Do you mean not to put the batteries in wrong direction? How would I know which way to put?Heat sink and make sure you NEVER reverse polarity on the driver.
a fan can be used to briefly test it at full power if you don't have a heatsink ATM.no more than 2 or 3 seconds though.
if you use a lower voltage source the driver should run it at lower power if it needs (6-9v or whatever it said the driver needs)
you can run it from one fully charged 18650 or 4 nimhs to use it at a lower power and make less heat that way. whatever you do MAKE sure the polarity of the power source is right otherwise you'll blow the driver. I had my share of accidents with reverseing the wires. if it happens the dioide will most likely be very dim even at the upper voltage limit. Don't mess with it or you could loose the dioide too. You'll need a new driver. Oh and make sure you got googles ready if you're gonna run it at full power.
Forgot to say but it's a G2 lens.Did you get the 3 element or the G-2 lens? Power it with two 3.7V Li-Ion batteries. Be aware that thing can really burn stuff. Mine is driven at 1.5A and with a 3 element still meters at 1.5W. If that's driven at the usual 1.8A it may do more than 2W.