Traction battery?

I have crossed over the 230k mile mark with my Gen 3. I have not had any indication of a battery issue, but I’m seeing a decline in overall mileage. In the spring I was 51-52, now barely 40. With the scanner app I have, the battery voltages are running in the added picture.


I was thinking one of two options, given I’m not 100% sure that I will keep the car much more then another year.

Option one, salvage yard battery from a 2016-2018 NiMH equipped Prius. Available in reasonable distance for $800 with no core.

Option two, a greentec auto refurb with a 12 month warranty for $1k.

If option 1 is possible, I could individually test, charge, or replace any bad cells in my current pack at my leisure. I was pretty sure that I have seen a thread on here talking about rebuilding a Gen 2 pack with Gen 4 cells. And eBay is chalk full of Gen 2/3 cells for sale. Is a Gen 3 battery rebuild a possibility with the Gen 4 cells??

Option two, greentec has a location about 2 hours from me. As far as I know, they come to me to do it, and they charge upfront for battery and core, with the refund after the fact for the core.

At this point, it’s easier to come up with the 800-1000 to repair it now, versus the 1700 for the new battery, or the 250-350 monthly times 5 years or so for a new car.

 

I paid the $12.99 for the Dr Prius test. The result is here. Looks like a hybrid battery is in the near future.

 

During my morning drive, the battery bars in the app were green for the most part. Hard accel or decel turned them yellow and red. The pack voltage was as low as 180v and as high as 265v. When that number is highlighted in yellow and red, I think it’s safe to assume that’s bad.

 

So after verifying everything on my car that I can check, 12V, coolant level, tire pressure, and driving habits, I changed filling stations, to another location of the same brand that offers E0 fuel. There was a note on the door that the last three fills from their supplier that they “might” have received sub-par fuel. “While many people may not have noticed any issue, if you fueled at one of our locations between 11-10 and 12-8, you likely got some of this fuel. If you can produce a receipt, or credit card statement, we will refund the fuel cost to you. In addition, if your car required repairs, our supplier has a claim form for you to fill out”.

This fuel tank has started out in the lower 40’s. A substantial improvement.

 

If the improvement continues, I may look into the Prolong equipment instead of the traction battery.

 

March will make 2 years. 230k on body/battery. 8-10k mile short block installed at 213k in July of 2018. Until a month ago high 40s to low 50s MPG in town. Dropped off to as low as 37mpg indicated. Never a light or other indicator of an issue. The last 100 miles or so, it’s back to showing 44-50 mpg. The last “major” thing I did was pull the thermostat a week ago, as it wasn’t heating the cabin as well as I remembered. Found the t-stat clogged with stop leak from the leaky head gasket that it had when I purchased it.

 

And the internal resistance values are 22 milliohms except block 1,10,12,, and 14. Those blocks are running 24.

 

So I guess that the thermostat issue I fixed was causing the car to not reach operating temperature. Long term fuel trim is running -2.96 to -3.16. It started at 7.56. Fuel mileage is climbing. Up to nearly 46mpg indicated even with heater set at 74 degrees.

 

I went on a 1.5 mile drive sans heater just to see, and the cons number climbed .8 mpg. So the Prius seems to be pretty sensitive to engine temps as they relate to overall efficiency. I guess it showed itself as temps fell and stayed below freezing in my area for a prolonged period.