The formula to calculate the C rate of a battery is:
\[ Cr = \frac{I}{E} \]
where \( Cr \) is the C rate, \( I \) is the current of charge/discharge (Amps), and \( E \) is the rated energy of the battery (Ah).
C-Rate is defined as the inverse of the time it takes, in hours, to charge or discharge a battery. For example, a battery that takes 2 hours to charge has a C Rate of \( \frac{1}{2} = 0.5 \).
Let's assume we have the following values:
Step 1: Divide the current of charge/discharge by the rated energy:
\[ Cr = \frac{10}{20} = 0.5 \]
Therefore, the C rate is \( Cr = 0.5 \).