Originally Posted by
littlewaywelt
I do. One upside to alkaline is that you know the batteries are getting weak. With lithium, they will run until they are dead and then die all of a sudden. I like knowing that I need to replace the batteries before they are completely dead while I'm on a ride.
I was going to add that too, but didn't because I imagine most carry spare batteries / battery. I consider my keychain light, an ARC-P, to be adequate backup, but I don't do serious night riding, mainly a 1.7 or so mile partial commute with very light traffic.