Hello! I have a 2007 prius with 180K on it. I’ve been overseas for a little under a year, so my mom kindly drove the car every week or so for 30 minutes to do errands while I was away. In the last few months though, the battery died several times, after being jumped by AAA and then driven to recharge. Initially, AAA said battery needed replacement, so my mom went ahead and did that, later finding out it was perhaps the incorrect battery they put in (the car died again within a few days). She then took it to mechanic and they replaced the battery that AAA put in (12V I believe? It was around 250) and it died again not long after and AAA jumped again. Mechanic then ran diagnostics and said my radio/sound system was a parasitic leak on the battery, so they removed it entirely. It died again. Mechanic said they couldn’t diagnose anything else wrong and that I should take it to Toyota. I bought the car used and think that bringing it to Toyota would likely cost me thousands and maybe replace things that aren’t necessary. I was out of the country when all of this went down, and I feel like there were several things that were potentially problematic and that I have questions about. My car is quite low on mileage and it’s spring/summer. I replaced the 12V 2-3 years ago already, and haven’t had ongoing problems with it. It died once or twice in the snow a few years ago. Prior to going abroad, I traveled for 8 months nonstop though, and never had an issue with it. Some questions for those that know way more than me: - Is it possible that when my mom was running car after a jump, it wasn’t charging enough and that’s why it kept dying? Was once every week or every other week not enough to be running it while I was away and that’s the issue? - Would AAA have damaged my car by jumping it incorrectly the first time? In some threads I’ve noticed that could happen. Is it possible that their incorrect battery replacement also damaged the car or made it unable to keep a charge? I’m not even convinced it needed to be replaced initially when AAA suggested it, and I wonder if this is the source of my problems. - Since the 12V is brand new, what other reasons could there be for the constant dying? Is it possible that the other expensive battery needs replacement? I read about replacement of cells rather than the entirety of it, could this be a good next step? Ive been reading Prius chat for years — I find it refreshing and helpful as someone with limited car knowledge. I am anxious of being taken advantage of at mechanics, and despite some research on my part, don’t feel like I can truly advocate for myself or ask the right questions so I don't end up paying for things I don’t need. I have no clue what’s going on here and would love some guidance so it’s back and running and I can avoid the dealership. Thank you so much for the time you took to read this and any suggestions or insights would be really helpful. Thank you so much!! Also, any recommendations for reputable mechanics that work with hybrids in the ME/MA area would be super helpful as well.
Want to kill the 2 Battery's in a Prius?: Don't drive it. much. Running to the store will not put much of a charge on either battery and once a 12 battery dies and sits a zero volts for quite its never the same. I wouldn't worry so much about the 12 volt battery that's a cheap fix whats really going on is your killing the hybrid battery. That's a whole different and very expensive battery. Dead hybrid battery on a Gen2 is the most posted thread on this site. Its just time there all 16 years old. Btw, is your Prius a Touring model with leather seats and the JBL sound system?
Quite true for the 12 Volt. But the HV hybrid battery is a different animal and infrequent driving should not have any terrible adverse impact on it. Can you provide any solid evidence that it WILL ?? Or even any good anecdotal reports from owners ? I think you are blowing smoke again. Now having it sit totally unused for years likely is a different story.
there's no relationship between the 12v and the hybrid battery. you need to do some testing, do you have a volt meter?
My car doesn’t have leather seats, not sure about sound system. Don’t think it’s a touring model. Obviously you can’t know, but does it seem like the hybrid battery is the one that needs attention? Thank you both.
Something is wrong with the 12 V system. Either the inverter isn't charging the battery....... OR your new batteries aren't ever being fully charged....... OR there is a loose or corroded main cable connection....... You NEED to take it to a shop that is qualified to work on hybrids so that the problem can be properly diagnosed. While it is possible that the HV battery is getting weak, I think it unlikely at this point. BUT at 16 years old, that probably is the next headache you can look forward to. Have you considered trading it in ?? If not, maybe you should.
