Semi-dead Prius

My Question: Is there a way to run the Prius as a conventional gas car, if the traction battery(ies) are kaput, but if it has a fresh 12v battery?

The story:

I am helping a widowed friend restore her late husband's 2008 Prius to running order. It, until yesterday, sat unused for about six months. And it is located about 200 miles from where it needs to be.

I'm reasonably handy with a wrench, having done mechanical things most of my life, and I'm very generally familiar with the Prius, but not details.

Yesterday, I "jumped the car off" with a my conventional car's 12V battery, and was able to drive the Prius around the block several times and it performed normally. Perhaps too normally. That's because any time the Prius decided that it was wasting fuel, it would attempt to switch over to electric power. And with that, it would stop dead and could not be revived w/o a fresh jump. That is, the gasoline engine would quit, and would not restart, unless I jumped it off again.

I could not get the 12v battery in the trunk to hold a charge, and have pretty well determined that it is well past its useful life.

Moreover, I am guessing that the traction battery(ies) is or are either worn out or are completely discharged.

My plan is to replace the 12v battery, and attempt to drive it -- perhaps the 200 miles -- home. Once it's in my workshop, I could then address the traction battery.

So to ask the same question differently, how do y'all suppose that's gonna work out?

 

Very interesting! When I cautiously drove the car about, I don't think it had a check engine light. And to be very frank, I was preoccupied with driving a completely unfamiliar car as well as preventing it from croaking out in traffic. So I did not observe any of its many displays on the instrument panel.

I'm surprised that the engine starts with the traction battery. do not know why I'm surprised, but I am. And it is good news because when the Prius had a surrogate battery -- the widow's Subaru battery, in situ in the Subaru -- the Prius gas engine started. So from that, and from your answers, I infer that the traction batter(ies) are not completely toast.

There seems to be a consensus that the Prius should get a fresh 12v battery, and that it shall have.

Thanks for the thoughtful and on-point answers. Something of a rarity on-line fora.

Any further comments, etc., much appreciated. BTW, I have no plan to become Prius literate, aside from plucking this example from its former home in Jacksonville, Fla, to its new home in Tallahassee, Fla. (home of good ideas.)

Thanks again!

P.S.: if/when I am able to drive it to TLH, I'll report my results here along with any difficulties.

 

Good advice! I should have mentioned that the LR tire is low. Scary low. Thanks!