Simply visit a battery manufacturer's website and look at their datasheets.team_nightstalker said:ok here is my main question of concern. at a run time of 8 hours.... how long should the batterys keep up to this LED?
www.energizer.com shows that AAA alkaline cells can power an LED at an average of 25mA for about 48 hours. A 9V alkaline battery can power an LED at an average of 25mA for about 24 hours. The voltage continues to drop so the LED dims.
Ni-MH rechargable cells are also shown.