Scotty My 2012 Hyundai Accent 1.6 won’t start in the cold. It won’t even turn over. I tried replacing the battery but that didn’t work. The car starts up almost immediately in warmer temperatures. What can cause this?
First of all, check to see if there's any corrosion on the clamps or posts of the battery. If there is, then clean these off, with a battery wire brush (cheap). Make sure that the clamps are on tight, and there are no frayed wires coming out of the battery clamp harness.
Secondly, test the alternator. Perhaps the alternator is not sufficiently charging the battery (text and video instructions for testing the alternator are easily found via a Google search).
Third, since this is a de facto electrical issue, there could be an intermittent short in the wiring between the ignition switch and the battery. Those need to be tested for power and ground.
There are other issues, possible, as well, such as a fuel pump going bad.
Specifics related to the Accent are discussed, here:
https://www.700r4transmissionhq.com/Hyundai-Accent-wont-start/
And there's a link to a Diagnostic Flow Chart, on the "Accent Won't Start" page (below).
I would put a battery with higher CCA.
get the highest CCA battery that will fit in the battery box