LED AMP and Volts question

I wanted to replace a led in a police security light I own. when I took it apart I found it was not like the others i own which an emitter swap would be easy. so I decided to get a new star and place it in instead of just a led. it is a 16mm star and i saw a star with a built in emitter which produces 1k lumens an XML. How am i to know if i am able to run this led on 2 AA batteries with a driver that originally came with the light? i just need to know the relationship between Voltage, amps, driver, and the led in which I'm trying to run.


LINK: http://www.cree.com/led-components-...e-directional/xlamp-xml2#sthash.RuAFDUBe.dpuf

Do you have a multimeter? That's the only way to find out what voltage/ amperage your driver puts out.

Yes, a Cree XML2 can put out 1,000 lumens, when driven at or slightly above maximum amperage (3amps). A couple AA alkaline's are not going to be able to deliver that kind of amperage.

What brand/ model of police light do you have?

It was a 300lm 2xAA light. Thats all i know. I dont have a multimeter but i can pick one up for a few dollars. I just moved into my new mortgage so i dont have many tools currently.
It sounds like an XML2 would be a bad choice then given that it wont reach full ampridge with 2x AA and the battery life will be low. but how am i to know if i can use a driver with a specific led and battery combination? May i please have an example.

No matter the driver/LED combo, if the batteries aren't up to the task, it will be underpowered. You can direct drive an XML2 with 2xAA, no driver needed as long as there's moderate heatsinking.
If you're really looking to get some "oomph" out of that light, I suggest switching to a higher power battery such as lithium ion rechargeable. Easily pass the 1kLm mark with the proper driver and cooling.
However, underdriving a LED isn't always a bad thing, even direct driven that light will exceed 300lm with an xml2.