Folks, I hope you have a suggestion or two for this long time reader - but new poster. My 2005 Prius went dead completely. I went away for 12 days and then, it started only with a jump. A note about the jump battery process: I was distracted on the street for a minute or two and left the jump battery on the terminals. When I looked in the car, the dash was all lit up. I then shut the car off, and it wouldn't start again - except with another jump. After driving it for 10 minutes, I parked and shut it off. It wouldn't start again without a jump. It's all black at the dash and I have to let myself in with the key itself. It has a 3-month old 12 volt battery and a new key fob battery. Is this something that might be cured by taking the 12 volt battery off the negative terminal? What are your suggestions?
If the 12v battery is empty you will need to charge it. There is a small chance the battery is destroyed but I believe it should charge and recover if it’s just 3 month old. I had to drive mine 2 hours to completely charge on the car.
Ideally you would connect the car to a good battery charger (some type of "smart" charger that specifically says it works on AGM batteries) and charge it - that can take many hours, even overnight. Then have the 12V battery load tested at a shop (some parts retailers will test batteries as well). Even a new battery can be defective. If the battery checks ok but goes dead again, then you will need further testing to see if some electrical problem with the car is discharging the battery. Posted via the PriusChat mobile app.
What made you think it would only take 10 minutes to charge fully discharged 12v car battery? Posted via the PriusChat mobile app.
THIS! I have the same issue with my 2005 pri. Have had this issue on and off for years now. Recently i went on a road trip and every time turned the car off i had to jump it. But now it just wont start. (i should add my positive battery terminal thing was cut off completely and the HV battery exploded and brake accumulator failed when i found this prius) it also had the MFD intermitnedness but i think that was caused by my AUX port addition to the radio.
