Electrical Help Please

OK Mike, Here's what I did............
1. I checked the voltage with a meter at the battery with the car off. It was about 12.5v.

2. Then I started the car and it went to about 14.25v.

3. Then I started the car and removed the negative battery cable. The car didn't die. I let it run 5 min. or so.

Seems the alternator and voltage regulator are ok? The battery has a 6/2020 sticker on it so it IS 4 years old and it HAS had a problem where it keeps going dead according to the Seller I bought the car from. SO maybe we're talking about buying a battery here and seeing what happens? With the voltage going up so much while the car is running it makes me believe the alternator is working. How about you?
Go to a local auto supply store (Petboys???) with your battery. They can do a load test on it to determine if its any good. At least you'll know if the battery is the problem