Hi, I'm fairly certain that these are the Titanium type Batteries which will definitely last much longer. I put these in smoke detectors and anything else where I wouldn't ordinarily use rechargeable batteries. Amanda Lee Alexandria, VA USA ----- Original Message ----- From: "Mike Arrigo" <n0oxy@xxxxxxxxxxx> To: <bookport@xxxxxxxxxxxxx> Cc: <bookcourier@xxxxxxxxxxxxx> Sent: Monday, December 06, 2004 8:17 PM Subject: [bookcourier] lithium batteries Hi all. I'm actually posting this on the book port and the bookcourier lists, since I own both of them, and it applies to both. If you use your unit a lot as I do, you may want to give the energizer lithium aa batteries a try. I bought a pack off of ebay, I think they're officially called, e2 photo batteries. In any case, installed them about a week and a half ago, and I use my unit every day. The level is still at 100 percent for both units. They cost a bit more, but it looks like they last much longer. According to the specs, they last 5 times longer then regular aa batteries, and they're also lighter.