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?
It sounds like your only problem may be the 12 volt battery, The traction battery is starting the gas engine not the 12v.
The simple answer is no, the Prius cannot be driven as a conventional gas car with a completely dead traction battery. The traction battery also provides control power to the constantly variable transmission (CVT), and the car is dependent on that. That said, it's not a given that your traction battery is dead. The car also needs 12V to run, and it needs the inverter assembly to be working to charge the 12V. Check voltage at the battery or jump terminal when the car is "Ready." Should be about 14V. If the battery has been completely discharged, it may be toast. Do you have a check engine light? If you're going to be working on the Prius, get yourself set up with the MiniVCI on an old laptop. It's what many of us here use to diagnose, monitor, test, and even customize the car. Is the traction battery vent fan (grille in the back seat) running? Do you see widely varying state of charge indication on the display? These are indications of battery failure. Florida heat may shorten battery life. Be extremely careful to jump the car correctly.
Both Toyota and a number of aftermarket vendors sell a Prius battery. It needs to be an externally vented AGM battery with JIS posts, the buzzword for that is S46B24R. $201 Advance Auto Parts - Store 4628 412 North Duval Street Tallahassee, FL 32302 850-222-8780 CARQUEST Auto Parts - Store 1622 1830 Capitol Circle NE Tallahassee, FL 32308 850-877-8223 $180 Oreilly 2450 Apalachee Parkway Tallahassee, FL (850) 656-3870 As examples that claim to have one in stock.
I think you should remove the dead 12V battery, then jumpstart the Prius w/o a battery. See if the car can be driven. The dead battery may be excessively draining the electrical system.
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.
Unplugging the 12v resets any trouble codes so after installing the new 12v battery I would suggest a good long test run around town with fresh gas before heading home. If no codes, you should be good to go then. Check tire pressures too.
I gave Tallahassee auto parts stores, do you want Jacksonville stores with the battery in stock? $201 Advance Auto Parts - Store 9297 3794 BLANDING BOULEVARD JACKSONVILLE, FL 32210 904-771-6777 $180 OReilly 8220 Atlantic Boulevard Jacksonville, FL (904) 723-3617
