Help with dive light mod to LED...

Ok so this is my second post on the forum. Hopefully this is posted in the correct place the post covers a number of spots form the forum.

I have been reading about making flashlights for few weeks now. I am currently building a high power LED Dive light and got the great idea to modify an existing light of mine.

The light is a Pelican Nemo 4300, it uses 8 C cell batteries (I use 8 rechargeable NiMh C cells 1.2V) and powers a Xenon bulb to about 270 lumins. I want about 500 lumins out of the light when all is done. (http://www.opticsplanet.net/pelican-nemo-flashlight-4300b-black.html)

I was thinking of modifying it to have a 3x Cree XRE R2 Led's but the voltage of rechargeable batteries is a little lacking. I am assumng i will need a boost kit, but i do not know what that will do to battery life and light output.

I think this kit will do http://www.cutter.com.au/proddetail.php?prod=cut756

With this reflector http://www.dealextreme.com/details.dx/sku.11922


What do you guys think I should get for light output and battery life?

Thanks Brian

My buddy has the light and he is very disappointed with it. He has only ever used it with primarys and I think they may not supply the needed current. Have you noticed a difference between primarys and NiMhs?

The light has quite a large reflector and it would be a shame to not make use of it. I would look at a P7 (or MC-E) with the stock reflector although this may not work to well.
If you go for 4 LEDs instead of 3 you could wire them 2P2S with a Vf of about 7.4v so your stock battery configuration will be close enough to use with a Kai Domain P7 driver. I use this set up in my cannister light.

Heat will be your biggest worry. With no thermal escape the inside may get quite toasty. Perhaps run 3 or 4 LEDs in parallel from a P7 driver with the biggest heat sink you can fit inside.

Everything i put NiMh's in has worked a little better. These lights are not an exception.

I'm not to worried about not using the reflector, and I am only going to use 3 LED's with Cree's heat sink. Being in the water hopefully heat sinking through the ABS plastic will be better than in air.

Will the boost driver hurt my battery life that much?

I have this light too. And i use it a lot. I have thought about giving it an upgrade but the more i think about it the more i think its no possible.

The problems are that every single part is plastic or rubber, the reflector is only good for a single Led and the bulb is currently mounted directly on the batter pack with no space for anything else.

If you figure it all out though the Osram Ostar might be a good choice, and please let me know how you do it...

CBR-runner said:

Everything i put NiMh's in has worked a little better. These lights are not an exception.

I'm not to worried about not using the reflector, and I am only going to use 3 LED's with Cree's heat sink. Being in the water hopefully heat sinking through the ABS plastic will be better than in air.

Will the boost driver hurt my battery life that much?

Click to expand...

I think you will find that the heat sinking will be much worse as it is trapped inside the plastic and will have no flow and plastic is a very bad conductor of heat. My guess is that heat sink will work for shot runs but the LEDs will soon over heat and die. I'd go with 4 LEDs and under drive them with a much larger heatsink. Also that LED package is MR11 style (35mm) where the reflector is MR16 (50mm) so will probably not work together.
As long as you use a efficent boost driver you shouldnt have a problem.

I understand that heat sinking maybe a problem. That is something I will have to come up with a solution for. I will use the 50mm set up so the larger reflector will work.

As far as everything being molded that maybe helpful for mounting the electronics and a larger heatsink. Just apply a dremmel and JB weld until it works.

I'll let you know how things go.

I am just trying to get the battery and driver setup before I go hacking up a $50 light. Will that setup give me at least 2 hours of battery life and better than 400 lumins?

Yeah I think 2 hours and 400 lumen is a reasonable goal. Mind you I still think you should consider a P7 with the stock reflector and if that does not work then get the 50mm P7 reflector. The P7 is good for up to 900 lumen but if you under drive it you will get longer batter life and less heat build up.

Think in terms of what you can do with 5 watts. If that is not enough light, consider an incan bulb upgrade.

Where can I get a P7 and a driver for it? This may actually be the way to go with the setup of the light internals.

Dealextreme should do most of the parts you need, a P7 would be great with the stock Nemo reflector.

If you pull this off, i would like to know exactly how you did it, so i can do it to. Cheers.

gav6280 said:

Dealextreme should do most of the parts you need, a P7 would be great with the stock Nemo reflector.

If you pull this off, i would like to know exactly how you did it, so i can do it to. Cheers.

Click to expand...

I'm working on the heat sink right now. I'm thinking it needs distance and surface area for this to be successful. I have some sheet aluminum so we will see.

Gonna get this p7 (http://www.dealextreme.com/details.dx/sku.12721)

I was thinking about this driver (http://theledguy.chainreactionweb.com/product_info.php?cPath=48_49_61&products_id=1006) will that do the trick?

Does anyone know how to make this a one mode driver, or how to switch between modes with a magnetic switch? :candle:

http://www.kaidomain.com/ProductDetails.aspx?ProductId=6282

-or- i guess i could just uses this driver

http://www.kaidomain.com/ProductDetails.aspx?ProductId=1770


One of these should be the answer to the driver problem. Next time to get parts and rebuild the flashlight. :twothumbs

I would go for the cheap 7135 based driver as many people have reported overheating issues with the other one.
The driver will work great if you wire your batteries parallel in pairs and place 4 pairs in series. (or 2 strings of 4) so you get about 4,8V fully charged.

Cant you use the switch already in the flashlight? You change mode by quickly turning the light off and on.

thanks for the heads up in the drivers:wave:

The battery is wired in series I'm going to have to rewire it.

The flashlight has a magnetic switch already built in to maintain water tight integrity. Not sure how it works yet.

Well I have some pics and measurements for my Nemo C8 dive light to Led conversion.

The depth of the reflector is going to make it impossable to heatsink the P7 and keep the stock reflector. I ordered this one form dx (http://www.dealextreme.com/details.dx/sku.12229) hopefully it works well.








This is the battery holder and lamp holder. It looks like I need an aluminum plate about 62mm in diameter by about 3 or 4 mm thick for a heat sink. plus a small relief for the old bulb holder.





Reed Switch

"I wish I didn't have to take everything apart"

But that's what this forum is all about! However, the "oops" is probably the most accurate prediction. I have just begun a similar mod of a Pelican King Lite 8D and have similar feelings of trepidation. I will be converting to nimh sub-c cells as I have a pile of them as well as several chargers. I can fit at least 4 possibly even 5- 5cell packs in the body. The main switch has two on positions so I might set it up as two lights in one housing(one spot, one flood). Cutter has a nice 6-up pcb will fit easily or I can go for the cram-job(I favor the cram -job). I never liked the spot on any of the Pelican lights I have especiallly as in diving most times I'm pointing it at something only a few feet away so my optics will favor spill rather than throw. Good luck.

What about this complete set from DX. I used this for my first mod with a good result. Complete P7 with reflector and heat sink. Very easy to install if it fits?
http://www.dealextreme.com/details.dx/sku.14413

My mod:
https://www.candlepowerforums.com/posts/2724888

thanks for the input.

the premade unit is to big for the light. i think the light with 1 P7 is better than the 270 lm it makes now. Latter i may do a 3 p7 mag canister light.

Well I went with the P7 Driver from Dr Wichtel (A CPF member). it looks good. My P7 is still in china at DX maybe i'll get it some day.

Once the heat sink and P7 get here it should be an easy build. :twothumbs

Pics of SSC P7 Buck driver. Nice craftsmanship (Gets yours here: https://www.candlepowerforums.com/threads/201981)

Got my P7 in the mail today . Heat sink should be here this weekend!:green: