You seem to have some basic misconceptions about capacitors. The current thru a capacitor is proportional to the change in the voltage. In more mathematical terms:
current = K dV/dt
The proportionality constant K is the capacitance. When the units are Amperes, Volts, Farads, and seconds, it all works out with a scale factor of 1:
Amps = Farads * Volts / second
So if nothing is externally forcing the voltage of a capacitor to change, there will be no current thru it. Equivalently, if nothing is forcing current thru a capacitor, it's voltage won't change. If you charge up a capacitor to 9 V by connecting it accross a 9 V battery and waiting long enough for the current to go to zero (the voltage to stop changing), then disconnect it, the voltage on the capacitor will stay 9 V. That is for a perfect capacitor. Real capacitors have leakage, meaning a little current will leak thru them to discharge them, as if a large resistor was connected accross them.
The voltage rating of a capacitor only tells you how many volts you can charge it up to before it may break. So charging up a 16 V capacitor to 9 V is perfectly fine since 9 V is less than 16 V, but that 16 V rating has otherwise nothing to do with how many volts will be on the capacitor in a circuit.