Car dies if I’m not giving it gas...

RustyRatRod said

If you don't have a charging system tester, go to your local auto parts store and get your alternator tested.

Click to expand...

Even just a basic simple volt meter connected to the battery will tell, if the person doesn't know what a loaded alternator sounds like.
It is nice to have actual numbers though, and a basic volt/ohm meter is a nice tool to have.