Hybrid Battery Status, Invest More Money?

That battery looks great but it's cold and not being charged or discharged while driving. It would be helpful to see the voltage spike when regen or drop when accelerating. Your IR is very low 19 mOhms, so that's a very good sign. My 2009 with 350K miles has an IR of 23 to 24 normally but it if it gets too hot, that can rise to 27 or 28. If it hits 29, that indicator goes yellow because that's getting up there. If I'm driving hard in the summer, I know temps will go over 120F if I don't use Dr Prius to override the fan threshold temperature and that only works if the app is actually running. I always have the app running if the module temps could get anywhere near 120F.

I changed my brake pads and rotors at about 280K miles for the first time. I didn't flush the brake fluid until about 330K miles. Turns out it wasn't necessary. Unlike typical ICE brake fluid, this came out of the calipers perfectly clear, with less than 1% moisture and 0 ppm copper. But I guess it's piece of mind.

Everything else is original except the coolant diverter valve which I replaced years ago for $73 (factory part but from amazon). I replaced the entire leather interior about 3 years ago with extra stock I bought from a San Diego Toyota dealership back in 2010 for 90% off. It was something like $300. So the interior looks new again for the most part. Replaced the floor mats twice. The second time just the fronts with the factory Prius black all weather mats since the factory carpet mats were no longer available the second time around.

 

FYI, the internal resistance (IR) of the battery blocks defaults to 19 mOhms any time the 12v battery is disconnected. It takes some time for the car to learn the actual IR after the 12v battery is reconnected.