The Prius works off of a parallel system meaning that the gas and electric engines work beside each other. It picks up some of the slack from the smaller gas engine and helps the car accelerate and decelerate. If that battery fails, then you could still drive the Prius, but it will be weaker and a lot less smooth.Jan 13, 2020
7 signs your car battery is dying
New high-voltage (HV) hybrid batteries are usually overkill for your used Prius or Camry. Your Prius or Camry isn't worth the cost to replace the battery – you might as well go get a new car, right? Not so fast! MOST of your Prius or Camry High Voltage (HV) battery is actually fine.
Like every car battery, the one in the Prius will wear out - it is normally good for around 5 to 6 years but can last longer. Unfortunately it loses it's strength when left in place too long and will go dead much quicker if the car isn't driven daily.Feb 21, 2020
Signs of a Weak 12-Volt Battery in a Prius