In steady state (after a long time) an ideal capacitor does not draw significant current from a battery. A real capacitor will draw some small leakage current. The amount of leakage current will depend on the type of the capacitor, electrolytics will have higher leakage than films and ceramics.
Will a capacitor keep my battery from dying?
A cap would be useless in preserving your power in the battery. You actually still have to charge it from the battery before you can use it. It will only help you avoid dimming (when you bump, your lights dim) and longer play when your car is off.
When a capacitor is connected to a battery for a long time?
When charge reaches the value Q=C*V , the electric field between the capacitor plates cancels the effect of the electric field generated by the battery, resulting in no further movement of charge. Therefore, a capacitor when connected across a battery conducts for a while and after that behaves as an open circuit.
How do you tell if its your battery or alternator?
An illuminated dashboard light can indicate a problem with an automobile charging system. However, a very simple way to check if the alternator is working is to run the car and disconnect the positive terminal of the battery. If the vehicle stops running, then you probably have a bad alternator.
When a parallel plate capacitor is connected?
The quantities charge, voltage, electric field and energy associated with the capacitor are given by Q0,V0,E0 and U0 respectively. A dielectric slab is introduced between plates of capacitor but battery is still in connection.
What does the capacity of a capacitor depend on?
The capacitance of a capacitor is affected by the area of the plates, the distance between the plates, and the ability of the dielectric to support electrostatic forces.