The relationship between a higher Kv motor and battery power is a complex one that requires a deeper understanding of both battery and motor specifications. In this article, we’ll explain why the answer to the question is both “yes” and “no” and what factors contribute to this answer.
Table of Contents
Battery Specifications
When it comes to batteries, the two key specifications to consider are voltage and capacity, measured in milliamp-hours. The higher the voltage, the more power the battery can deliver, while the capacity determines how long the battery can deliver that power.
Motor Specifications
For motors, the two key specifications to consider are Kv and physical size. Kv, or the velocity constant, determines the RPM that the motor will produce for every volt it receives. The physical size of the motor affects the amount of power that can be drawn from the motor. In order to compare motors accurately, it’s important to consider only motors of the same physical size.
Example 1
Consider the following example: we have a 6s 4,000 milliamp-hour battery pack and two motors, a 1500 Kv and a 1200 Kv motor, both 40 by 68 millimeters in size. The 1500 Kv motor operates at a total RPM of 33,000, while the 1200 Kv motor operates at 22,200 RPM.
As we can see, the 1500 Kv motor is spinning up to a significantly higher RPM than the 1200 Kv motor. As a result, it requires more power to hit that RPM, drawing more current from the battery. In this example, the answer to the question “does a higher Kv motor use more battery power” is a definite “yes.”
Benefits and Limitations
While a higher Kv motor does draw more power from the battery, there are some benefits to this setup. The increased power draw should result in more work being done, allowing for faster movement or the ability to move larger vehicles. However, there are also some limitations to consider. The motor must be able to handle the increased current and RPM, and the speed control and batteries must be capable of delivering the necessary power.
Example 2
In a second example, we have a 4s 4,000 milliamp-hour battery pack and a 4s 6,000 milliamp-hour battery pack, both with a c-rating of 45C. We’ll use the same 1500 Kv and 1200 Kv motors as in the first example.
In this scenario, the 1500 Kv motor still requires more power to hit its higher RPM, but the 6,000 milliamp-hour battery pack is able to deliver that power for a longer period of time. The answer to the question “does a higher Kv motor use more battery power” is “no” in this example, as the higher capacity battery can deliver the necessary power for a longer period of time.
In conclusion, the relationship between a higher Kv motor and battery power is not a simple one, and the answer depends on multiple factors. However, with a deeper understanding of battery and motor specifications, it’s possible to determine the best setup for your specific needs.