KV or kV? - what does it all mean?

KV, or Kilovolt, is a measurement used to describe the speed of a brushless Direct Current (BLDC) motor. It represents the number of revolutions per minute (RPM) that a motor will rotate at when a voltage of 1 kilovolt (1,000 volts) is applied to it with no load. This measurement is important because it helps to determine the most efficient operating range for a given motor and power source.

A BLDC motor is a type of electric motor that uses electronic commutation, instead of brushes, to switch the current in the windings. This allows for more efficient operation and a longer lifespan compared to traditional brushed DC motors. Because BLDC motors are typically more efficient and have a longer lifespan, they are often used in electric vehicles, drones, and other high-performance applications.

The KV value of a brushless motor can be used to calculate the RPM of the motor at a given voltage. For example, if a motor has a KV of 1000, it will rotate at 1000 RPM when 1 volt is applied to it with no load. This means that if you are using a 4S LiPo battery (14.8V) the motor will rotate at 14,800 RPM.

When choosing a brushless motor, it's important to consider the KV rating in conjunction with other factors such as the motor's torque, current draw, and power output. This will help to ensure that you select a motor that is well-suited for your application and will operate efficiently.

Well, that's one school of thought.. the other is that kV actually means Constant Velocity (where lower case k is the mathematical symbol for a mathematical constant)... but ultimately the calculation of no. of volts in your battery, multiplied by the kV rating, gives you revolutions per minute.

In summary, KV is a measure of the speed of a brushless motor which helps to determine the most efficient operating range for a given motor and power source. It also can be used to calculate the RPM of the motor at a given voltage.