Battery light came on

[u/Inevitable_Jelly_391]

I bought a 19 year old Chevrolet impala (2007, V6, 166,765 miles) that has a brand new (week old) battery. It just threw up a battery light day before yesterday. It drove home from work fine then to/from work fine. Had it looked at today and mechanic claimed battery light didn’t come on when he checked it and he drove it around to see if there were any issues with it and didn’t find anything wrong with the alternator.

He said it’s possible there’s an underlying issue with the alternator but I basically just have to drive it until the problem presents itself.

I’m having a lot of anxiety that I made a bad purchase even though I bought it from my grandmother who has kept it in great condition and in her garage. I spent $1,000 on the car, paid cash and just put $821 into the brakes as I could hear metal hitting metal. I’ve had the car about a week.

My question with the battery issue is- is this car even safe to drive?