally regulated for constant brightness" To me, this means the light intensity stays constant and will not dim. I find it frustrating that Fenix support just keeps insisting that my light is not defective. Any advice? thanks.

Most lights that say regulated actually seem to dim a bit as the battery runs down, though not usually as badly as the old incans. With multi-mode lights, you usually lose the upper levels first.
Since you seem to be new here, a couple of points you may not be aware of - you do say you've done a fair bit of reading so apologies if you are already clued up on batteries, etc.....

Your choice of battery (cell actually) is important. High-powered LED lights do not perform well on alkaline cells due to the cell's high internal resistance. Alkalines are also prone to leakage in high-drain applications. Pretty much everyone here will advise you to use high quality NiMH brands such as Sanyo Eneloop or Maha Imedion.

As your cell "weakens" the effect on your light will depend on whether it is an alkaline or NiMH. An alkaline will normally give a gradual decline (starting with a loss of high modes) whereas NiMh will hold their output much longer, but with a much faster drop-off at the end. If the cell is really weak, the light may turn on momentarily at a low level when the cell has had time to "recover" a little after being off for a few minutes. But when you try to ramp up the output, the voltage sags to the point where the light just shuts off again. However, this would have to be a really dead or bad quality cell.

Can you give us some more info about what type of cells you are using in this light? If they are rechargeables, what type of charger are you using?

FYI, I purchased a MAHA C9000 charger/analyser last year and was amazed (horrified) at how many of my old NiMH cells were cactus. After throwing most of them away (or relegating them to use in non-critical, low drain devices) and stocking up on Eneloops/Imedions I haven't looked back. Short runtimes and dodgy behaviour are pretty much gone for all of my devices.

Lastly, I'm not denying there may be something wrong with your Fenix light, but I'd be checking your power source first and foremost.

Can you take the light back to the dealer you bought it from or did you get it online? I recently had issues with a Fenix MC11, which the dealer in HK eventually refunded me for after about 3 months of email exchanges, but Fenix themselves were worse than useless in helping me deal with my problem. I just could not get a straight, clear answer from them, nor could my dealer. So I sympathise with your frustration mate. I know people here think of Fenix highly, but their support didn't impress me either.

Hope some of this may help.
Trev

Thank you Trev for your extensive, thorough reply. I was able to follow your reply and understand your thoughts on this matter. To answer your question about batteries, I am using Rayovac (non-rechargable) alkalines. I understand that alkalines are a far cry from NiMH. I do in fact own some, I just have not tried them yet. For reasons of supply, I was planning on using this light exclusively on AA alkalines. I think the real issue here is that Fenix states "digitally regulated, constant brightness" and I was expecting the light to stay full brightness until the battery no longer can satisfy the current load requirement. When the light on turbo mode is down to about 5 lumens, the battery measures just under 1 volt. I have read reviews that seemed to support this impression I have that this light would maintain full brightness until it finally shuts off. I bought the light at http://www.fenix-store.com/. I was thinking that this was direct from Fenix themselves. I will (embarrassingly) admit that most of the lights I own are from dealextreme.com , and I am hoping to move to a better quality light and thought this would work out better. I use it for commuting on my bike. When it is bright, it is more than adequate. Now, the E05 that came with it stopped working altogether. I, like you are less than happy with Fenix support so far. I am now leaning toward 4Seven for my next flashlight.

thanks again!

pmwoodward said:

Also, on anything but a new battery, when I soft click the button to select a different mode, it shuts off.

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When you want to change the mode, KEEP PRESSING the tail switch softly (do not click it down to much) untill you see the output has been changed.
Hope this would help too.
As for the regulated problem, can't agree Trevtrain any more. I think you don't want you flashlight shut down suddenly when the battery is drained out and leave you in completely darkness.

As previously stated, different battery chemistries makes an incredible difference in the performance of flashlights. If you could give us a little more information on the battery including: brand, chemistry, and age. After gaining a little more knowledge it will be easier to trouble shoot.

An aside note on regulated lights; lights with good regulation will maintain a constant level of light within any given setting so long as there is enough remaining power in the battery to sustain that level of output. If the battery does not have enough power the light will drop to the next level that the battery can sustain. I have no problem maintaining a constant level of brightness on my Fenix lights when I use high quality batteries in them. Lower quality batteries or improper chemistries will cause the light to drop the the next mode that the battery can maintain.

Just because a light is regulated does not mean output is totally flat.

Some lights have perfectly flat regulation that maintain the same output for most of the battery charge (Zebralights); some Shiningbeam drivers. But other "regulated" lights like Fenix actually see a considerable dimming of output as the battery winds down. Regulated just means there is an electronicdriver that is controlling how much current is delivered from the battery to the LED.

pmwoodward said:

Thank you Trev for your extensive, thorough reply. I was able to follow your reply and understand your thoughts on this matter. To answer your question about batteries, I am using Rayovac (non-rechargable) alkalines. I understand that alkalines are a far cry from NiMH. I do in fact own some, I just have not tried them yet. For reasons of supply, I was planning on using this light exclusively on AA alkalines. I think the real issue here is that Fenix states "digitally regulated, constant brightness" and I was expecting the light to stay full brightness until the battery no longer can satisfy the current load requirement. When the light on turbo mode is down to about 5 lumens, the battery measures just under 1 volt. I have read reviews that seemed to support this impression I have that this light would maintain full brightness until it finally shuts off. I bought the light at http://www.fenix-store.com/. I was thinking that this was direct from Fenix themselves. I will (embarrassingly) admit that most of the lights I own are from dealextreme.com , and I am hoping to move to a better quality light and thought this would work out better. I use it for commuting on my bike. When it is bright, it is more than adequate. Now, the E05 that came with it stopped working altogether. I, like you are less than happy with Fenix support so far. I am now leaning toward 4Seven for my next flashlight. thanks again!

Click to expand...

I think you will find that 4-7 lights would fail just as spectacularly on max if you tried to use alkalines with it. If you want to use the higher modes, you will have to ditch those terrible alkaline batteries. This is not negotiable.

Fireclaw18 said:

Just because a light is regulated does not mean output is totally flat. Some lights have perfectly flat regulation that maintain the same output for most of the battery charge (Zebralights); some Shiningbeam drivers. But other "regulated" lights like Fenix actually see a considerable dimming of output as the battery winds down. Regulated just means there is an electronicdriver that is controlling how much current is delivered from the battery to the LED.

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True but if you have a look at the graphs here the problem is obviously the alkaline batteries. The Fenix has almost perfectly flat output until the battery is almost dead (on Eneloops).

Alkalines sucks, thats just the plain truth. Use eneloops or energizer lithium L91's

Well, you may have just answered the query OP. Your Rayovac alkalines are most likely the culprit here. You say they measure 1V when Turbo mode is down to 5 lumens; I'm thinking there are two things to consider:

1. Turbo mode would obviously not be a true turbo mode at 5 lumens - as SimulatedZero said, most regulated lights "step down" to lower levels when the cell can no longer keep up. Even if you could change modes, you'd see no difference in light output. At least, this is the way it works for my Fenix and Zebralight lights. I lose the high modes first until finally only low works. Attempts to change modes at this time result in a slight "blink" but no increase in output. Perfectly flat regulation with a sudden cut-off is very rare, as pointed out by Fireclaw. I think my Predator offers this option but it is not usually something you want anyway, especially on a bike.

2. The 1Volt you measured - was this under load or just by putting a multimeter to the terminals? The cell may well measure 1V open-circuit, but would fall drastically when loaded, even to the point where the light just shuts off.

Bite the bullet and get a four-pack of eneloops. Watch the standard "kit" charger though as it may be a simple timer-based unit. Most of the "kits" sold down under here have that useless crappy thing which only charges 2 or 4 at a time. Sanyo do make "proper" chargers with -DeltaV and temperature sensing so look for one of these. Actually, there is a nice little Eneloop USB charger with independent channels for charging one or two cells at a time and following the proper charging routine. I have a couple - they are very handy.

As for support, I'm sorry to hear your E05 is also playing up. The Fenix stuff is usually well-regarded for quality and my LD01 and E01 have been faultless. In general, they would normally be a better bet than your DX lights. If you get no help from Fenix, try contacting the dealer. This is what they told me to when I initially emailed them, along with more or less saying I should have bought from a local supplier anyway.

But really, try some better battieris first.

Forgot to say, after you use a proper battery (eneloop or L91) and if you still have the same problems then contact the fenix-store. Top of the page is "Warranty Info" click that and read

Trevtrain said:

2. The 1Volt you measured - was this under load or just by putting a multimeter to the terminals? The cell may well measure 1V open-circuit, but would fall drastically when loaded, even to the point where the light just shuts off.

