3.7 vs. 7.4 LED Question

[t-roys]

Got a quick question for all the masters. Are the CREE LED's rated at 3.7 to 7.4 volts? My question stems from my son putting two CR123's in my hunting light and it burning up instantly. It normally uses an 18650 at 3.7 and he though well same size what the heck! Now I have a dead light. The light is a copy of an Ultrafire C8 with a red LED in it. Thanks! :twothumbs