I bought my first Prius in 2010 which was a new level 2. I kept the car for 5 years and it was a great dependable car. It ranged from 47-52mpg. I decided I wanted more bells and whistles so after 5 years I traded my 2010 in for a 2011 level 5 which I have had for 3 years. I have never been able to get as good of mileage in my second Prius. Currently I am getting 37-42mpg. The car has about 89K miles on it. My 12V battery was replaced less than a year ago with no change in mileage. Running Michelin Premier A/S 215/45R17 tires with 38/36psi. Mainly drive the car to/from work which is 16 miles each way, 70% freeway driving with some hills. I have read postings from people that have warnings go off while in a car wash because the car is in neutral and battery gets depleted. The warnings let you know the car needs to be put in drive or park so it can start recharging. Never had this problem with my first Prius but my current car does it consistently during the summer (desert heat=AC). It does not throw any codes just gives the warning. I brought this up at the dealer during my last oil change and he said some vehicles are just that way. There are no error codes to say anything is wrong. I really think my hybrid battery has bad cells but enough good ones for it to function properly most of the time. I have seen there are companies who will pull your hybrid battery and test individual cells and refurbish any bad cells. Is there anyone who has done this who can tell me of their experience, most importantly did it help with mileage? I have seen an estimate of $1200 as a starting point to have this done (gulp). I have read testimonials online from shop websites but figured this forum would be less biased and honest. Thanks…
At worse, you are getting 10 less mpg on your nicer Prius with 17" wheels. The wheels and older HV battery definitely contribute to your problem. But if you do the math, $1200 to make up 10 less mpg, it's not working in your favor
I've seen brand new cars do it too. All it has to do with is if the SOC of the battery drops enough the car wants to recharge it. Simple. But the car can't start the engine to recharge the battery when the car is in N for obvious safety reasons. So it does what it can and whines at the human, "hey I wanna charge and you won't let me". It will continue to whine and complain until it can either start charging OR the battery gets so low that is can no longer start the engine and then you'l get all sorts of errors and codes in a "I told you so" way from the car. Getting this message is not inherently bad. And in the summer with heavy AC usage you are probably starting the drive through the wash with a low battery like 2-3 bars where it wants to recharge anyways and you're saying no by putting it into N. If you're worried about it, just force charge before you go through, or turn off the AC. Don't really need it at a carwash that pulls you through. It is likely you have severely deteriorated cells, as the car is going on 8 years old. A 2011 was built in 2010, so 8 years. You may have bad cells, but the way I read your timeline is you bought a brand new 2010 so in 2009-2010. Then in 2014 or 2015 bought a used 2011 and for the past 3 years you've never been able to achieve similar efficiency as your 2010. Could be many factors, even something as simple as a bad alignment. But a battery problem should manifest in worst than normal mileage, whatever your normal is. Your normal is lower than your old normal but it hasn't waivered from this new lower normal for 3 years. That's enough for me to say your battery is in good enough shape for an 8-year old car which is starting to creep up that bathtub curve of failure and death. As to is it worth it...
