Most Efficient LED for 400 lumen output?

Hello all,

I'm new at this, and I'm trying to figure out what LED requires the least current to get about 400 lumens. High-CRI and a temperature around 3000k are important. A maximum output of at least 1000 lumens at 3A is also desirable. I can drive at either 3v or 6v (two lithium cells in series or parallel). I'll be using the TaskLED dualFlex driver

The new XHP35 and XP-L look like strong candidates, and the XM-L2 is popular as well. I'm having a hard time making sense of the cree data sheets.

Any thoughts?

Thanks,
Phillip

Hi Philip, and welcome to the forum!

In general, the lumens/amp goes up as the current goes down. So in general you want the biggest die you can find, and underdrive it a lot. It's possible to overdo this, as eventually the color shift would get unbearable. I would suggest you look at the XHP50 or XHP70. If you are really fussy about the CRI, the '70 might be overdoing it a bit, as you'd be down around 20% of rated current.

Thanks, I'll give the XHP-70 a shot. I imagine the CRI will be fine. If not, I'll make another and you'll hear from me again.