Now that I've played a few games one thing is very apparent - the Tower goes through batteries like a kid with a bag of Halloween candy. A brand new set of batteries will begin to get "Low Battery" warnings within a half hour of installation. In 1-2 hours the Tower will begin to "Jam" during rotations. Removing the batteries and checking them with a battery tester will still read in the Good range, although towards the lower end of that range. Apparently the Tower can tolerate very little drop in the 4.5V a fresh set provides. Up to this point all of the batteries I've used have been regular Duracell copper tops because that's what I had on hand. I just purchased some Energizer Ultra Lithium batteries to try so I'll see how those work out. I'd be interested on hearing from others on their experiences with battery life and what brand seems to have the longest durability. A high power battery pack like the RC planes and cars use would be welcome upgrade. As I'm planning to host two sessions of Return To Dark Tower at Owlcon next month I don't want to be caught short. It would be disappointing to the players as well as bad PR for the game if it doesn't hold up without having to repeatedly put fresh batteries in the Tower.