Hola, newbie here! If it’s not too much trouble I have a few questions, if someone has the spare time to answer them.
I want to use 1 or more xp-l hd emitters and make an underwater light. I plan on powering them with a 18650 3.7v 2600mAh ultrafire battery.
The voltage will vary from 3.7-4.2vdc so…
Would I need a driver for the LED? There will about 3-4’ of wire running from the battery to the bulb, so I’m thinking the length of the wire will diminish the voltage, thus no need for a driver.
The purpose of the lights is for floundering, I have made lights before with MR-16 bulbs and some cheap underwater led flood lights off fleabay.
I plan on potting the lights in some silicone for waterproofing and using a medium ripple lense.
Any advice or suggestions would be greatly appreciated, I am willing to build anything, I love this kind of stuff just ignorant with the electronics.
I have been reading for 2 days and have spoken to a CSR rep from a led supply house(that was not helpful)
I wouldn’t use that Ultrafire battery. Even my “3000mah” ultrafire battery only has 990 mah of capacity. So even when “Ultrafire” has a legit capacity written on the label, it’s STILL a lie.
What are you going to stuff the electronics into? What’s your host?
I don’t know what I will be putting them into or on yet. I was going to gather the electrical supplies first and then come up with something.
I do know that the light will be on the end of a stick of PVC and the battery pack will be in the handle with a switch.
LOL I have read a bunch of posts so I knew it would be a good idea to put the brand of battery I planned on using. I have another brand at home, when I get off work I will look and post the brand name. Thanks for the battery intel, I ordered them off ebay, from China, so I’m not surprised they aren’t as advertised. I have meters and will check the battery performance, but thanks for saving me a step!
I have a friend who owns a aluminium fabrication shop so I could swing by his shop and get a block and fabricate something to mount the drivers to.
I also have 2 sealed cell 7amp/hr batteries, that I use on my current lights. I just want some brighter lights, plus the ones I currently use are to white, 7000k, I plan on using the warm whites, 3000k. They work so much better if the water is stained or dirty.
I could use the batteries I currently have but I would definitely need a driver for them. If I were to go that route I was looking at a Mean Well LPC-60-1750 constant current driver…
I would just prefer to internalize the power source.
Hey mate find a host first then start from there.
Those cells are rubbish you could use your battery pack but it may be over the voltage limit of the driver.
You really do need a driver for those high powered leds. The light you buy from shops that plug straight into your car battery are running tail lights from a car so they are already 12 volts.
I love fishing! I dont even know if that is a real Cree XML2 i can not tell.
He doesn’t say he didn’t use a driver?
If i was you id just buy a diving light and attach it to a pole? Easier and cheaper. Main issue with this light is it cant be used above water its plastic so it has no heat sinking?
No current or voltage drivers are needed! What he mean by this is that you do not have to add your own to connect the battery compartment its got a built in driver.
I guess that is pretty vague “no current or voltage drivers are needed”
I’m not familiar with prawning or shrimping lights. I did google them and they look similar.
I have 4 lights ready to roll anytime I want to go floundering, so this is more or a “new hobby” I enjoy building things. This is an area I’ve only dabbled in, I can salder and fabricate things.
After I build some floundering lights I plan on using the gained knowledge to build some flashlights as well.
I can also use a square of heatsink and pot the leds in some 2 part silicone for waterproofing. Then attache the square to a pole with wires ran through. That’s another viable option.
What would you reccomed to power 2 or 3 of those emitters?
Hmmmm i am not sure flounder is found in sand so the more lumen the better but i would think two emitter would be enough. I am not sure why so many people use PVC to make these lights? Even prawning lights. Wouldn’t it be easier to just use an empty flashlight and build that? Like i get the part that it fits together easy but PVC wont last that long if put in salt water? I dont think you need to encapsulate the LEDs or driver if you use a normal flashlight they should be good for about 2 meters and diving lights are good well above that.
