voltage question...

TopGunWgHs · Jan 6, 2008

CREE Q5 from different sites, some say 4.5-9.0v and some say 3.8-6.0v now does this mean when your batt. source reaches 4.5 the led stops working, or starts to really cut down on brightness, or 3.8v such as the other one says, so if i hav to 3v SF123a's in a 6pled, which drop in would i want more? the 4.5-9. or the 3.8-6. if i wanted the longest brightest run time? thanks for bearing with me you guys this is probably the 3rd cree q5 thread ive made, just want to make sure i get the right one!

Gunner12 · Jan 6, 2008

The LED voltage is probably between 3.5-3.7v depending on drive current, what you are saying in the input voltage for driver. A Cree XR-E Q5 only tells you about the LED it self, not the whole drop-in because 6v directly will probably fry the LED(hence the need for a driver).

You would have to know the driver specs of the driver used in the drop-in to know which will give you the longer runtime, more output or which one will shut down after a curtain voltage.

:welcome:

Steve L · Jan 7, 2008

TopGunWgHs said:
CREE Q5 from different sites, some say 4.5-9.0v and some say 3.8-6.0v now does this mean when your batt. source reaches 4.5 the led stops working, or starts to really cut down on brightness, or 3.8v such as the other one says, so if i hav to 3v SF123a's in a 6pled, which drop in would i want more? the 4.5-9. or the 3.8-6. if i wanted the longest brightest run time? thanks for bearing with me you guys this is probably the 3rd cree q5 thread ive made, just want to make sure i get the right one!

The drop-ins use different drivers. What the numbers mean is that the pills will be regulated(constant output) in the voltage range(manufacturers claim). When the batteries drop below the recommended input voltage the light will fall out of regulation and get dimmer. To answer your question: Get the 3.8v-6.0v to run with two CR123's. If you wanted to run 2 RCR123's(8.4v fully charged) or 3 CR123's you would want the 4.5-9v module.

voltage question...

TopGunWgHs

Newly Enlightened

Gunner12

Flashaholic

Steve L

Flashlight Enthusiast

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