so when you added a resistance in serise (the current meter with small leads) it ran fine. when you ran it without a resistance it went blue (the new leads and getting 10+amps).
I suppose you could try it with the batteries half dead and see if the current goes real high (useing the thick leads). if no blue/over current then yes, the batteries are overdriving it and you need a resistance in serise or a driver or an LED that can handel more power.
on teh idea of putting an sst90 in:
it shoudl be able to handle nearly double the current at the same voltage. with your batteries hot off the charger it may still be fed too much power, it is hard to say without testing it.
so the simple answer when and LED does the angry blue thign is that heat is not being carried away from it as fast as it is being produced and that heat is building up WAY too fast. if you glue an LED with pcb to a block of wood i'd expect it to go blue on much less than 1 amp. if you do somethign super awesome to heat sink it you can put more current than it is rated for. (some one here got 5+ amps through an XP-g, normaly rated at 1.5 amps)
sounds like you have good heatsinking (so you should be able to run around max current for a while) but that you are runnig 2 or 3 times as much current as the LED is rated for. so when you ask if you need a resistance or a better thermal path the answer is 'either'. you coudl put the LED on a HUGE copper block with heat pipes and fines and fans and liquid nitrogen and maybe some magic or you can put a resistance in serise to reduce the current/power.
TL;DR: see post #4.
I suppose you could try it with the batteries half dead and see if the current goes real high (useing the thick leads). if no blue/over current then yes, the batteries are overdriving it and you need a resistance in serise or a driver or an LED that can handel more power.
on teh idea of putting an sst90 in:
it shoudl be able to handle nearly double the current at the same voltage. with your batteries hot off the charger it may still be fed too much power, it is hard to say without testing it.
so the simple answer when and LED does the angry blue thign is that heat is not being carried away from it as fast as it is being produced and that heat is building up WAY too fast. if you glue an LED with pcb to a block of wood i'd expect it to go blue on much less than 1 amp. if you do somethign super awesome to heat sink it you can put more current than it is rated for. (some one here got 5+ amps through an XP-g, normaly rated at 1.5 amps)
sounds like you have good heatsinking (so you should be able to run around max current for a while) but that you are runnig 2 or 3 times as much current as the LED is rated for. so when you ask if you need a resistance or a better thermal path the answer is 'either'. you coudl put the LED on a HUGE copper block with heat pipes and fines and fans and liquid nitrogen and maybe some magic or you can put a resistance in serise to reduce the current/power.
TL;DR: see post #4.
