What is C Rating for Battery

The “C” in C rating doesn’t stand for capacity; it stands for “Capacity multiplier”.

A battery’s “C rating” is a measure of its discharge rate, which indicates how quickly a battery can release its entire charge. The C rating is a critical factor in the performance of batteries, especially in applications where high power output is required over a short period, such as with radio-controlled (R/C) models, drones, or high-performance electric vehicles.

The C rating is multiplied by the battery’s capacity to determine its maximum continuous discharge current. A battery’s capacity is usually given in milliampere-hours (mAh) or ampere-hours (Ah).

Here’s how it works:

For example, if a battery has a capacity of 1000mAh (or 1Ah) and a C rating of 20C, the maximum continuous discharge current you can draw from it would be:

20C x 1Ah = 20A

This means the battery can be safely discharged at a continuous current of 20 amps without damaging the battery or reducing its lifespan significantly.

If a battery has a higher C rating, it can release its stored energy more quickly, which is essential for devices that require a lot of power in a short time. However, it’s important to note that while a higher C rating allows for a higher discharge rate, it may not always be beneficial to use the maximum discharge rate as it can lead to increased heat, which could potentially harm the battery or reduce its longevity. Always refer to the manufacturer’s guidelines to ensure you’re using the battery within its safe operational limits.

The C rating refers to the rate at which a battery can be discharged relative to its maximum capacity. It’s a multiplier that tells you how fast the battery can be safely discharged without causing damage or reducing its lifespan significantly.

To give you an example:

  • If you have a 1000mAh battery with a 1C rating, it means the battery can be discharged at 1 ampere (1000 milliamperes) for one hour before it is fully discharged.
  • If the same 1000mAh battery has a 2C rating, it can be discharged at 2 amperes for half an hour.
  • If it has a 20C rating, it can be discharged at 20 amperes for 1/20th of an hour (or 3 minutes).

The capacity of the battery, on the other hand, is a measure of how much charge it can hold, usually expressed in milliampere-hours (mAh) or ampere-hours (Ah). It’s a separate characteristic from the C rating, but they are related in the sense that you use the capacity (Ah) along with the C rating to determine the maximum safe continuous discharge rate of the battery in amperes (A).