HV battery or 12v?

I have a 2006 Prius with 230,000 miles on it. Yesterday the car had the bank of dash lights come on including the red triangle of doom right after my husband started driving out of a parking lot. Prior to that no symptoms, no loss of gas mileage, car has been running great. He did the right thing and pulled into another parking lot, and called for a tow. Since it was Saturday we had to take it to the dealership. The dealership says that it has P3000 and POA80 as the ONLY codes. Of course the dealership is saying that the HV battery is dying. BUT I have had a similar problem twice before, where the HV looks like it is failing to charge and thanks to smart people here at Priuschat I just had the 12v replaced and all was well. Today they tell me that when it came in to the dealership they said they charged the 12v (so obviously that was low) and then reran the diagnostic which came back with the same two codes.

Now what I want to know is if the 12v is not holding a charge can that cause those codes to throw even after it was recharged, quickly as they came back with the codes within an hour of getting the car? Second question is whether it is typical for an HV battery to not have any loss of gas mileage or other symptoms prior to throwing those codes? And finally whether it is typical for a bad HV battery to throw ONLY those codes and no others? Thanks!

Dealership is pushing really hard to get me to buy a new HV battery for $3000 plus install.

Note: the value of the car is below or equal to cost of HV replacement.

 

Same Prius, in 2011, and 2016. The 12v seems to last about 4-5 years here in the desert. I have read that the usual list of symptoms of the battery going includes lower gas mileage, ours is GREAT! That is why I am suspicious of sudden death of the HV. It has been treated well, lives in a garage, does longer drives rather than short trips. Yes we are near or above 100 for 5 hellacious months of the year. Also the timefor a new 12v is here and when it came into the shop the 12v was low.

 

Ok, the code was a typo on their side, I just copied and pasted. YES! They have not told me which cell(s) are bad, they just want to sell me a new battery pack. I did ask about additional codes, the service guy claimed those were the only codes — huh? Of course they wanted to sell me some additional services that I don’t need as well.

If you know of a shop with better prices in southern AZ please let me know. No the Prius has not needed anything else besides the recalls (done) and a water pump ... and a master wiring harness (packrat damage).

 

Ok, another question (number 5): IF it does need an HV battery replaced, and assuming by some miracle the money to do that fell from the sky, what kind of value would it have? It has been remarkably trouble free.

Question 6: I have done a few things before DIY, fixed a broken antenna using info from this site, for example but I think doing the battery pack might be beyond me. However I may be able to find someone who likes to play with Prii. If I can would you recommend replacing just the bad cells and reconditioning? Or replace the whole thing? Does replacing the whole thing with new increase value at all?

Thanks!

 

Ok, I basically have three choices. 1) Put a new 12v in and see if it pops codes again, which it should if the HV battery is really bad. But if it doesn’t then maybe it’s a bad 12v. Cost $250. 2) Put a new battety pack in at the dealer, because it’s there. Cost $3000 assuming they don’t insist on doing other things. 3) Get my chiropractor, who has done this with his Prius and has volunteered to do it with mine, to use his equipment to figure out which modules are toast, replace those, and float the pack. Cost probably $500 because I would pay him for his time. Which would you do given the age of the car, miles, and no other major repairs ... yet. Please include your reasoning. Thanks!

 

Dude, that was 4 years ago in one case and 9 years ago in the other.