3 watts out of my Fenix L1P with Li-ion

I designed a circuit that is compact enough to fit in the Fenix L1P to drive a 3 watt Luxeon. It won't deplete the cell pass 2.5 volts and has a run time of around 1 hour per charge. It doesn't have perfect current regulation, but it is pretty good. I will post comparisions as soon as I get the second Fenix for my wife. This thing was a literal pain to get apart because of the thread lock they used. Does anyone have a suggestion for softening the thread lock? I tried heat but I still had some trouble.

Fenix mod thread here:

https://www.candlepowerforums.com/threads/92114

So... my question still, if I replace the emitter with a TY0K (the only bare T-bin I have at the momen) and run a 14500 in it with the stock circuit, will that kill the cicruit? Will it send a good bit of current and voltage through to the emitter?

Basically, I have no problems swapping emitters and whatnot, but I don't know anything about replacing or modifying circuitry.

Also, I'm happy with my L1P so I'd probably do this to a L1 2.0. Any problems seen with this?

If this is do-able, I'll get started.

I can't say for sure without trying, but my only concern is whether or not the schottky diode can handle the much higher current that a li-ion would put out. Great risk of killing it. I might try it out and get back with you. I wouldn't do it just yet if I were you.

cratz2 said:

So... my question still, if I replace the emitter with a TY0K (the only bare T-bin I have at the momen) and run a 14500 in it with the stock circuit, will that kill the cicruit? Will it send a good bit of current and voltage through to the emitter?

Click to expand...

With a 14500 source, you can remove circuit and let it run DD, resistored or with an LDO. The extra space can be used for additonal heat sinking/heat spreader.

Yeah, I could just try running it direct, but I'm not very handy with fabrication so taking up that extra space would be more difficult than the rest of the mod...

cratz2 said:

Yeah, I could just try running it direct, but I'm not very handy with fabrication so taking up that extra space would be more difficult than the rest of the mod...

Click to expand...

Maybe you can use crushed/crumpled aluminum foil. :naughty:

The stock heat sink of the fenix might not be enough to handle 3w so it's something to consider...

On the spacer - I was thinking a few really small washers soldered together.

on the heatsink - Yeah, but I'm sure it would turn into a 'wow light' for very short runtimes rather than a light that would actually see much use.

Either way, thanks for the heads up and the warning.

With direct drive you will get a steep current drop through the discharge of the li-ion and will not be able to use the full capacity of the cell. A buck/boost circuit is ideal. With my current setup, I get about an hour of run time per charge.

MillerMods said:

With direct drive you will get a steep current drop through the discharge of the li-ion and will not be able to use the full capacity of the cell. A buck/boost circuit is ideal. With my current setup, I get about an hour of run time per charge.

Click to expand...

Agreed. I installed a wiz2 set at 530ma. I think this is the ideal
current/runtime. It gets quite warm when left on the table for
extended times but never too hot to hold. Also, a 750mah AA runs it
for exactly 90 minutes!

New avatar?

Wow... when we can get UW0J/Ks for a reasonable price, that would be sweet as H E double hockey sticks with a 530!

Any chance you will offer modded Fenix lights on an as-ordered basis?

For now though, I'll just stick with my stock light.

I have a tool that can open these babies with little effort. I will sell them modified if anyone is interested.

would you post a pic of your tool please?

I'm sorry, I meant sell modified Fenix L1P's not the tool.

OK... so just for a ballpark price... For the modified light with your circuit for use with a LiON and, say, a TW0x emitter. What are we talking here if I send you might light - I'd probably want to use my silver L1? No cells required.

And I'd be glad to get the first one on the 'free beta tester' plan!

You still there?

What kind of price would you be thinking for a Lux III mod if we supply the Fenix host and an emitter.

I'd try it, but I'd rather you kill my light than me kill my light!

MillerMods said:

I'm sorry, I meant sell modified Fenix L1P's not the tool.

Click to expand...

not wanting to buy your tool. only want to see a picture of what you are using to take apart without damage.