Fenix LD10 runtime

[Egsise]

I can't find any Eneloop runtime charts of Fenix LD10, help..?

I just bought eight Sony Cycle Energy Blue LSD cells, discharged them to 1,05V @350mA, recharged 12h @260mA.
These are not rebranded Eneloops, see this post.
I tested the runtime of Fenix E20 with these cells, 2h 38min to the same brightness as LD10 medium(47 lumens), at 2h 56min it was at the same level as LD10 on low(9 lumens).
Very similar runtime as with Eneloops, like in here.

So why do i get only 1h or so runtime with LD10 using these cells, after 58min the regulation turns off and the light dims under 47lumens setting in a few minutes.

Faulty LD10, crappy cells, or is that short runtime normal with non-Eneloop LSD cells?

 

[Egsise]

Anyone?

Did some testing and since i don't own a light meter these are just estimations i got.

Fenix LD10 Q5
Sony Cycle Energy Blue 2000mAh
From 100% output to 50%

Turbo 60 minutes
High 95 minutes
Med 280 minutes
Low 1200 minutes

 

[Egsise]

Quote from LD20/L2D thread

I have done a runtime test on low on the L1D-CE and the LD10. Since they are the same heads, it should give some idea of the 2XAA runtimes.

I used two fresh off the charger Eneloops. I then recharged both cells and swapped them in the two lights and averaged the runtimes for each light.

L1D-CE - 22 hours 3 min
LD10 - 28 hours 30 min

I have no way of measuring light output so I guessed at 50% output. The LD10 dies very fast after it starts to dim.

 

[Woods Walker]

Those batteries are listed as 2000mAh. The Fenix runtimes are based on 2700 mAh NiMH. However you are better off using the 2000 mAh LSD batteries in my view.

 

[Egsise]

Those batteries are listed as 2000mAh. The Fenix runtimes are based on 2700 mAh NiMH. However you are better off using the 2000 mAh LSD batteries in my view.

Erm, right.
Are you saying that using 2700mAh batteries i would get 34h runtime on low?
Now i get 20h runtime with 2000mAh and it's normal?
Could you please do runtime tests with your LD10?

 

[JWP_EE]

I don't know about the LD10, but the LD20 runtimes are based on 2500 mAh cells.

 

[Woods Walker]

Erm, right.
Are you saying that using 2700mAh batteries i would get 34h runtime on low?
Now i get 20h runtime with 2000mAh and it's normal?
Could you please do runtime tests with your LD10?

Never did any tests but my L2D runs less with lower NiMH LSD batteries compared to standard 2450 and 2600 right off the charger. I remember someone with just the same questions about a Zebralight H50. Maybe that is the place I got the 2700 mAh as the company uses these for their runtimes. In any case the 2000 mAh LSD was found to be the issue with the less runtime however other factors with these batteries more than make up for this.

 

[Egsise]

I'm talking about the newer 1xAA LD10, not 2xAA L2D.

 

[GregU2]

I did a runtime test on my LD10 on low with just a Rayovac alkaline. I ran it a 4 or 5 hours a day for a total of 55 hours. Crazy huh?

 

[Woods Walker]

I'm talking about the newer 1xAA LD10, not 2xAA L2D.

Same idea I think. A lower mAh battery has less runtime than a higher mAh battery one cell or two unless I am mistaken.

 

[Egsise]

Same idea I think. A lower mAh battery has less runtime than a higher mAh battery one cell or two unless I am mistaken.

Well, do some math.
I get 20h on low with 2000mAh NiMH.
Manufacturer claims 34h on low with 2500(or 2700mAh) NiMH.
I should get 25-27h runtime with 2000mAh, right?

I tested my cells with E20 and i get the same runtimes what people get with 2000mAh eneloops, so i don't think the cells are the problem.

I can't find any runtime charts for LD10, thats why i started this thread.

 

[Egsise]

I think i found explanation....Vf variation.
http://www.candlepowerforums.com/vb/showthread.php?p=2677968#post2677968

It appears to be an issue of Vf variability - Edgetac believes I have a sample with very low Vf, causing it to run at higher drive currents (and therefore depleting the battery faster).

http://candlepowerforums.com/vb/showthread.php?p=834054#post834054

LED brightness is determined by the current flowing through the LED. Vf can affect it slightly, as a higher Vf means the LED is dissipating more power at the junction. More power dissipation means a hotter junction, and a hotter junction produces less photons given the same current flowing across the junction. In addition, all things being equal, a lower Vf LED requires less power (when using a switching converter), and will be slightly more efficient.

Ummm, wat?
Low Vf low runtime, or high Vf low runtime?

 

[Egsise]

If LED Vf(forward voltage) is higher than average, then runtime is shorter than average.
Right?

 

[Egsise]

Could it be possible that Fenix LD10 runtime is calculated.... with error in battery voltage.
http://www.kenworster.com/ledcalc/

PD20 has the same head, so same calculations with 3V CR123

LD10 on low 9 lumens 34h runtime(runtime from manufacturer)

Now this is what i measured as runtime on low, 20h

Ignorance is a bliss.

 

[Woods Walker]

Interesting calculation sheet. Also some 2000 mAh batteries can be 1800-2100 mAh,

 

[2manybikes]

Interesting calculation sheet. Also some 2000 mAh batteries can be 1800-2100 mAh,

And they need a few cycles to reach maximum capacity too.

 

[Egsise]

And under 2amp load 2000mAh NiMH gives only about 1850mA.

 

[Gunner12]

The converter is less then 90% efficient.
At 31 mA the LED is around 2.8 V, at 700 mA the LED is 3.4-3.5v(numbers from this post). Of course not all LEDs are like that.
From what I read CR123s are 1300-1500 mA.

Is it 20 hours to 50%?

There could be some gunk on the contacts that is sucking up some of the power.

 

[Egsise]

The converter is less then 90% efficient.
At 31 mA the LED is around 2.8 V, at 700 mA the LED is 3.4-3.5v(numbers from this post). Of course not all LEDs are like that.
From what I read CR123s are 1300-1500 mA.

Is it 20 hours to 50%?

There could be some gunk on the contacts that is sucking up some of the power.

Yes it is to ~50%

Ok, is 80% efficiency more accurate?

Like this

 

[2manybikes]

And under 2amp load 2000mAh NiMH gives only about 1850mA.

My new 2000mah eneloops are only about 1900 with no load. So go down from there with a load. How many times have you cycled them? 10 times would be a good start.