A few week ago at WorldFest, Steven with LEGO handed me three packages of Energizer Lithium batteries (2 per package)... he said "try these out."
I put them into my brick that I'm using for testing robots in a new book (where I'm constantly stopping, starting, stopping, etc.) and decided to see for myself. Having used a mixture of alkaline and rechargeables in the past, I have to say these things are unreal... I'm still using them after about 2 weeks of daily use and they're still showing 8.X on the battery meter. I've seen no change in performance either.
They're a little higher priced than the batteries I'm used to using, but for testing purposes, I'm really leaning towards switching over to these during those critical testing periods. It made me think of FLL teams who are also constantly testing and need reliable batteries.
I'm interested to hear from our readers on their battery experiences. For those who don't use the NXT rechargeable, what kinds of times are you finding on the batteries you use? What do you use?