I’m ordering led’s for a lantern that I’m making from scratch. I just can’t decide how many led’s I should buy yet or what tints.
I’m using spare parts that I have laying around. A 3x18650 battery box, 9amp driver, an extra tail switch, some copper pipe and a bunch of old pennies might see some use along with a half gallon mason jar, car door handle and Christmas spray. Hmm I’ve got some gorilla glue and JB weld that needs to get used up too. Aluminium cans melt real good over a camp fire. I’m sure there are a few things missing like the kitchen sink but you get the gist of it.
I’m thinking maybe 20 3 watt led’s 6 white and 6 warm white then maybe a red one or two tossed in. 40 cents each for LED’s on GadgetsDealer. It should make for an interesting $10 hillbilly camping light.
What I wonder is how many 3 watt led’s I should run with a 9amp driver. Anybody know?
A 3W emitter will be rated around 800 to 1000mA. You should have at least 15 in there.
The 30 number is good because the emitters are more efficient when under driven. In this case, 1W emitters would work as well.
You will be lucky to get 100 lm each. You can find good quality 1W and 3W emitters, but it is hit or miss. I got some OK ones from DX a while back.
You will have close to 30W of heat to deal with so the heat sink should be a good size.
They have 1W ones too. Any idea which would be better? The 1w ones are only 24 cents each. I guess I could wire three rows of ten or even 4 rows of 7 or 8.
I think it would be better to just buy, say 4 XM-L T6 3C and one T4 3B from fasttech.
Im guessing output would be better, tint would most likely be much better, beam would be more useful (it would throw further, while still having lots of flood) and not just be 100% flood. Would be easier to make/wire. 5 LEDs vs 30… And if you wanted reflectors on all those leds…. :zipper_mouth_face:
BUT, that is what I would do.
From where I am sitting, I would rather see a build thread where you used 20-30 of those LEDs and made a super unique light…
The LED you linked too remind me of the LED spotlights I have on the roof right above me now (very temporary!).
One spot use 3*3 of those warm (dreadful) LEDs. I received 5 of them as a gift so thought I should give them a chance the other day. A total of 45 emitters. And all of them use TIR optics with around 50 degree angle. Supposedly they are 3x3W.
They suck! They have a strange artificial light… I believe there is some pink-ish color in there, and CRI is not great.
One bare XML T3 7B in each spot would look much nicer than what is already in there.
Im debating to either throw them away or rebuild with Nichia 219 3000k (92 CRI). But it would be a lot of work and $$. They are best suited for my attic… But I would rather use a flashlight there with nicer tint then those spots lights…
If I would have them in the spare parts bin it would mostly be to have emergency back-up spots or to use the TIR reflectors/holders. Not the LEDs. Unless I decided to do a project like yours…
Dont let me put you off making a super unique budget light… Just sharing my thoughts and experience… I do believe you are playing a lottery with very small chances of great results… So just a friendly heads up…
You will have to consider if the driver will output enough boosted voltage to overcome the vf of the series array of leds.
I have no idea on how much voltage the driver will output. If you have 8 leds in series with a vf of 2.7v at 1 amp. Then the driver would at least have to put out 21.6v plus a little overhead to drive the leds at that current. You would need 9 different parallel arrays of 8 leds in series to divide the current between them wired in parallel. For efficiency it might be better to keep the battery voltage and led vf array about the same. Battery voltage at 3 x 4.2v =12.6v. Maybe 5 to 6 leds in series for voltage and 9 parallel arrays for the current. As the batteries drain the driver would boost the voltage and probably become less and less efficient as the voltage spread becomes wider. I have not tested the driver because I really don’t know which one it is, but most drivers work this way unless they are of high quality. The numbers I gave above are just a guess, you may have to look up the vf of the leds to get the right amount of series leds. But then again it could be a buck driver.
How was it wired up in the Uniquefire.
I think I found the light, is this it? http://www.lightmalls.com/best-quality-uniquefire-6t6-6-cree-xm-l-t6-7000-lumen-5-modes-led-flashlight-3-18650-3-26650
The true output is probably more like 7 amps. They (china) never tell the actual output its a manufacture rating max.
In the uniquefire the led’s are all in a row just wired from one to the next. I also doubt that it’s 9amps but it is very bright. I’m replacing it with a driver that is supposed to drive 7 leds at 2.5 to 2.8 each. It is the one from lightmalls. (I paid $45 for it) I’m going to review it with a before and after.
I was going to pull the 6 led’s out and use them for the lantern then replace them with new XM-L2’s but they are cemented down so hard I don’t know how to get them off of there.
Does anyone know how to get the cement off of the ones in there? If so I might just do that instead, but the 30 leds sounds like fun, too.
If there all wired in series it has to be a boost driver. So if you stick with 5 to 6 in series it should be most efficient. If they where all wired in the uniquefire in series then the driver was probably around 3 amps output. You should only need 3 to 4 arrays depending on how much current you want to use.
As for getting the leds out, I have a very small screw driver that I use to pry under the led. Sometimes it takes quite a bit of force to remove them. You may have to use a small hammer to drive the screw driver under them. I have not found a easy way to do it, if they have been really glued good.
