Help me choose some components

Thanks, looks like Luminus is most efficient for the same amount of power. Very nice led.

Yes but Cri is low and cold white. Also, you can see how current increase with the Voltage. Pay attention to set right V out with small modules like lm2596 to avoid burn chip.
XL4015 can hold more power and the CV version came with heatsink.

Yes, I’ll test everything in my workshop before the final installation. Once I set the voltage, I’ll glue the potentiometer to avoid any movement during road use.

These module work with high Frequency PWM.

There are also “12V speed controller” on Ali that can be use for dim strip Leds

Some people made custom linear regulators by use crude Mosfet like IRFZ44N or transistor D882, TIP41…
like this guy, but think heat will up.

If you want, post your projects and good luck :wink:

Since you are not in usa, it is hard for me to tell you where to get them, but they are pretty common, carclo 10507 are spot lenses, oval 10510. us based led supply, and mtn electronics have those in stock,

I would wire them in series, since you have 12-14v system, and those are 3v leds, you have just enough overhead voltage. if you wire them in parallel, you'll need 3 times the current but only 3v. so in one case you need 1.5-2A driver, in other 4.5-6A. You do not want to drive leds at max current, i would lower the current and double the amount of leds/drivers, for reliability. and they run cooler, but it is really up to you, either way will work, depends what driver you can get. xpl can handle more max power than xpg3, 3 vs 2A but i'd run them at around 2 and 1.5A.

You can use quads, instead of triples, those i'd wire 2s2p, or all parralel, for a buck driver, in theory you can use a linear driver for quad in series, but i have not seen a reliable linear that will handle 12-14v of dirty power, not to mention you'd need to heatsink that driver, however i can't find any oval lenses for quads, i do not think they are even available, but i may be wrong.

As far as tint, i'd go for 4000-5000k for spot, and 2700-3000k for fogs,

Driver boards that i used common lm2596 boards, i used them in cars to power various devices, dashcams, wireless chargers... only 1 out of about a dozen failed, but i doubt it is due to dirty input, most likely deflective unit, since they are 2-5 dollar boards, it is expected.

Very thorough answer alpg88, Thanks.

Now I have all pieces of my puzzle :-).

Boards for led in 3P can be converted in 3S by cut traces and reverse the 2nd Led.

For Quad cfg you can consider also separate channels 2S + 2S for an adjustable CCT light.
In that case you need 2 modules and knobs

Try check at Emisar or Convoy for Quad mcpcb but maybe need to be mod for 2S 2S channels cfg

Not sure if a buck converter to bring 12 Volts down to 12 Volts is a good idea…
I mean what if your battery runs low and you drop engine revs?
You may be left to work with 10.5 Volts or something, and then you would need a boost for your 12 Volts LEDs.
Seems to me you would be better off with 6 Volts LEDs.

So it is just silly nonsense that people use Constant Current drivers for LEDs?

You can use both. But constant voltage driver should be tuned for dedicated led to output desirable current. More voltage- more current.

Yes, P = U • I
But an LED doesn’t have a fixed resistance, it also depends on its temperature, it is afteral a diode and behaves like a diode.
With a constant Voltage thermal runaway can occur too.
Especially in a set up on a vehicle, temperatures can vary significantly.

Have a read here:

Hi Jerommel,
Maybe for this specific application would be better to use cc cv buck converter and limit the max current?

6v led, buck cc cv converter to lower the voltage from 12v to 6v and limit the current using second potentiometer in case of thermal runaway.

When Voltage is fixed on first pot. then adjust current on the second, at certain point current didn’t increase more? (Since V. was already set)

You don’t need CV, just CC.
I looked on AliExpress for buck drivers but i can’t find anything (yet) suitable, provided that you want to build lights that individually run on 12 Volts from your battery.

This module works both ways, CC or CV. You can limit the current or you can limit the voltage. So if I limit the current at, let’s say, 1,5 A and set voltage at 7-8 V (for a 6V led) it always stays in CC mode.{"sku_id"%3A"66542222514"}&pdp_npi=2%40dis!EUR!2.51!2.01!!!!!%40211bf48d16712930936134462d075e!66542222514!sea&curPageLogUid=4nmNitd8fQ6L

There are many options…

or buck/boost

It’s a nightmare to adjust those things properly, at least to me it was.
Those (with the chunky 5 legged regulator) are usually not that afficient and not up to the specifications either.
I had one burn itself at 1.5 Amperes…

I did find these to be interesting:
Dedicated LED buck drivers with a wide range of input Voltage.
Not the output Current you’re looking for perhaps, the strongest option is only 900mA.
But you can put them in parallel so it would be 2800mA if you use all 3.
That’s roughly 20 Watts at 6 Volts, that should work very well on a XHP50.3 (for example).

The specs are always about half of those declared for run continuously. These modules won’t be super efficient, but for a 12V battery that stays charged with the alternator shouldn’t be a problem

I have two cc cv modules at my workshop and I’ll test them thoroughly before I make a final decision. What’s the worst that can happen, maybe they will burn out.

These small constant current modules that you propose are very interesting but there’s no way I can stuff three of them inside my light. Maybe I could mount them somewhere outside but that complicates things because there is no room.

Don’t know how this works but they sell it. This module probably goes into cheap fog lights that they sell throughout aliexpress.{"sku_id"%3A"12000018435669197"}&pdp_npi=2%40dis!EUR!10.81!10.81!!!!!%40211be3d216713109746638647d0751!12000018435669197!sea&curPageLogUid=yDr5WzM22uam

You’re right, efficiency is not my main concern. Alternator will have enough power and more.

when you use cv cc board, as a driver set your current, voltage doesn't really matter what you set to, as long as you are not starving the led, led wont get more volts that it uses at than set current. The same principle as those tiny keychain light that use 2 cr cells that total 6v and 5mm leds that need 3.6v, leds work just fine, cuz those coin cells are unable to provide much current, so extra voltage is harmless, but hook such led to a 4AA cells it will burn immediately.