What is C Rate?

C rate was developed by French Scientist & Physicist Charles Augustin de Coulomb and is derived from Coulomb's Law

 It means the rate at which a battery is getting charged or discharged.

The C rate depends on the type of battery chemistry used and also depends on the manufacturer.The higher rate of charge like 1C means the battery can be charged more quicker then 0.5C rate of charge.

The higher C rate is suitable for applications like Grid balancing,Frequency regulation,Electric Vehicles etc

For eg: 

1C - Take 10AH battery it can able to charge and discharge at the rate of 10A for 1Hr or 1A for 10Hr.
0.5C or C/2 - Same 10AH battery can able to charge and discharge at 5A for 2Hr (10/2 = 5A).
2C - Same 10AH battery can able to charge and discharge at 20A for 30min (10*2 = 20A).
5C - Same 10AH battery can able to charge and discharge at 50A for 12min (10*5 =50A).