I have a 2011 prius with 211
I have a 2011 prius with 211,000 + miles. Never a problem with the hybrid battery. Still using original 12 volt it came with. Keeping the air vent from getting blocked, not driving with windows down, and not smoking prevents dust and such from getting sucked into the hybrid battery area and collecting around the cells which in turn overheat the battery causing failure. I also can still go at least a mile in EV mode. Sometimes farther.