Wiring a 5 watt LED??

[wht420aeclipse]

Ok this is not car related but i'm working on a little project. What I want to do is buy a 5 or 6 d cell maglite and use my 5 watt led in it.

Specs on the LED:

Continuous Forward Current 800 mA
Forward Voltage 7 V

Peak Forward Current 2000 mA
Power Dissapation 5 mW
Reverse Current 30µA
Reverse Voltage 10V
Wattage Consumption 5W


Peak Forward Current (1/10 Duty Cycle,0.1ms Pulse Width) IF(peak) 2000 mA
Continuous Forward Current IF 800 mA
LED junction temperature Tj 120 °C
Reverse Voltage VR 10 V
Operating temperature range Topr -35°C ~ +50°C
Storage Temperature Range Tstg -35°C ~ +100°C
Flux Characteristics (Tj = 25°C)
Color Lumen CCT Range CRI
Cool White 350 6000-7000K 70
Warm White 220 3000-3500K 60
PARAMETER Test Condition Min Typ Max UNIT
Viewing Angle 2θ1/2 IF=750mA 120 125 130 degrees
Forward Voltage VF IF=750mA 6.5 7.0 7.5 V
Reverse Current IR VR=5V 30 uA

Can I just use a 5 D cell Maglite and directly connect the led or do I still need a resistor in line? D cell I'm using has a mAh of 12000

Or should I go with a 6 D cell mag equaling 9V and slap a 2.2ohm 1 watt resistor in line?