2006 with 78K miles, new Optima 12V battery and clean battery fan. I have installed 3 Dorman batteries, returning each one after getting a DTC P0A80 right after installation and test drive. I took it to the Toyota dealer and they signed off on a battery failure on battery #2. The P0A80 is usually accompanied with another DTC. I have gotten: P3021 and P3011. After 3 replacement HV batteries, I don't think it is a HV battery problem. I have replaced the HV battery on 2 other Priuses with no problems so I don't think it is my installation technique (but if could be). I think it might be a Hybrid ECU problem or a bad connection/wire somewhere. I am stumped and would appreciate any ideas on diagnosing this problem Prius.
