I’m the second owner of a 2008 Toyota Prius (Package II) with 23k miles. I have a question about the different batteries. I understand that there are two 12 Volt batteries (one in the rear and one in the front under the hood) and there is one 201.6 Volt Hybrid battery (also in the back). If I ever would need to jump-start the car it is explained that that needs to be done using the front 12 Volt battery (p. 451-452 of the 2008 Owner’s Manual). Question: What is the back 12 Volt battery for? Is it connected in the same circuit as the front 12 Volt battery?
There is only one 12v battery and it sets in the back. There are "jump" terminals in the front just for convenience.
Jump your car (don't jump others) from the front two terminals. Under the hood, right side remove the black cover. Red terminal + and ground is just above that (a post). see your Owner's Manual for further instructions http://answers.yahoo.com/question/index?qid=20080902094104AAMGVuq Toyota Prius Battery - Information on the history, specifications, modifications and future development of the hybrid's battery pack.