lithiums AA's in fenix & SL propolymer ?

[Saiga]

i have a streamlight 4AA propolymer on the way, and will probably leave it in the console of my car. i also have a fenix that in a back pack i have with me at work. i'm wondering if i can, or should, use lithium batteries in these lights. thanks......

 

[MarNav1]

Expensive but good choice. Last a long time and few leakage problems. Also good in cold weather.

 

[Marduke]

lithium primaries (like e2 energizers) yes, 14500 li-ion, a big NO