Bad Battery and other problems

Hello all. I wrote a week ago about my cruise control going out and then a delay between turning the key and the engine starting. Yesterday, my car would not start and the battery was completely dead. I had the dealership take it in and swap the battery under warranty. I got my car back later that day and everything was working fine again! I have researched all I can, but cannot find anything. Can a bad battery really cause the cruise control to stop working? Does this sound like the end of it, or should I get the electrical system checked out? Thanks!

Low voltage in a circuit can cause all sorts of weird thing to happen. If the cruise works now I'd say that was the cause.