In addition to acutally driving the car, using the little features such as the lights, horn, radio, and air conditioning/heating will drain the battery of a car. Also a dead cell in the battery will cause it to run down overnight. And if something is on such as a dome light, under hood light, trunk or glove box light. A stuck relay will also run the battery down.
Sure, connect anything to the battery that will use power.
There's a parasitic drain somewhere.
A car battery in any car would drain due to a short in the electrical system.
If the ashtray light is not working it will not drain the battery.
You can get a car alarm that uses it's own battery so wont drain the car.
A starter does drain a battery. The battery holds a charge so that you can use your starter to start the car. After the car is started the alternator recharges your battery and runs your car and all it's accessories. If your car won't start or is having a hard time starting you can drain your battery by repeated unsuccessful attempts to start it.
If the alternator is installed incorrectly, yes, it can drain the battery.
Yes, if the relay was stuck it would drain the battery.
A battery charger does one thing. It charges a battery, and starts with whatever charge is in the battery and goes from there. Running an automobile battery down will shorten it's life.
No.
leaving on the radio
Yes