powering a 6 Watt LED

EDIT: Okay so I'm changing the LED I'm using. Now I'm using a 6 Watt LED. There's more info on the link, its a EcoSmart MR16 6-Watt (20W Equivalent) LED Flood Light Bulb (16 WW FL). I know I'm going to have to redo my circuit a bit. But can you help me now? Thanks.

I'm trying to power a 6 Watt LED using 3 NiCad batteries (3.6 volts). But the LED spec sheet says its a 12V LED. Should I use a booster? I don't really have much experience in electronics.

EDIT: (I deleted some of the old stuff)

I also designed a circuit:

Now the problem seems to be that there's not enough voltage from the battery or enough current in the circuit to power the battery for a long period of time. I'm powering the circuit through this generator. The generator only provides 8.2 - 9 V and 17 mA. I'm not really experienced in this so can someone help me figure out if a better generator (such as this one) will help me? - btw when I tested how much the output from the motor was, it came to a max of 16V when I was cranking it really quickly.

Another problem with using 3 AA NiCad Batteries seems to be that they won't power the LED for a long enough period of time. Will using capacitors eradicate this problem? And if so which capacitors?

To clarify: The generator is hand cranked and through some testing its max output is about 16 V (cranking it really fast). This charges up the batteries and the batteries then power the 6W LED. I know I need diodes, resistors and capacitors in the circuit, but I've never really worked with this before so any help is much appreciated.