I have a 2018 Pacifica PHEV. After driving 29000 miles, I found yesterday the car is completely dead. The instruction manual said that I needed the 12V juice to power up the car and the high voltage battery. I Found the terminal on the battery is loose and came off when I touched it. I tightened it and jumped the 12V battery, which is tricky, and the car started. I then drove the car for 3 miles - both on electric and gas - and when I stopped, the battery was dead again. Jumped again and drove it to the dealership which is 9 miles away and when I turned off the ignition, the battery is dead once again. The dealership told me today that they have to replace the battery. They can diagnose the problem only after they replace the battery. My question is why do they have to replace the battery withing 2 years and why is it not charging when I drove the car and also, when I tried to charge it with my booster charger it was not charging.