High Power LEDs connected to car battery

I'm looking into some custom vehicle lighting and need some help with understanding high powered LEDs.

Can I use these four LEDs connected in series ( http://www.luxeonstar.com/PC-Amber-591nm-23mm-Quad-LED-528-lm-p/sr-08-l0000.htm ) and connect them directly to a standard car battery without any needed components?

No, high power led must be driven from constant current driver modules, not a fixed voltage.


Can you explain that a little more?

What components would I need to make it work?

Or at the very least there must be current-limiting resistors - unfortunately those 4 in series would work best from about 15V with 3.9 ohm 2W series resistor - there's not enough headroom from a car battery (which varies from 11.5 to 14V). Remember the forward voltage of LEDs changes a lot with manufacturing variation, die temperature and current.

There are chips expressly designed for running LEDs in series, they are voltage boost converters with constant-current output drive - look for some of these.

From your datasheet you posted there is a link to driver modules they supply/recommend for use with their high power leds. You have to know the operating current for the specific leds you pick from their offerings:



Ok, so say I use this driver ( http://www.luxeonstar.com/1400mA-Externally-Dimmable-BuckBlock-Driver-p/a009-d-v-1400.htm ) With the two of the LED boards I mentioned above I mentioned above wired in parallel. Would it work?

You cannot drive two LED boards in parallel with a single constant current driver. The driver has no way of splitting the 1400ma current into two equal 700ma chunks for each of the boards.