Fenix L1 5 Watt mod

I've modified a Gerber Infinity and an MXDL using a raw lithium ion cell and a circuit that I designed to drive a 5 watt luxeon in the past. I sold the MXDL and got slightly less for it on ebay than it cost me to make it (The customer was very pleased and has continued to keep in touch with me, asking when I will make him a modified Gerber, he says he always carries the MXDL in his police bag). I kept my modified Gerber and went on my merry way, discouraged that there wasn't more interest in the MXDL mod. I have a feeling the host I chose was more to blame for the lack of interest. Although I haven't recieved my Fenix L1 yet, I know this flashlight will make a superb 5 watt host. 5 Watts is alot of heat to dissipate I know, but the Gerber, although very tricky to pull off (mounting the Luxeon and polishing the bezel and nickel plating it! eek, too much work) it worked out O.K. but no hot spot, just mostly a flood task light and it does make a great hand warmer in the winter time! The Fenix is slightly longer and the same diameter as the Gerber, I can't wait to mod the Fenix, it will be a perfect match with it's reflector. The larger LED chip in the 5 watt Luxeon will give a hot spot that is much larger than the 1 watt. I just want to see if anyone is interested or has any questions.

Cool!

Have you seen this thread? You might find it interesting:

https://www.candlepowerforums.com/threads/98900

That is interesting. My drive circuit peaks at 5 watts with a freshly charged Li-ion and will gradually desend for a half an hour and starts flashing when the battery gets below around 2 volts. A truely awesome amount of light for such a small flashlight. If it is a powerful tiny flashlight you want, I can bring it.

li-ion cells can sustain permanant damage from ONE severe discharge below 2.5V. for all practical purposes not much current delivered below 3.5V.

generally it's best not to go below 3V with li-ion cells.

I have used mine now for about 8 months I can say I have had no troubles. The rechargeable cells can be had for less than 4 bucks and will last for many charges in this application (I haven't ruined any) . I generally do not completely deplete the cells but I have found that before the cell reaches a critical low the circuit has trouble sustaining the output, hint time to change the battery. And yes, the light output curve is not the best but very good for about 20 to 25 minutes. I have to say, what could we expect? I do find it is fun and impressive. It's a give and take game no matter what you try to accomplish when trying new and radical things. Certainly a 3 watt Luxeon would be more practical, and I could go that direction too.

Luxeon III is probably the next logical step for the Fenix L1/L2.

I agree, in fact I believe it would be much more practical. Does anyone have suggestions for what circuit would be best if you are trying to use a Li-ion cell to drive a 3 watt in the L1? A buck-boost circuit would be best as it would step down then step up the voltage of the Li-ion. The trouble is finding an integrated circuit with a internal power switch that will handle the current.

Its been done here

http://candlepowerforums.com/vb/showthread.php?t=88649