Well, assuming your wiring is up to snuff, you'd only need to charge a PiP at night and for 3 hours max. There's also a charge timer built in so you can (and should) delay when it starts charging. Your power usage is low when sleeping, no? Unfortunately, I'm the wrong guy to answer your other questions. '12 Camry Hybrid is a big improvement over the previous gen. Much faster (due to having more power), better mileage and a larger trunk.
