I reconditioned my hybrid battery - by accident

I managed to overcharge or overheat the battery and trigger "Check hybrid battery cooling system" on the long downhill in the Alps. The battery level shows solid full but then I stop and monitor the temp with Dr. Prius. It was about 58C and no more warning after that. I should put to B mode or cruise so the car select automatically to B when it's full. The ECU is not smart enough in D mode not to overheat the battery

 

You should check the fan, and vents.
I don't believe the Prius computers will allow the battery to be overcharged.

 

Probably it is just mildly overheated in summer long 20 minutes downhill. I also doubt it is overcharged too. I removed the add on filter (fiberglass like) that I made behind the clip on screen on the cooling intake. It was there for more than 1 year without issue until my Summer vacation in the Alps.
I remember 3 years ago, with the old rusted brake disc I experienced vibration after long downhill. But after disc and pads replacement, it never happened anymore.
I think in D mode the ECU still allow recuperative braking but not 100% as when the battery is not "full".