Enter the resistance in ohms and capacitance in farads into the calculator to determine the total time to charge a capacitor.
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Capacitor Charge Time Formula
The following formula can be used to calculate the charge time of a capacitor.
T = R * C * 5
- Where T is the time (seconds)
- R is the resistance (ohms)
- C is the capacitance (farads)
Capacitor Charge Time Definition
A capacitor charge time is defined as the time it takes a capacitor to charge to 99%. This value is equal to 5 capacitor time constants.
Capacitor Charge Time Example
How to calculate capacitor charge time?
- First, determine the resistance.
Measure the resistance of the capacitor.
- Next, determine the capacitance.
Calculate the capacitance of the capacitor.
- Finally, calculate the charge time.
Calculate the capacitor charge time using the equation above.
A capacitor will reach a 99% charge after 5 time constants and 63.2% after just one time constant. The time constant is calculated using the formula t = R*C. Typically either 4 or 5 time constants a capacitor is considered full charge. (It will never reach 100% charge.
Conversely a capacitor will discharge only 36.8% after one time constant, but also reach near 99% discharge at around 5 time constants.