I've noticed that my car will not crank if I have my lights on or any accessories on for a short time without the engine running. I first noticed this when I had my headlights replaced. It only took 45min-hour to put in. And the installer turned them on before and after to check them out. And had the door open a few times. Can't remember if the key was on though. But, after that my car would not start at all. The second time was when I was in the car with the radio on. Engine off. Radio was not up too loud. And it was only on for about 15 minutes. Again, it wouldn't start. I had the battery checked and it was good. One mechanic told me it was normal, because these cars have so many electronics in them. Is that true? I only get 15 minutes of battery life before I need a jump?? If so, should I consider a deep cycle battery?

First thing I would do is check the voltagewith the ignition off. 12.6v is a healthy battery. If that checks out, Have it load tested in the car. If it doesn't pass the load test in the car, but it did outside of the car, your terminals are probably dirty.