~10W 12V boost driver?

Hey there,
I am looking for a driver which would supply 0.5A - 1A at approximately 12V (4 LEDs in series), from single Li-Ion (3.7V).
Form-factor does not needs to be flashlight-oriented, I’m fine with classic rectangular PCB’s as well.
I have looked at TaskLED drivers, but those need at least 4V input, and are expensive… since this is Budget light forum, maybe you guys know some options?

I am also trying to find such a driver too! No luck as of now, except for the PCB board in some 18650 power banks that output 12V.

I’ve seen something like that recently, but can’t remember where…
I think the description said something like 5x XP-E in series or something i.e. not high current.
Could have been FT.

Why not a linear driver with the emitters in parallel? .5-1A is very little load, a basic 2-3 chip 105c could do that all day and you’d have better run time from a single cell than you would with a driver boosting it up to 12v.

Because the emitters are already configured in series and it’s very difficult, if not impossible, to change that configuration.
It’s a 3 meter long strip with 180 LEDs on it, 60 parallel arrays of 3 LEDs + 1 ohm resistor. Since every LED is rated at 10mA typical and 25mA peak, I’m looking at ~600 mA driver, but since finding that exact current is probably next to impossible, anything within the range would work for me.

drivers like that are not easy to come by, (under 5v input.) ive seen few such things in my life and all were custom made. prbly easiest way would be to use step up voltage regulator, and than linear (not amc based driver) driver or buck driver.

with boost driver, you would have at least 5-6Amps input