2008 Prius Starting and Computer Reset Issue

I have a 2008 Prius with about 55,000 miles. Today after work I got in and went through the normal starting procedure, but nothing happened. I stepped out of the car, took a quick lap around the car to check for anything noticeable, and locked and unlocked the car with the key-fob. I sat back down and it started up just like usual except that the trip odometers and clock had all been reset, and my radio presets were gone. I recently replaced both the key-fob battery as well as the 12V battery within the last couple of months. Any ideas what might have caused this?

 

Just checked the voltage and the diag screen is showing 11v, so it seems like the battery is defective. A $150 battery should last more than 7 months. I hope that obtaining a warranty replacement is not a pain in the nice person.

 

I probably will do that while waiting to see about a replacement, but a 7 month old battery that goes dead for no reason is defective and I would rather not risk getting stranded someplace with a dead battery if it fails again.