I took my 2016 Prius 4 into my local dealership today to have the Intelligence Clearance Sonar Service Campaign and the Engine Wire Harness Recall taken care of. I had a coupon so I also opted for a reasonable priced oil change and tire rotation. The importance of this visit was that my car is two days short of 3 years old and 500 miles short of 36,000 miles so that the new car warranty is still in force. The dealership called me and said that part of the recall work required that the 12 volt battery to be checked and that mine had failed their test. (A surprise to me as I have had no indication of battery issues) Because the car had a slim margin of warranty remaining, they are changing out the battery at no charge.
I picked up the car with the new battery. Was just as promised - it was free under 3 year 36,000 mile warranty. I want to add for information sake that all of my settings, radio stations, trip odometers, and mpg history on the eco screen were all intact. No loss of any data with the installation of the new battery.