In the UAV system, batteries (energy supply) and motors (power output) constitute the core power chain. They do not operate independently, but are deeply coupled and mutually restricted, jointly determining the performance limit, endurance and flight safety of the UAV. Understanding the matching logic between the two is crucial for selection, integration and optimization.
How motor parameters drive battery selection
The key electrical characteristics of the motor directly determine the configuration specifications of the required battery:
Voltage: The "language" of the motor, the battery must "understand"
Core requirements: The total output voltage of the battery pack must strictly match the rated operating voltage of the motor (such as 12V/3S, 22.2V/6S, 44.4V/12S).
Mismatch consequences:
Insufficient voltage → The motor cannot start or the performance is seriously degraded.
Too high voltage → The motor coil is likely to burn out.
Example: A motor rated at 44.4V must be paired with a 12S lithium battery pack (12 * 3.7V ≈ 44.4V).
Current: To satisfy the motor's "appetite", the battery must have sufficient "explosive power"
Core requirement: The maximum continuous discharge capacity of the battery pack (i.e. discharge rate (C-rate) * capacity (Ah) = maximum current (A)) must cover the peak current demand generated by the motor at maximum load (such as rapid acceleration, climbing, wind resistance).
Consequences of failure to meet:
Insufficient battery current → drastic drop in output voltage (voltage sag) → insufficient motor thrust momentarily, which may lead to loss of control.
The battery is over-demanded → severe heating, bulging, and even thermal runaway.
Design criteria: The maximum discharge current of the battery should at least meet the peak current demand of the motor, and it is strongly recommended to reserve more than 20% margin to ensure safety and battery life.
Improved motor efficiency → Reduced power consumption under the same load → Smaller capacity and lighter batteries can be used to achieve the same driving range → Improved overall system energy efficiency.
Battery specifications negatively restrict motor performance
1. Battery voltage determines motor speed output
The motor speed formula is: speed = KV value × voltage.
KV value is the characteristic constant of the motor, and the input voltage is determined by the battery. If the voltage is too low, the motor will be underpowered, and if it is too high, the motor may be overloaded, damaging the winding or affecting the stability of the ESC.
2. Battery discharge capacity limits motor thrust release
Even if the motor itself has high thrust potential, if the battery cannot continuously provide the required current, the motor will be "underpowered" and the performance will be discounted. For example: if the battery can only provide 300W power for a motor with a maximum power of 500W, the thrust will drop significantly and even affect flight stability.
3. Battery weight affects motor thrust configuration
The larger the capacity of the battery, the more power it provides, but the heavier it is. If the motor thrust is not enough to support the heavier battery, the flight performance will be reduced and the flight time will be shortened. Therefore, a reasonable balance needs to be found between battery capacity and motor thrust.
Matching logic and design recommendations for motors and batteries
In order to achieve optimal flight performance, system-level matching should be performed according to the following logic:
Clear mission requirements: determine flight time, load, working environment and other goals.
Select a suitable motor and propeller combination: determine the motor KV value, maximum current, recommended voltage, etc. according to the load and thrust-to-weight ratio requirements.
Match battery specifications: According to motor parameters, select batteries with matching voltage, appropriate discharge rate, and capacity that meets the endurance target.
Evaluate overall energy efficiency ratio and weight: Comprehensively consider battery weight, motor thrust, and ESC specifications to avoid performance bottlenecks.
Reserve safety margin: It is recommended that battery discharge capacity ≥ actual current × 1.2; motor thrust ≥ flight total weight × 2 to 2.5 times.
To meet the higher performance requirements of drones, motor and battery technologies are moving towards:
Evolution of high-voltage systems (18S/20S) → Reduce losses and improve energy efficiency.
Popularization of smart batteries → Real-time monitoring to ensure safety.
Electric control motor integration development → Lightweight, fast response, simplified system.
Breakthrough in new materials and thermal management → Pursuit of higher energy density and heat dissipation capabilities to enable high-power flight.
As a manufacturer specializing in lithium polymer batteries, LYW focuses on innovation and continuously brings customers affordable high-quality batteries. Its products are widely used in various scenarios and have received unanimous praise from customers. If you have any needs, you can contact the online customer service or call us, we will provide you with the best service
