Oh. Okay, my 12 V car battery rated at 580 cold cranking watts is due to fry my turn signals. Good thing I never charged my phone from what used to be called the cigarette lighter port. Hate to see it after the battery pushed all them Amps into it.
The battery is able to "push" as much current into a turn signal as its resistance allows. The resistance of a turn signal lamp is much, much higher than the resistance of a starter motor. Thus the current is much much lower in the lamp than in the starter motor.
In fact, the current flows around a "circuit" from one of the battery terminals, through a switch, then to the load, through the load, and then back along another wire to the other terminal of the battery. The amount of current depends on two things: the voltage of the battery and the resistance of the load. Usually we say that the battery, which is a source of energy, "pushes" the current around the circuit.
See this explanation of a very basic electric circuit: