[BrianG]

Incidentally, the formulas for finding capacitor voltage at any time (not just during the 1,2,3,4, or 5 time constants) are:

Charge:
capacitor_v = v_battery X (1 - 2.7182^(-t / (R X C)))

Discharge:
capacitor_v = v_battery X 2.7182^(-t / (R X C))

capacitor_v = capacitor voltage at "t" seconds
v_battery = battery voltage
2.7182 = Euler's constant
t = time in seconds
C = capacitance in farads
R = Resistance in ohms