Brighter lights with smaller LEDs?

[Deleted member 97529]

Are there any reflector based flashlights with a Cree XP-E driven at ~1.7A for maximum throw or an XP-G at ~2A for a throwy bright light? I searched for a long time and found that most lights only push these LEDs at a maximum of 1A. Is it difficult to drive them harder?

 

[higbvuyb]

Are there any reflector based flashlights with a Cree XP-E driven at ~1.7A for maximum throw or an XP-G at ~2A for a throwy bright light? I searched for a long time and found that most lights only push these LEDs at a maximum of 1A. Is it difficult to drive them harder?

Cree says the maximum drive current of an XP-E is 1 A and XP-G is 1.5 A. If you go higher, you might fry the LED. And then it won't be bright anymore.

 

[meeshu]

I don't know specifically of any lights having LEDs being driven at 1.7 A for XP-E LEDs and 2 A for XP-G LEDs.

According to Crees' specifications, XP-E LEDs maximum drive current is 1 A, and XP-G LEDs maximum drive current is 1.5 A.

Driving LEDs with currents greater than maximum will increase output (brightness), but will lead to (excessively) high LED and corresponding component temperatures, and reduced LED (and other components) life span. The greater the drive current, the less the life span. Lights will tend to fail early; the word will get around; nobody (or very few) will buy those lights anymore; manufacturer looses money.

Maybe because of this, some manufacturers do not over drive the LEDs. However, many manufacturers do over drive LEDs, but usually at moderate levels (~ +20%). Lumapower, for example, has at least one XP-E LED based light which is driven at 1.2 A.

 

[Deleted member 97529]

Cree says the maximum drive current of an XP-E is 1 A and XP-G is 1.5 A. If you go higher, you might fry the LED. And then it won't be bright anymore.

It's the heat that fries the LED, so it should be fine with good heatsinking. :thinking: pct.cree.com states an XP-E can produce 330.8 lumens at 1.7A, and an XP-G can produce 538.9 lumens at 2A.

Saabluster sells the DEFT HO with an XR-E driven at 1.7A.

 

[kengps]

The light Lumapower drives at 1.2A is an XR-E. Not sure what they sell anymore with an XP-E. It's all a matter of heat. Saabluster runs the DEFT at 1.7A, but he solders the LED directly to a copper heat sink. I drive my XR-E R2's at 1.4A with 20mm stars thermal epoxied to the heat sink. I'm sure I'd fry it pushing 1.7A without the LED directly soldered to the heat-sink.

 

[higbvuyb]

It's the heat that fries the LED, so it should be fine with good heatsinking. :thinking: pct.cree.com states an XP-E can produce 330.8 lumens at 1.7A, and an XP-G can produce 538.9 lumens at 2A.

Saabluster sells the DEFT HO with an XR-E driven at 1.7A.

Presumably even with an arbitrarily good heatsink the tiny LED itself acts as a bottleneck for heat transfer and so you still get heat buildup and reduced lifespan.