Dreaded P0A80 Code - Car Running / Charging Good.

1. 
   The battery pack is made up of 28 modules that are all connected in series. So, the pack is only as good as the weakest module in the pack. (I am keeping this simple and not getting into the fact that inside each module is 6 cells that are wired in series.) As the battery pack charges and discharges, heat is generated due to the resistance of the battery cells. The modules in the center of the pack get hotter than the modules on the ends of the pack. This heat is what causes the battery modules to degrade over a long period of time. The center modules will degrade at a faster rate than the modules on the ends.
   
   Looking at the freeze frame data, two things stand out to me.
   1. Block #8 is much higher than any other block in the battery pack. It appears to me that one or both of the battery modules in that block were replaced by newer used modules by someone.
   2. There is a large voltage difference between the battery blocks.
   
   A health battery pack will have a voltage difference of 0.30 volts or less between the battery blocks. To me, it appears that this battery pack is not in very good condition.
   
   The freeze frame data shows that the battery pack was being discharged at 29.10 amps when the P0A80 trouble code occurred. That is a fairly low current draw. During hard acceleration or high regenerative braking, the current flow into or out of the battery can easily be 50 to 75 amps. As the current flow increases, the voltage difference between the battery blocks will also increase.
   
   I am guessing that most of the battery modules in the pack are the originals from when the car was built 10 or 11 years ago. So, those modules have 260k miles on them. That is a lot of miles for a battery. Batteries do not last forever.
   
   You could try to refurbish the battery pack by charging and discharging each module 3 to 5 times to determine the capacity of the modules and decide which ones are good enough to keep and buy used replacement modules to make a good battery pack. This will take you 3 to 4 weeks to do correctly. The refurbished battery may last a month or a year or two until the next P0A80 code occurs. It is a gamble.
   
   In my opinion, it is not worth the time and effort to refurbish a battery pack that has 260k miles on it. I would replace it with a new OEM battery (if you plan on keeping the car for 5 years or more) or purchase new cylindrical cell design battery (if you plan on keeping the car for 3 to 5 years) or a refurbished battery ( if you plan on keeping the car for 2 years or less).