RC Time Equation?

Question

IS there any way to redo the RC time equation for a given voltage, rat,her than a given resistance? like if you, say, doubled the voltage, the cap would charge twice as fast, but what's the equation?

Answer 1

Vc=q(t)/c

where Vc = voltage across the cap
q = total charge
t = time
c = capacitance in farads

Increase voltage, increases charge time.

Answer 2

The time equation is independent of voltage because of the voltage-current relationship provided by resistance. If you double the voltage, the current will double as well, putting the same amount of charge on the plates in half the time, but requiring twice the charge to reach the same voltage on the capacitor.
If you wanted, you could write the capacitor time constant as tau=I/(V)(C) .