headlamp flashing problem.

so i found a very old headlamp. it still had a halogen bulp in it. so i figured out i would mod it with a xp-g2 R5 A1 and TIR optics.
it ran of a 4.5v (3LR12 size) battery. i decided to throw that away and use 3 li-ion batteries in parrallel to provide higher runtimes.

i also installed a 1A Li-ion charger from DX to charge them over USB
(http://dx.com/p/1a-lithium-battery-charging-module-blue-205188)

to run the xp-g2 i stacked 3 AMC7135s to provide the led around 1Amp.

but now my problem. when i turn the light on it turns on for around 2-3 seconds and than starts flashing.

what could cause this flashing?
and what could i do to stop it?

thanks!

Hard to say… you could have a bad solder joint somewhere, or it could be a thermal problem. What are you using for a pill/heatsink for the led/driver?

no i dont have a heast sink for the driver i just stacked 3 amc7135s

im going to try a 105c @ 2Amp now with a xml2 on copper. i burned my led trying to solve the problem

the heatsink for te led is 5 AL plates solders together.