Master warning, check engine, VSC, and brake light came on today

I have a 2005 Prius. A couple of weeks ago all of these lights came on so I took my car to a mechanic. The issue was that my hybrid battery was dying so I paid 3.5k for a refurbished one. The car has been driving great with better mpg. Today I was driving for about an hour until the same lights came on. I called a tow truck and had to pay a whole bunch of money. My car is sitting at the mechanic over the weekend until they open again. Even the tow truck driver said that it seemed to drive fine but all he did was park it. Obviously, I know the mechanic should be able to diagnose the issue but if anyone has any idea of what is going on I'd appreciate the advice. I'm considering selling the car even though I just got it in July, but all of these repairs are expensive af!!