I see that the plug in prius has a 4 kw lithium battery. Does this battery also charge when the gas engine is running, just like my prius?
Yes. It's just like a Gen III Prius with a bigger battery. The difference is that the battery is Li-Ion instead of NiMH and you can plug it in to charge it. The Plug-In will also go up to 62 MPH on battery only (EV Mode) for 10-14 miles. Check out Mark's mileage with his new Plug-In.