So you could use two LEDs or one super bright one? There will be a driver difference and you will have to set up the batteries different. depending on what emitter you want to use. If you do want to just use the Cree XPL if you run them on direct drive you could possibly get 3000 lumen total depending on heat sinking. The light would step down to 2200 lumen after a set time and keep on fading till the batteries are finished. Or you run them on a constant current driver they will not put out as much light but the battery will last longer and stay at a brighter for longer its a more linear way of draining the batteries.
Your in the USA? So probably mountain electronic would be the best place to get parts.
Don’t get me wrong it will be a straight forward build easy enough either route you go. You can easily change parts in the future.
You are correct flounder are found in the sand, mud, grass, and around rocks. PVC is typically used because it’s cheap, easy to customize, easy to obtain, and it lasts forever. Saltwater has no effect on the PVC. Your able to get just about any angle out of PVC and its waterproof. Underwater is the way to go, typically, it cuts down on the glare. Also if there are ripples on the water the light refracts off the ripples and you get a distorted vision.
You don’t usually gig in deep water, mostly waist deep or so, I like to be able to see deeper and further away from me. Hence the desire for a spot light, plus the spot will cast a shadow on the fish (they are a flat fish) the flood will help you line up your gig to stick the fish upclose.
I don’t mind more lumens, I was just under the impression that if I go to big than I will end up carrying a larger battery in my backpack(like I do now) I would ideally like to keep it all in one, so maybe a nicad battery or something to that effect?
For sheer output and weight its defiantly better to go lithium it will help keep the flashlight lighter. Seeing as you making the light you have so many options you can choose from.
I am thinking a battery holder like this. The size depends on you. You can buy from like 1-4 cells i think is common. This will give you 2 cells in parallel so basically 3.7 volts nominal but you get double the Mah rating so if you are using 2 3400mah 18650 you will have 6800 Mah total depending on what driver you driver you choose will determine the run time. Or you can go the route of using the PVC pipe as a battery holder then that would change the style of driver you use. https://www.fasttech.com/products/0/10002233/3884300-2-18650-battery-holder-case-w-lead-wires
Ideally you would want at least a 3amp+ driver with the 2 cell configurations that would give you about an hour of run time on high mode. That should be around 2000 lumen . plus you need a switch.
Yea mate no problem take your time and make a few decisions and let me know if you need further help. Obviously it depends on how much you want to spend also.
Most of boys on here that build triples use direct drives because if the driver puts out 9 amps in a parallel set up that will be shared by all the LEDs so 2 LEDs at 9 amps will be 2400 lumen easy. But if you do build it with direct drive and it doesn’t have enough cooling it will burn up! The water will help keep it cool but like if you keep out of water for to long it may break.
A driver like this would do the trick. I might try and build one of these my self in a few weeks. Http://www.mtnelectronics.com/index.php?route=product/product&product_id=480
First off I can see where this can be an addictive hobby, I’ve spent the last 3 days reading about LEDs, lol.
I have some cree flashlights that I had ordered a couple years ago off amazon and ebay, I thought they were bright until I started looking at these flashlights yall build on here. I am at work right now or I would have one taken apart. I plan on modding some of them now as soon as I get some new emmiters!!
I have some questions though about putting all of this together, if you know of a post already that kind of explains how to do all of this feel free to share. Something like a get started here guide to building lights would be awesome!
But my questions are:
The driver you recommended is programmable, from reading the directions it seems fairly straightforward, simply follow the directions.
For the application I am considering using the driver what would be the purpose of the spring?
My assumption, correct me if I’m wrong, I could get a block of aluminum heat sink, say 4”, mount my 2 or 3 led emitters with optics. I would want 1 or 2 floods and a spot, being that they are underwater and I want a decent throw for the spot I would want to use a reflector for the spot, but for the floods would I still use a reflector?
Where do the drivers go? are they mounter with the leds on the heat sinking? Or for this application should I have them with the batteries in a sealed compartment? Wouldn’t I have a significant voltage reduction if the drivers were close to the batteries and there was say 48” of wires from the battery/driver to the emitters?
