A Comprehensive Guide to Understanding Key Parameters of Drone Batteries

What are the key parameters of drone batteries? What do they represent? How are they interrelated? And how do they affect the performance of drone equipment?

Drone Battery

ENOV High-Energy drone batteries power industrial and commercial drones. Delivering 220–320 Wh/kg energy density, they enable long flight times (30+ mins) and support fast charging (2C). Perfect for aerial photography, surveillance, and delivery drones.

1. Voltage and Cell Series (Unit: V, usually marked as "X S", 1S = 3.7V)

Voltage determines the power output of the battery and is a key factor affecting motor speed and the overall performance of the drone. The nominal voltage of a single battery cell is typically 3.7V, and the full-charge voltage is 4.2V. The number of cell series refers to the quantity of battery cells connected in series, which determines the total voltage of the battery; the more cells in series, the higher the battery voltage.

Voltage calculation rules:

Nominal voltage = Number of series (S) × 3.7V (nominal voltage of a single battery cell)

Full-charge voltage = Number of series (S) × 4.2V (full-charge voltage of a single battery cell)

For example, a battery with 6 cells in series has a total nominal voltage of 6 × 3.7 = 22.2V.

✈️ Relationship with drones: Voltage is equivalent to the “engine horsepower” of a car. The higher the horsepower, the stronger the power base of the car (e.g., it can pull heavier loads). Similarly, the higher the voltage of the drone, the higher its “power ceiling”, enabling it to carry heavier loads such as cameras and sensors; higher voltage also allows the motor to rotate faster, resulting in stronger flight speed or climbing speed. However, the voltage must match the drone’s motor and electronic speed controller (“power controller”); otherwise, the equipment may be burned out. For instance, a drone designed for a 3S battery cannot use a 6S battery, which is like installing a high-horsepower power system on a low-horsepower engine, leading to overload.

Table of Drone Battery Specifications and Applicable Types

Number of series (S)	Nominal voltage (V)	Full charge voltage (V)	Applicable drone types
1S	3.7V	4.2V	Micro drones (such as Toy-level, indoor aircraft)
2S	7.4V	8.4V	Small entry-level drones (such as DJI Tello, FPV practice machines)
3S	11.1V	12.6V	Medium racing drones, aerial photography drones (such as 5-inch FPV models)
4S	14.8V	16.8V	High-performance FPV racing machines, medium commercial drones
6S	22.2V	25.2V	Professional aerial photography drones (such as DJI Mavic 3), industrial drones
8S +	≥29.6V	≥33.6V	Large industrial drones (such as plant protection drones, freight drones)

2. Capacity (Unit: mAh or Ah, 1Ah = 1000mAh)

Capacity refers to the amount of energy stored in the battery, representing the electric current that the battery can output over a period of time, and is an indicator of the battery’s energy storage capacity.

✈️ Relationship with drones: The battery capacity is equivalent to the size of a car’s fuel tank. A larger fuel tank can hold more fuel, allowing the car to travel farther. Similarly, a larger capacity of the drone battery results in a longer flight time of the drone (provided other parameters match). For example, a 2000mAh battery may enable 5-10 minutes more flight time than a 1500mAh one (depending on the drone’s power consumption).

3. Discharge Rate (Unit: C, e.g., 10C, 20C)

The discharge rate refers to the ability of the battery to release electricity instantaneously in a safe state. Calculation formula: Maximum discharge current = Capacity (Ah) × C rating. For example, a 1000mAh (1Ah) battery with a 10C rating can release a maximum current of 10A.

✈️ Relationship with drones: The discharge rate is equivalent to the “acceleration capability” of a car. For example, sports cars accelerate faster than family cars. Similarly, it indicates the acceleration ability of the drone; a higher discharge rate allows the drone to burst out greater power instantaneously.

When a drone takes off, accelerates rapidly, or hovers (to counter wind resistance), it requires an instantaneous large current. If the C rating is insufficient, it will lead to “insufficient power” (e.g., difficulty in taking off, loss of altitude).

Batteries with a high C rating are suitable for scenarios requiring “strong maneuverability” (such as racing drones and load-carrying flights), but an excessively high C rating will consume more power (just like sports cars accelerate quickly but consume more fuel).

