I actually made it for a friend who is doing field research on the Bay of Fundy studying birds and capturing them at night. Part of her Doctorate program and funded through grants. So it is set up to plug into the boat's battery. I hooked it up to a 28V Lithium Ion battery pack from a Milwaukie hand tool and it worked great. I have three 1000ma buck pucks, one for each triple, and they are mounted to heat sinks which are thermally glued to the aluminum case. It needs air flow to stay cool. It is brighter than the 5,000,000 candle power torch on the boat. It has 2 X 16 degree spots and one 16 X 38 diffuser.
The hands free aspect was very important for her. I rode with it once! Almost too bright!
But 3 amps at 13.2 volts keeps it viable for a bike. With a 28 V 4800mha battery you would get 3 hours or so...I think.
Those are going to burn up real quick without any heatsinking! Looks like you are just relying on the MCPCB's?
They are mounted to heat sinks individually and thermally glued to the aluminum case. It needs air flow to stay cool. It gets hot if there is no air flow. I rode with it for an hour and it worked great. I kept it on at my shop with a fan on low for 2 hours and it kept working without a problem.
Here are some pictures of the components and heat sinks before assembly. The case is an old 350 watt inverter box which is designed to be a heat sink on its own. I cut it into two halves for two lights. Haven't done the second one yet. Waiting for the field report from the Bay of Fundy.