How fast would 17 LEDs drain 3 AAA batterys, if the LEDs were 18 candela each?

Question

I am using LEDs from this site : http://www.superbrightleds.com/leds.htm
They are product number RL5-W18-15
Tech specs are :
http://www.superbrightleds.com/specs/w18015_specs.htm

I want to replace the 17 weak LEDs in my cheap flashlight, I have no idea how powerfull they are, with 17 of these 18 candela LEDs. The light operates on 3 AAA batterys that I believe are in a series. I think all LEDs run on 1.5 volts. My question is how long would good quality batteries last?
Thanks in Advance.

I'll check that site.
Also there are no resistors, or anything else for that matter on the PCB that the resistors are soldered to.

Basically what I want... is an LED flashlight that is so bright that it will actually stun and temp blind an intruder in my home at night.

Answer 1

It's not quite as simple as replacing the LEDs. Most of them have a current limiting resistor in series. Changing to brighter LEDs would possibly mean changing the resistor too.

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