2012 Prius V: SOC Dropping Intermittently And Instantly And Throwing P0A80 Code

2012 Prius v, 209k miles

Last year I replaced two hybrid battery blocks that failed. Two months ago I replaced two more hybrid battery blocks that went bad. I also replaced the voltage sensing harness and primary ground cable because of corrosion. Things have been working well and suddenly, 1,500 miles later, this has started.

Yesterday, cranked up and turned on Dr. Prius. SOC was 58%. I pulled out of the driveway and suddenly the dash lights lit up and my SOC dropped to 27%. It was showing an active P0A80 code. I cleared the code and things started working. About 30 minutes later, it did the same thing.

Today while driving we stopped for about 20 minutes. Dr Prius was showing the SOC at 70%. As I pulled out, the dash lit up and my SOC dropped to 27%. I cleared the code and things started charging. This time the Delta SOC (red) started increasing as we were driving. You can see where I cleared it.

Later I hooked up my Techstream. All block voltages were fine. SOC was 56%. Suddenly, it threw another P0A80 code and my SOC dropped to 26%. Block battery voltages dropped down into the 15 volt range, but there were no significant differences between the voltages.

I am at a complete loss as to what to check next. We're leaving in 6 weeks for a 6,000 mile trip...and I can't leave home like this! Video link attached.

Any input or suggestions would be appreciated.

Thanks!