Demand for fast charging is growing so fast that there are even fast chargers and fast-charging cables. If you are interested in the speed of charging and discharge of batteries, there is a term you need to know: C-rate (Current rate).
What is C-rate
Abbreviated from “Current rate,” the C-rate is a measure of the rate at which a battery is charged or discharged relative to its capacity. It is also called “charge and discharge rates” and the unit is C that represents for capacity. It can be calculated by dividing the charging or discharging current (A) by the rated battery capacity (Ah) as below. The capacity of a battery is generally rated at 1C.
The Use of C-rate
What does it mean to know a C-rate in using battery?
First, charge C-rates help users estimate how long it will take to fully charge their batteries. For example, when you see a battery label that says “Chargeable at 10C” means the battery can be charged at the current of 10 times of the battery capacity and it takes at least 6 minutes to be completely charged.
Second, discharge C-rates help users expect the limits of product performance. For example, drones require lightweight and small batteries in order to fly. A battery with a low discharge C-rate may not be able to offer high enough current needed for doing some tricks. But a high C-rate battery discharges faster and eliminates such worries.
Let’s suppose that there is a drone battery with a discharging rate of 100C. The battery can supply current of up to 100 times of its capacity, but if the drone continues the move that requires that much power, it is discharged 100 times faster than the standard of an hour (3,600 seconds). Accordingly, it is discharged in just 36 seconds.
Check C-rate When Buying Electronic Devices Running on Battery
As we use more batteries in our daily lives, more devices demand fast charging or a sudden rush of high current. Hopefully, the C-rate we have discussed today will come handy when you purchase electronic devices with batteries that best fit your purpose. Remember the C-rate and check the charging and discharging rates!