That's always a tough question. Like cedfire said, it depends on the light so it's best to ask the manufacturer. From the infosheet I scanned on Streamlight's website for the Survivor, it doesn't prohibit lithiums. However, over at Flashlightreviews.com, a mention is made that Streamlight does specifically warn against using lithiums in this light. I don't know where that info comes from, but without other evidence to the contrary, I would be inclined to heed that warning with this light.