I replaced 3 cells in my gen 1 battery. Put the HV battery back in and went to install the orange fuse link. It basically exploded. Presume that there is a short in the pack. Maybe I put something in backwards. No injury sustained, but it showed that there is a lot of power involved. Now I need to figure out what's wrong and if it can be salvaged.
Open it up. See if polarity is correct for each module. How many modules were unbiased in order to replace the bad modules. Share some pics of pack that show the + and - marks in the modules.
Situation Fixed! Full disclosure - The original post omitted some information that may be relevant. In order to help others avoid my problem, the full story is here. After I put in the repaired battery, I attempted to start the car. Unfortunately, I had forgotten to put the disconnect plug back in the battery first. The car started but had a lot of error messages displayed on the dash. It was also quite unresponsive. I then discovered that I had forgotten the plug. I disconnected the 12v auxiliary battery and went to put in the plug. It was then that the plug shorted and burnt out. I took the HV battery out and checked it. All modules were in correctly. Nothing looked bad. I watched several videos showing the battery replacement process to get some help. I could not find another case where the plug had shorted out. Anyway, Dorman videos are very helpful. I noticed that in those videos, they do not disconnect the 12v auxiliary battery. So I connected mine and put the hv battery back in the car and put the disconnect plug back in. It worked. No arcing. Now the car started perfectly with no displayed errors. I had ordered a new disconnect plug from Toyota. "Grip, service plug". Part number G3834- 47020 for 2001 Prius. $4.30CDN. Took 12 days to arrive. Prior to installation, I took out the receptacle and cleaned up the connector to ensure a good connection. This was instead of buying a replacement receptacle.