I think I just blew my second inverter in a row... Help?

This is my first post, but I have gotten a lot of help by lurking here over the years, so first off thanks to the community for all the knowledge and experience shared. If you guys can help me out one more time and get this car on the road again, I will be so incredibly stoked. Here's my situation:

About a year ago, my wife's 2005 Gen 2 started showing the red triangle and intermittently not going into IG-ON mode. Usually, it would work after waiting a while. Occasionally, the 12v auxiliary battery would become FULLY drained, sometimes even after a day of driving (down to 3 or 4 volts, but its a deep cycle AGM battery so I didn't replace).

This was an inconvenience, but at the time I didn't have a code reader that would work on the Prius, so we just dealt with it. Then, we went out of town for a month, and the folks we asked to watch the car ended up having to jump it a lot... and when we came back, it was totally dead, non-responsive, no lights, no start nothing. So I charged the aux battery which was drained down to 3V, and started going through all the fuses. I tested and replaced several (HEAD I think it was called, and a few others), and the 120A MAIN fuse in the engine compartment. This brought the car back to life, but it now had the full constellation of death on the dash board. I now had techstream and a cable, so I read the codes, and followed the Toyota FSM troubleshooting which led me to the Inverter being the culprit. The codes were:

P0a08 dc/dc converter status circuit
P0a09 dc dc converter status circuit low impact
C1310 HV system malfunction
B2775 Interior Verification to theft deterrent ecu / smart key eco

So I bought a used inverter and installed it. This immediately cleared the error codes, and the car drove like normal for several months. However, after a week or so a new set of error codes with red triangle showed up:

P3000 Battery Control System
P0A85 Cooling fan control circuit low
C1310 HV system malfunction.

Again, I went through the FSM walkthrough for these codes, and found two problems: 1) the battery fan was bad, and 2) corrosion on a wire harness between the battery fan and the rear of the car. I replaced the fan with a new one and cut out the corroded wire and soldered and insulated it. This cleared the codes.

Then, a few days ago (about 1.5 months after fixing the fan issue), while my father-in-law was driving the car, he heard a 'pop' and all the dash lights lit up. The current error codes are:

P0A08-264 dcdc converter status circuit
P0A78-279 drive motor A inverter performance
P0A94-555 dcdc converter performance
P3108-535 Lost communication with ac system control module
P1498 communication malfunction A/C inverter local

If its helpful, I have screen shots of the techstream freeze frame information, but I'm not a mechanic and am sufficiently ignorant that I don't know what to do with it. I suspect there must be some underlying electrical issue that is behind this that I missed when I replaced the inverter the first time, but I'm not sure what. Has anyone dealt with this kind of repeated situation before? Or is this really a separate issue? Any and all wisdom you guys have to pass on is truly appreciated. I want to keep this car on the road if I can.

TL;DR:
During normal city driving, there was a loud pop, and the following codes showed up. This is after replacing the battery fan, inverter, 120A MAIN fuse, and cleaning and soldering a corroded connection in battery fan circuit:

P0A08-264 dcdc converter status circuit
P0A78-279 drive motor A inverter performance
P0A94-555 dcdc converter performance
P3108-535 Lost communication with ac system control module
P1498 communication malfunction A/C inverter local

 

So in your case a bad hybrid battery was the culprit? Replacing the hybrid battery resolved the issue for you? Did you also have the inverter, 12V aux battery, and battery fan issues I had earlier or just the dash lights and codes that I currently have? Thanks for the help!

 

Yes, I have techstream. And thanks, yeah it looks like the code is B1498, not P and I wrote it down wrong. How would you make sure the codes are correct? Would you just assume techstream read them correctly?

It seems like based on the intersection of all these possible trouble areas, the wire harness between the hybrid control ECU and AC inverter is a good place for me to start. Does anyone know the location of that harness offhand? Is it this:

 

Thanks, I'll keep you guys posted as things progress

 

Sorry for the lag in response, Its been a busy month for me. And thanks for the advice! As it happens, I have replaced the 12v battery 3 times in the last 4 years, and I would like to figure out the underlying issue that is causing this to happen along with the other problems.

An update: I took the car to a mechanic to get the issue diagnosed, and his opinion was that the hybrid battery was bad. He wasn't able to give me any specifics as to why this would cause the symptoms I have, or whether he thinks this is the root cause. I guess I'm not convinced he was thorough in his diagnosis. The battery passes the Dr Prius tests, and I don't have any battery-related codes.

Are there ways that the HV battery can fail that will throw these other codes, or damage some element of the HV system without throwing a code? I'd really rather not pay for an HV battery until I'm pretty confident it is an issue.