This may seem like a silly question but is the 12 volt battery that is in the 2007 Prius a "special battery" or is it just a regular car battery? Is this something pretty easy to replace? My 2007 Prius has been sitting for an extended amount of time and it is dead. No lights, no nothing. We tried to jump it (watching you tube and reading the manual) But it did not do anything.
it is both 'special' and 'regular'. it is special in that it is small, advanced glass mat technology, and has a vent tube that directs gases outside the car. other than that, it is just a plain old 12v car battery it is a bit more cumbersome than engine bay 12 volts, being under the right rear floor of the hatch. there are plenty of youtube video's, and it is under an hour ordeal for first timers. you can get oem from toyota, or aftermarket from auto parts stores. bring the old one, as there is a trade in 'core' value.
Disconnect the 12 volt battery and try to start it from the jump points, or just connect it to any good 12v you have around. The 12v could be so dead it shunting the system. If you do this and nothing lights up don't bother buying a battery, you have way bigger problems than the 12v.