-It doesn't solve the problem (which is why I am considering splitting them now that I have added a ~1A consumer to the mix), but it does postpone the problem for long enough to (in most cases) ensure that you will realise your mistake before it causes you not to be able to start your car.

Leaving the headlights on (~10A) as you leave the car in the evening will still let you start it in the morning, for example.