It's been super cold here lately. My car was starting sluggishly a few days and I had to use a jump box to start is a few days ago. Autozone said it wasn't a cold weather battery so I did a warranty swap for a cold weather battery and it started right up and I was able to do all my errands, including to get gas. So, I had a full tank and a brand new battery. Also, my oil was at proper level, according to Autozone, except he said it looked like it had water in it. They also said my alternator was good. I was driving home from my last stop and the engine stopped. Then it wouldn't start again even though it had started up really good a few times since getting the new battery. I tried jump starting it, even though the battery is brand new, just in case, but that didn't work either. Everything (dash board lights, fans, emergency flashers) acts like the battery is full except it doesn't start. All it does is a sort of clunk when you turn the key. I tried it again today (because it seems warmer even though it's still super cold) and it still just clunks. What sort of thing would make your car stop running while you're driving, but then also not let the car start back up?