Self induced "Check Hybrid System" ....

If you had those codes and a DTC list originally it would have saved you some stress. Really what you might consider is the Mini VCI techstream assuming you have a laptop and you will be ready for anything. Attached is a screenshot of your code explanation and a 2010 Prius DTC list (essentially the same for any gen3)

 

I would not worry about it too much on a 2011 with 79k miles. Maybe at 150k miles. You are probably still in hybrid system warranty (100k or 150k depending on state). Toyota suggests 0.3v is an acceptable module to module difference, charging or discharging. Your snapshots are well within those parameters. And then individual modules are allowed a 2v charge discharge swing (with all modules staying within the 0.3v). Your battery has its own ecu on the network which measures each module in realtime, it is also measuring several temperature points on the battery and controls the battery fan speed. Some recommend opening up the back to clean the battery fan especially if you carry animals.

If you want to know more than the service advisor about hybrids, try Weber State youtube videos. This is a good one to start on:

He also tears down a 3rd gen battery here:

 

Glad you're finally using an app that's designed for your needs... You might want to use hybrid reporter via hybrid assistant app and drive an easy to repeat route with some hill climbs and some stop and go and freeway speeds to. Then get hybrid reporter to print up all the data and save it for 80K miles from now. Then drive the exact same route, same outdoor temp, same time of day and you'll have tons of charts and data to see how the hybrid system and overall vehicle is doing as it ages.