How are you doing? The battery indicator illuminating on your dashboard means there is a charging issue; however, it does not necessarily mean that your battery is about to die. There are many reasons why it could come on, including: Loose battery cables. Corroded battery cables or terminals. Since Pep boys checked the alternator, part of the charging system like a computer malfunction or ECU can be at fault.
We should consider the sensors as well. There are several sensors placed around the battery, as well as the alternator. When the sensors are not working correctly, the charging system malfunction light will turn on without the sensors, and the computer inside the engine will not know if all the components are performing correctly.
If a sensor has gone bad, then you will need to find that sensor and replace it. There are multiple sensors around the engine and around the charging system and battery. You’ll need to test each sensor to see which one is no longer working.
Hope this helps and I will try to call you.