Questions on rebuilding hybrid battery, make sure I'm on the right track

Hi folks, looking for guidance to make sure I'm on the right track.

2005 Prius, 190k on the odo. Friend was throwing it away so I basically got it for a steal.

Was giving intermittent transmission code. Usually on long drives when the back was full. Led me to believe it was a heat issue and the battery. Former owner informed me he got that code a few times. Code never came when the back was empty. Former owner also had cells replaced.

I got the hybrid battery code for a few blocks, used a trusted source to do cell swaps, code came right back. Took it back to him and after working on it he described it as a cancer and would need a full battery pack swap or full cell rebuild. Got a lead on a gen3 battery with low miles (2012, 110k on odo). Did the full cell swap and got recurring hybrid code indicating blocks 8, 11 and 13, with 11 being the repeat offender.

Got another different gen3 battery, did the full swap again, and getting repeating block 11 as the guilty party. Reading more threads on issues faced with rebuilds, it seems another common culprit is corrosion on the copper contacts for the cells and wiring. There is a decent amount of corrosion across everything (the blue raspberry dust).

Checking resistance with the fancy Autel, and it's always 0.02 across all blocks, no deviation. Was the same with the other full cell swap. Revving the engine in park, it's always cell 11 that drops the most.

Is another possible culprit the copper contacts as well as the wiring? Probably take it out and clean everything this week.

 

Thanks for that. Given the amount of corrosion, will probably call the dealer Tuesday and order a replacement and then save and clean these for future use.

Cleared the codes and driven many times. The system isn't happy with something about cell block 11.

Temp sensors are working and reading correctly. I broke one sensor on the swap and ordered a replacement from ebay, replaced and it's operating as intended.

What's the spec on the 8mm nut for the bus bar?

 

Thanks, just needed the value. Time to order, replace, torque and see what happens.

 

Annoying thing there is need an android phone.... silly apple...