Nitecore D10 mod: Does this make sense?

[RedForest UK]

Sorry for a possibly stupid/uninformed question, but I've just modded my Nitecore D10 GDP from it's original GDP led to a Cree XP-E Q3 5A led. Anyway, now having run a few runtime and current draw tests the runtime has dropped from 1hr15mins to about 45/50mins before the current starts to drop quite fast.

My question is, as the driver remains the same, so I would assume the nominal current draw should also be the same, can anyone explain to me why I am getting reduced runtimes? :thinking:

 

[VidPro]

what battery?

 

[RedForest UK]

A Sanyo Eneloop, both before and after.

 

[VidPro]

http://www.candlepowerforums.com/vb/showthread.php?t=206986

???
slight variation in the Vf of the led is all i can come up with.

hows it look :grin2:

 

[Mr Happy]

My question is, as the driver remains the same, so I would assume the nominal current draw should also be the same, can anyone explain to me why I am getting reduced runtimes? :thinking:

The likelihood is that the driver and original emitter were a matched pair in the design. When you substituted a different emitter you changed the design parameters and upset the system.

You may be assuming that the driver would act as a perfect constant current source, but there is no reason to believe this is the case. You were sold a complete light as a whole item, not a Lego kit.

If the light is brighter now than it was you have gained something in return for the shorter run time. (There's a danger you might burn out the driver perhaps, but that is the risk you take with modifications.)

 

[RedForest UK]

Okay then, thanks guys. I had considered a variation in the vf of the led but in all honesty I'm still not entirely sure about how that works anyway so I just thought I'd ask the experts. ;)

It was pretty stressful taking apart one of my first and very favourite lights, especially as the wires were quite a bit on the short side.. and while the led isnt quite centered the beam profile is as beautiful as ever and the tint is just amazing. :thumbsup:

I think that I may have gained some brightness, though I obviously never had both versions at the same time to compare and I dont have any equipment for measuring the output digitally. It definately didnt lose any output anyway which is good for a warm tinted emitter. It throws quite a bit further now as well.

I hope what you say about driving it out of spec doesnt apply in this case and that I don't damage the circuit at all.. :confused: I'm hoping that as the D10's have a very versatile driver anyway, which is able to accept a broad voltage range, then on eneloops I shouldnt be able to do it any harm.

I did do a runtime test on 14500 btw, and at start up it was as bright as my TK20 on high, which is 150lumens! It quickly tailed off to about 110lumens or so I'd say though..

On the whole I'm very pleased with the mod, I just hope it holds up quality and reliability wise as well as it would have before. :rolleyes: