lithium mate , wouldnt go back to lead acid , i know the price is a turn off but there worth it in my opinion , i get a good night and more from a 14ah using 50watt bulb , small and light enough to put in your jacket pocket too .another plus point for me is the battery state indicator . back when i used lead acid i seemed to do half the nite with a full power beam and the rest of it with a gradually fading beam , not really knowing when it would give up . i believe a lithium will stay the same and then just stop working when its exhausted , atb with whatever you decide to get , phil