Dreaded P0A80 Code - Car Running / Charging Good.

Of course cleaning each post is important also.
Prolong is a lot less than a new battery, no matter which one you get.
But, replacing it will mean you won't have to worry about the hybrid battery
for many many years.

 

Yes, the serial numbers are on the top of each module.

 

Yes, if three of the modules have completely different serial numbers, I would guess that they are replacements. Based on the pictures of the battery pack that you uploaded in post #112, I would guess that modules #14 and #16 are replacements.

Can you please provide the serial number of one of the common serial numbers and the other three completely different serial numbers? What position are the three different serial numbers located at?

 

So most are 16 years old and a few are 14 years old. That's a good run.
Start saving for the Sodium Ion Hybrid battery now.....

You got a lot of life out of that pack. And depending on when those older ones were replaced,
the newer ones are likely putting more stress on the older ones.

I think they new bus bars will likely help. There is no telling how long the pack will last.
So you need to decide on what to do next. Purchase the Prolong system and run the pack through
the complete 4 charge 3 discharge cycles to refresh it and see how it extends the life of the pack.
It extended mine for a few years. Allowed me to save up for a new one.

Just remember, it will fail at the worst time.

 

Thank you for the information that I requested. Your 2015 Prius with 260k miles has a battery pack with twenty-five 2010 battery modules and three 2012 battery modules. Very interesting.

Do you know how long the car sat unused before you bought it?

IMO, replacing the corroded bus bars will make no difference. I am assuming that all the nuts were tight on the existing battery pack. If they were, the nuts and the flange on the battery terminals were making good contact to the bus bars. This can be seen in the pictures of the bus bars that you provided. There was no corrosion on the bus bar where the nuts was located at and on the other side of the bus bar where the battery terminal flange was located at. You see it all the time in this forum where somebody says that you need to clean the corrosion off the nuts and bus bars. As long as there was good contact between the nut, bus bar, and battery terminal flange, the corrosion, like seen in your battery pack pictures, does not affect the operation of the hybrid battery.

 

Back in January it was clear the new to you Prius had a "repaired" battery, but it was missed other than "cleaned before" and missing fasteners (info provided later). A lack of knowledge on how to confirm this and a lack of trust lead to 7 pages and counting.

It will be interesting to see if the bus bars will allow the Confirmation Driving Pattern to clear your permanent code.

Honestly I hope it does. However, as Brian noted, a gas tight busbar connection usually keeps the voltage drop caused by a bus bar very low.

As stated before, the Confirmation Driving Pattern stress tests your battery before allowing a code clear. If the battery is weak, it fails.

If it fails, then its back to the most common issue, worn out modules. Which is expected from a battery that required used replacement modules sometime before it was sold.

Confirmation Bias is a tough nut to crack for some people. A psychological roadblock unrelated to a Confirmation Driving Pattern.