2006 Prius bad battery pack?

I just got a 2006 Prius for $900. I knew it would be a project, and I'm just looking for some help from the Prius community.

I was told that the hybrid and 12v batteries are both bad. The 12v one wouldn't charge past 10v, so I got a new one of those. The hybrid battery case really looks like it has been tampered with, so it seems very likely that is an issue.

Upon starting the car as I got a ton of error messages, lights, and it wouldn't turn the engine on or ready up (as expected). I hooked it up to Dr. Prius and found the pack voltage at 158v, and it looks like some of the cells are not working right. I also got error codes P3000 (which I'm not familiar with) and P0AFA.

I also tried putting the car in maintenance mode to run the engine alone, but with the pack being so dead, it wouldn't start and the MFD screen showed the word "Problem" really big which I thought was kind of funny.

My next course of action is replacing the entire battery pack and management computers as an assembly. Does this seem like the problem to you more experience prius people? I've only owned a few of these. Also, is there any special programming or coding that has to be done to pair the new battery pack to the car?

 

Hopefully, some of these attached images are helpful:

 

I did end up ordering a battery pack from eBay because I wanted to have one ready by the time I got back from my little vacation. This is a refurbished one (risky I know), but it was used in a car for a year and taken out because the car was wrecked.

I put the pack in today the car did start, but I'm getting weird behavior from the Prius and some similar symptoms from before. I was able to drive it around a bit but had no power in reverse and no power until the ICE started. (Seems like no battery power at all but ICE could crank hmm) I also observed the battery getting hot (up to 150F!!) and the fan running, and the state of charge was jumping in between 100% and 20% sometimes on Dr. Prius. I also still do have P3000 and P0A80

Could the inverter be bad? What is this? I do have a pretty advanced scanner that might be able to get the subcode on P3000, but I won't be able to try until the morning.

Feedback appreciated. Thank you

 

Thank you guys so much for the valuable feedback and advice.

I am in contact with the guy who sold me the battery. He's super understanding and willing to give me a full refund. I must note the battery case was pretty bent up during shipping which I assume could cause issues, but I was really hoping it would work. The car did start and seem to have electric motor power for a little bit before it eventually wouldn't move in reverse and the engine would start before moving forward.

While starting a search for another pack, I also don't want to rule out other possibilities yet. The battery pack was sitting in the hot sun for about 20 minutes before I put it in the car, so that should explain the high temperatures. The weirdest behavior I observed was the SOC changing from 100% down to somewhere in the 20s or even bouncing up to the 80s. It would instantly do it as well while just sitting in park. Could this point to a control module or sensor instead?