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This is quite right. it is a common mistake easily made by the people who didn't know it before.
And I think it is better to contact the dealer at first but not Fenix when you got the problem with your light. A nice dealer would take care your problems and maybe you won't contact Fenix directly at all at last. Anyway, they are just too far way. As far as I know, fenix-store is a nice dearler, too.

I have only used NiMH batteries in my Fenix lights and have not experienced the problems that you describe. As stated before, do your testing with a good set of batteries and try Customer Support again.

As far as the light dimming vs "regulated". I like to help explain a little.

To maintain constant brightness, you need to maintain the total output wattage. Let's say output at turbo mode is 3W. If the LED requires 3v to be lit up, it needs to draw 1A from the battery. As you keep the light on, the voltage of the battery keeps dropping. To maintain the same brightness, that means the current draw needs to keep going up as the voltage drops. However, there is a limiting factor that different batteries have different max current that it can output. Alkalines being worse than NiMh. When the voltage drops and the battery cannot spit out the additional current to maintain the same wattage, the light dims down. The regulation can keep increasing the current draw to maintain the brightness but if your battery cannot supply, there is not much the regulation can do. Therefore, if you start the light at medium or low, it will maintain that same brightness for a lot longer than you keep the light on high or turbo.

Am I making sense out of this?

I appreciate all of the replies. I believe that I have been sufficiently been brought up to speed. Based on what I now know, I would have to agree with Fenix support that the light is not defective. Although, I do think the "constant brightness" in the advertisement is a bit deceptive (at least to a rookie like me). I think it is only fair to say that Fenix support has not been poor as I previously mentioned. They were simplistically stating more of less the same thing stated by the replies on this thread. I will buy the enloops and start enjoying the true capabilities of the LD10. Thank you again, I look forward to learning a whole lot more on this forum.

Uh oh, got an LD10 from BladeHQ.com, was told to contact Fenix directly,, I am starting to feel like it was a mistake,, should've went with Sunwayman or Jetbeam.

pmwoodward said:

I appreciate all of the replies. I believe that I have been sufficiently been brought up to speed. Based on what I now know, I would have to agree with Fenix support that the light is not defective. Although, I do think the "constant brightness" in the advertisement is a bit deceptive (at least to a rookie like me). I think it is only fair to say that Fenix support has not been poor as I previously mentioned. They were simplistically stating more of less the same thing stated by the replies on this thread. I will buy the enloops and start enjoying the true capabilities of the LD10. Thank you again, I look forward to learning a whole lot more on this forum.

Click to expand...

constant brightness often drops (a little) on higher modes to let a person know when it's running down

your light might think the batteries are weaker than they are.. who knows


but in the future, if you want to just use alkalines stick to lights under 60 lumens




"Uh oh, got an LD10 from BladeHQ.com, was told to contact Fenix directly,, I am starting to feel like it was a mistake,, should've went with Sunwayman or Jetbeam."

Are their return policies different? I honestly don't know.

Ezeriel said:

but in the future, if you want to just use alkalines stick to lights under 60 lumens

Click to expand...

If you want to use alkaline just avoid turbo.
Medium and high is often enough and in an emergency when all you have is alkalines, well consider high or medium the most possible lumens available.

How do you disassemble a Fenix LD10 Bezel Head Assy?

pmwoodward said:

Hello,

I own about 10 flashlights. I wanted to buy a better quality AA flashlight that is digitally regulated so the brightness stays constant as the battery weakens. Seeing that the Fenix LD10 is digitally regulated, I bought it. The problem is, that as the battery weakens, the light dims. Even on turbo mode (100 lumens) it drops to about 5 lumens. Also, on anything but a new battery, when I soft click the button to select a different mode, it shuts off. I have contacted Fenix support, but I am getting no where. They just tell me that my light is not defective. They say that the light will normally dim as the battery weakens. As to the mode change shutting it off, they just instruct me as to how to change modes (not a big help). I own the Fenix PD30 and have had no issues with it. I have also done a fair amount of reading on the forums and it seems that Fenix is highly thought of. Here is my take on this. Using the description that Fenix gives for the light "Digitally regulated for constant brightness" To me, this means the light intensity stays constant and will not dim. I find it frustrating that Fenix support just keeps insisting that my light is not defective. Any advice? thanks.

Click to expand...

I bought the LD10 to use exclusively on AA alkalines - the cheapo industrial energizers that we buy in volume for work. I think yours is defective, mine works as it should through all modes even on a battery that's been on turbo for 30 minutes. The only time the LD10 has really shut off unexpectedly was when it's in 40 degree weather, but that's expected.