So the old iBook battery was down to about an hour per charge, and I bought a new battery from Newer Technologies (advertised as 7 percent longer battery life). Newer offers a $19 rebate if you send in the old battery. Now, I've bought new batteries before, and I've never, EVER used the old battery as a backup. It's just too much of a pain to keep it charged -- you have to constantly be swapping out batteries, and whenever you do that, the date and time get messed up, which messes up iCal, yadda yadda. BUT, if my new battery failed it wouldn't be such a terrible thing to have the old battery around -- not as a day-to-day backup, but as a worst-case-scenario backup. BUT part of the reason I justified buying the Newer battery is the rebate program. So, what does the MR community think? Should I send in the old battery, or keep it around, "just in case"?