Also you mentioned 2 cells would only get an hour of run time. how about using 4 18560’s or a different battery all together?
Sorry for the berrad of questions, I appreciate all your help so far!!
Welcome to the forum Chad.
Interestingly enough, my son is Chad B. Or was, lost him some time back…
Looks like you’re on the right track, the key thing will be making sure NO water gets to the cell/cells, so if you can arrange them in a watertight pack that may be kept above water then you’re in good shape. Direct drive from one of these cells to a single emitter is fine, they work all right that way. Using two or more, in parallel, it would be best to also use two or more cells in parallel for the run time.
There are TIR optics (Total Internal Reflection) that would give you the ability to use a wide angle or diffuse flood beam as well as a spot, you could mix and match those to get the beam profile that worked best for your application.
As you suspect, longer lead wires between the cells and emitters will keep the emitters from seeing a maximum current draw, so you should really have no issue as long as you’re maintaining the 4.2V with parallel cells and parallel emitters.
If you ran series emitters then you could also run a series cell configuration, but the problem there is that if one of the emitters fries or is killed somehow then you lose the whole string.
Hey DB, sorry to hear about your son, regardless of how long it has been.
Thank you for the intel, much appreciated!
So I think I may have a plan now, I will run either 2 or 3 XP-L hd’s in parallel. Most likely on a block of heat sink, unless I can fabricate something for them to mount to that will fit inside a PVC fitting. Either direction I can figure the platform out that’s the easy part for me.
I plan on ordering several emitters to experiment with, also incase I fry some during the learning curve!
Then I will run wire approximately 48” or wire, gauge to be determined, from a 2 or 3 pack of 18650 batteries the number depends on the amount of emitters used. Also in parallel (I am very familiar with running things in series and parallel, at least with 12v batteries for trolling motors and such)
I can waterproof the battery pack so moisture shouldn’t be an issue. I plan on using some bullet connectors and having a couple battery packs on standby because it seems like I will only get 1-2 hours runtime using this setup.
If yall see anything I am missing or room for improvement feel free to criticize all you want.
I’m starting to realize why yall get frustrated with flounder guys popping on here and asking questions, lol. These questions are probably elementary level to you guys, I really appreciate the help!
Just an idea, stick with an XM-footprint, eg, an XM-L2 in your choice of emitter (CT, tint, brightness), and with a nice block of copper, make a quad. Easier to drill holes in a square grid than to try to get an even triangle for a triple.
Get 20mm stars for more surface area and easier drilling, and get some TIR lenses that fit, like
then slap on some thick o-rings as spacers, and a piece of plexiglass to press them down onto the emitters (or use the front glass of your rig to do that). You want an air-gap between the lens and anything else, so you don’t screw up the beam pattern too much. Or you can try it without, see how the beam comes out.
With 4 instead of “2 or 3”, you’ll have more redundancy in case any of them fail, and you can either drive them all just as hard each for more total light, or don’t stress them as much and keep the same light.
Don’t forget, you’ll be shining from air (inside the head) into water, so the beam will change regardless, but the straighter it is coming out, the less change there’ll be.
You’re not too interested in “modes”, are you? In which case you’d probably be better off using simple and reliable 1-mode drivers, like
both 20mm drivers (same diameter as the 20mm stars). A 20mm bit will let you drill into the reverse side of the copper behind each star and wire them up in parallel. Solder the rim to the block (or solder a wire to each for the (-) connection), and tack-solder a wire to the center pad for the (+) connection.
The problem with PVC is that it’s thermally insulating. If you can scrounge a nice head from a flashlight, you can make it pretty waterproof, and the metal head in direct contact with water should keep it nice and cool. Don’t rely on o-rings, though, but use RTV in addition, and let it thoroughly outgas before sealing it up. Ie, try to make it a permanently-sealed unit that you never have to touch.
