More Issues With New Edge

Alright so the sensor cane in today and I got it put in and so far the problem is fixed (again)

When i took the old sensor out, the metal part on the back which I'm assuming is where the contact for the connector hits was covered in what looked like a thick carbon buildup. The new one was nice and clean and shiny so I'm hoping that I don't ha e to deal with this anymore

Welp. Everything was fine on the test drive and on the way to work. On the way back it died coming up to a light and then a few minutes later it did the jerking thing. Hasn't died idling yet tho. Pulled over and disconnected the battery and put the terminal together to drain residual power and it was fine after that.

Battery is 12-12.4 with engine off and on its a steady 14.4.

A bad Battery wouldn't make this happen would it? It is worth noting when I first installed the alternator the engine seemed to run smoother and quiter and there was no more alternator whine. Now it runs like it did when I first started having the issues and there's alternator whine.

The battery is labeled as 04/23 so it's two years old. Guy i bought it from said he had to charge the battery a couple days before I bought
Before I go out and spend $130 on a new battery is it a possibility that it's the battery causing this?

Took the battery to Autozone and they said that the battery is good. Looked like all he did was hook up a multimeter with a screen and checked voltage. Didn't appear to run any load test on it so who knows.

I did test the alternator for AC ripple voltage and it was reading 30-31.5 (volts? Amps?) And it should read .1-.2 if the alternator is good. So I'm not sure if the battery caused the alternator to fail or if this alternator was junk on delivery. I guess I'm gonna have to hook up a battery charger snd see if that helps cause then that would mean it's the battery