2013 Prius 3 "Check Hybrid System Stop the vehicle at a Safe Place" message

Hi everyone, I just joined today. My 2013 Prius was running flawless until last night at 170995 miles. While accelerating the message "Check Hybrid System Stop the vehicle at a Safe Place" came on with the check engine and a yellow triangle with exclamation point lights. The "Ready" light is still on and I was able to shut off and start the vehicle 5 times completing deliveries then drove 90 miles home. Ever since the error message I noticed the engine is running constantly unlike before It only cycled when charging or full power needed. Once got home I searched Google for cause of this error and quick fix. Someone suggested disconnecting the 12v battery 10+ minutes to clear the message which I did but when I reconnect and try to start this time the engine did not start and with more if not all the warning dash lights came on and the "Ready" light never on. More googling suggested the 12v battery is weak/old about to die is causing this problem. Has anyone experience this problem and we're able to fix it. Any lead would be helpful, thanks.

 

Sounds like a plan I hope is the 12v battery. Thanks

 

After disconnected (10+ mins) and reconnected the battery it did not start at all with all the warning lights and the "Ready" never comes on. Took the OEM battery to NAPA and got tested and they said it's putting half the amperage (feeling hopeful the 12v battery is causing all of it). Went home installed new battery but sadly it's the same problem. Going to buy an obd 2 scanner...

 

Brought a code reader it gave 1 code the dreaded P0A80 faulty hybrid battery. Any chance a faulty or cut wire/cable would cause this?

 

Removed Hybrid battery covers and measured DC voltage at each cell with reading at each cell at least 9.3v. It seems the hybrid system failure is not the hybrid battery at this moment next I will be testing the inverter/converter and finally the coolant inverter coolant pump.

 

Just checked it looks new with no sign of corrosion or loosen.

 

Load tested with 65watt headlight bulb every module holding steady at 7.3volts

 

Very light white/light green build up around the terminals and bus plates. I just received a recall from Toyota for Hybrid software update and the severed end of it could cause inverter/converter to fail. It could be that causing all the dash lights on with the hybrid failure...