4. Charging Rate (Unit: C, e.g., 1C, 2C)

The charging rate refers to the charging speed of the battery. 1C means the battery can be fully charged within 1 hour. For example, a 2000mAh battery with a charging rate of 1C can be fully charged in 1 hour; with a charging rate of 2C, it can be fully charged in half an hour. The higher the charging rate, the shorter the time required to fully charge the battery. However, it should be noted that not all batteries can withstand high charging rates, which is related to factors such as the quality of the battery cells and internal resistance. Blindly using a high charging rate may damage the battery and shorten its cycle life, so please follow the manufacturer’s recommended charging rate.

The charging rate is equivalent to the “refueling speed” of a car. For example, a fuel gun at an ordinary gas station can add 10 liters of fuel per minute, while a fuel gun at a fast gas station can add 20 liters per minute. Obviously, the latter can fill the car’s tank faster, but if the fuel tank or refueling system does not support it, problems such as oil leakage may occur when refueling the car’s tank quickly.

✈️ Relationship with drones: A higher charging rate means a shorter charging time, reducing the waiting time for the drone and allowing it to be put into use faster.

5. Internal Resistance (Unit: mΩ)

Internal resistance refers to the resistance encountered by the current when flowing inside the battery.

✈️ Relationship with drones: Internal resistance is equivalent to the “thickness of the oil pipe” from the car’s fuel tank to the engine. The thinner the oil pipe, the greater the resistance to oil flow, and the less smoothly the engine receives oil. Similarly, the smaller the internal resistance of the drone battery, the more smoothly the battery outputs current, enabling it to supply power to the drone more efficiently. For example, a battery with small internal resistance can stably output current when the drone is flying under high load, avoiding situations where the power fluctuates; while a battery with large internal resistance, like a thin oil pipe, has low power supply efficiency and may generate severe heat when outputting large currents, affecting the battery life and the flight safety of the drone.

6. Cycle Life

Cycle life refers to the number of charge-discharge cycles after which the battery performance significantly degrades (usually when the capacity drops to 80% of the initial value). This is equivalent to the “service life of the car’s fuel tank”. For example, a fuel tank will rust and its capacity will decrease over time (e.g., originally 50L, but later only 40L can be held). The longer the cycle life of the battery, the longer it can be used, reducing replacement costs; it should be noted that overcharging and over-discharging (complete depletion of power) of the battery will shorten its service life.

7. Connector

The connector is the interface used to connect the battery to the drone equipment or the battery to the charger. There are various types of connectors, and drones of different brands and models are usually equipped with specific types of connectors.

✈️ Relationship with drones: The connector is equivalent to the “refueling interface” of a car. Different car models have different refueling interfaces, and if the interface is incorrect, fuel cannot be added. Similarly, if the connector does not match, the battery cannot supply power to the drone, just like using a car’s fuel gun to refuel a truck, which simply cannot be plugged in. Therefore, the type of battery connector must be compatible with the drone’s power system. Common types of drone connectors include XT60, XT90, T-connector, etc. (for details, please refer to my other article, The eight most common drone connector types). When you purchase a battery, please make sure that the connector matches the drone.

8. Weight

The weight of the battery is equivalent to the weight of the car’s fuel tank itself. For example, a 50L fuel tank made of iron is heavier than one made of aluminum alloy. Similarly, under the same capacity, lithium polymer drone batteries are lighter than lithium-ion drone batteries, and lithium-ion drone batteries are lighter than lead-acid and nickel-metal hydride batteries.

✈️ Relationship with drones: The battery weight is one of the main loads of the drone, occupying the effective payload of the drone, and the drone has a “maximum load limit”. Therefore, the battery weight must be within this range; otherwise, the drone cannot take off or is prone to losing control. Batteries with large capacities are usually heavier (because more cells are needed), but excessive weight will offset the advantage of the duration of flight brought by large capacity. For example, a racing drone carrying a heavy battery will fly more strenuously and consume power faster.

9. Size

The size of the battery refers to the length, width, and height of the battery casing.

✈️ Relationship with drones: The size of the battery is equivalent to the “external size” of the car’s fuel tank. If the shape and size of the fuel tank do not match the reserved installation space of the car, it cannot be installed. Similarly, the size of the drone battery must fit the battery compartment of the drone’s fuselage. If the size is too large, the battery cannot be placed into the battery compartment; if the size is too small, the battery will shake in the battery compartment, which may cause poor contact, affect the stability of the power supply, and even fall off during flight, resulting in the drone losing control.