# Green LED fishing light



## bosts1

Hi guys, new to the forum here. I am about to start a project I have been wanting to do for a while. I am going to build an underwater led light. I want it to be really bright and green in color to draw in bait fish and stripers on our lake. I and considering using luxeon star leds in green with a 40 degree lens, and driver from them and heatsinks. Now my main question now is if i build this with heatsinks and enclose it in a acrylic box like a tiny aquarium and it is always underwater when its on will the leds get to hot? I dont know how the guys that sell these leds actually cool them down. Also if anyone has any advice on this project I would greatly appreciate it.


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## fyrstormer

Luxeon is way old now. There are much newer LEDs available nowadays. Cree is a popular brand.

Buy some heatsinks, cut holes in the acrylic box so the heatsink fins can stick into the water, seal them in-place with epoxy, and attach the LEDs to the heatsinks. The water will provide all the cooling you'll ever need.


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## bosts1

fyrstormer said:


> Luxeon is way old now. There are much newer LEDs available nowadays. Cree is a popular brand.
> 
> Buy some heatsinks, cut holes in the acrylic box so the heatsink fins can stick into the water, seal them in-place with epoxy, and attach the LEDs to the heatsinks. The water will provide all the cooling you'll ever need.



I am wondering how these guys that sell these underwater lights do it without having them overheat. They are enclosed in sealed plastic enclosures no fins sticking out anywhere. You think they are just counting on the leds to die early but still last 20 years or so?


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## jspeybro

Hi,

have a look in the dive light section. I suggest making or modifying a metal housing instead of a plastic housing. When we make dive lights, we tend to use the leds at full power. The only thing we need to do is make a thermal path from the led to the water and you'll have an entire lake as your heatsink. You don't even need fins on your heatsink.

typically we we use some kind of existing flashlight/divelight body, make a heatsink which is nothing more than some round pieace of aluminium that nicely fits into the housing so it makes as much contact with the housing as possible so the heat can be transferred to the housing. The contact between the housing and the water is more than enough to keep the LED within its limits.

Johan


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## jspeybro

bosts1 said:


> I am wondering how these guys that sell these underwater lights do it without having them overheat. They are enclosed in sealed plastic enclosures no fins sticking out anywhere. You think they are just counting on the leds to die early but still last 20 years or so?


as long as you don't drive them too hard, and your heatsink is reasonably big, you'll be fine in a plastic housing. in divelights, a single cree xre or xpg is about the maximum you can use in a plastic housing. using cree XML, MCE or other >5W leds need better heatsinking. If you look closer to existing lights, you'll notice that these lights typically use cree XRE leds or older leds.


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## bosts1

Thanks. I am still trying to figure out what to use. I want a super bright green or even white light. I am noticing I can get more lumens out of white. But I am trying to figure out how to maximize the lumens I can push from this idea. I want something I count mount underwater on my boat that will really shine deep and bright to draw bait up into the lights. So any other ideas are greatly appreciaited. Thanks guys!


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## jspeybro

sounds like you want a high power led with an aspheric lens since these are best capable of focussing the light to a tight beam. 
Any particular reason why you want green light? The shorter the wavelength, the faster it gets absorbed by the water. in theory, red leds should work best. It is difficult to compare the output of color leds and white leds since the power of color leds is usually given in watt while that of white leds is given in lumens.

If it is just under a boat, (not deep in the water) you may be fine with a standard maglite as a housing. there are many heatsinks available to install leds in these housings, but you'll need to figure something out regarding the aspheric. Keep in mind that the aspheric should not be in contact with the water but behind a flat lens, or your led will not be in the right position when you focus it above the water.
For diving, we also use maglites and typically replace the o-rings for ones that are 1 size thicker to improve the water tightness up to tens of meters suitable for diving. for diving, we do however change the switch mechanism, but you may be fine if it's just under a boat.

johan


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## Lips

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Hard to beat the Green Florescent version at Academy Sports for *$16* for the magnum version. Put some silicon around ends to help with factory seal if submersing... 

It only draws 1 amp and puts out a ton of light. My fishing partners "humor" me when it comes to lights of any kind!

I have the incandescent version and it's neutral white light with much more amp draw (5 amps or so)




















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## bosts1

jspeybro said:


> as long as you don't drive them too hard, and your heatsink is reasonably big, you'll be fine in a plastic housing. in divelights, a single cree xre or xpg is about the maximum you can use in a plastic housing. using cree XML, MCE or other >5W leds need better heatsinking. If you look closer to existing lights, you'll notice that these lights typically use cree XRE leds or older leds.



maybe instead of going for these highpower leds that get so hot I just should dial it back to so some panels of leds that wont get to hot? such as this


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## captainr

I personally use Total Aquaglows light it has built in heat dissipation and uses LED's so over heating isn't a issue. I have had it for about 6 months with no issues.


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