I have a 08 Chevy Impala LTZ, have been having problems with my battery draining. This especially happens when it is cold out. My battery is fine and so is the alternator. How can I tell if this is a problem with the battery cables without having to take it to the dealership?

Try cleaning and tightening all battery cables also do the negative cables to the frame and motor. How old is your battery? If over five years it may not have the CCA needed to start your vehicle on cold mornings. All because a battery has 12.5 volts or more does not necessarily mean that it's still at its peak performance.

My battery is about a month old, I will have my brother in law try your suggestions before I do anything else. Thank you.

Ok. If all that checks out ok then have your starter tested. Is battery actually going dead and you have to recharge it or just hard to start in cold but acts normal during the day? If it's going dead you might have a parasitic draw issue.

www.youtube.com/watch?v=KF1gijj03_0 -- if battery going dead here's a video on how to perform a parasitic draw test.

I had this problem last winter and as soon as it started getting warm, the problem went away, now that its 22 degrees out the last few days, I've had the problem again. I had a couple different new batteries.

Ok might be a starter issue. Sometimes when they start to go bad you notice it mostly on cold mornings. Might want to check the connections on the starter. Dirty or loose connection there might also cause this kind of issue.

thank you for the suggestions, I appreciate it

Similar problem with friends daughters car. 2008 Impala with <70k miles. Pristine car. Even with a brand new battery, car would be dead if it sat unused for 3 days. Found the car had a ~0.533 amp parasitic draw. Found ~0.365 was being drawn through the OnStar fuse at all times. We left that fuse out. The remaining ~0.160 cleared when the Fan #2 relay was pulled. It could not be duplicated, even after reinstalling the relay. Now, when battery is connected, car goes through a normal routine where current draws up to 2.5 amps initially, then eases down in a few steps over about a minute and settles at 10 ma. 1/50th of what it was previously. I suspect the battery wont be draining any longer.