Soft-pack Lithium Batteries for Drones

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.

Soft-pack lithium batteries for drones, which use aluminum-plastic composite film as the packaging material, fall under the category of lithium-polymer batteries. Boasting advantages such as lightweight design and high energy density, they have become the primary power source for lightweight drones (including consumer-grade and industrial-grade models) and play a crucial role in various fields such as agriculture, surveying and mapping, and security. The following is a detailed analysis of these batteries from multiple dimensions.

I. Core Characteristics

(I) Advantages

• High Energy Density: Most of these batteries adopt lithium-polymer cells, and some models combine advanced materials such as high-nickel nickel-manganese-cobalt (NMC) cathodes and silicon-carbon anodes. Their energy density can reach over 200Wh/kg, and some semi-solid-state batteries can even exceed 300Wh/kg. This significantly extends the flight endurance of drones, enabling long-duration operations.

• Lightweight Design: Compared with traditional metal casings, aluminum-plastic film packaging reduces weight by 10%-20%. This effectively lowers the overall weight of the drone, enhances flight efficiency and maneuverability, and meets the weight-sensitive design requirements of drones.

• Flexible Shape Customization: Without the constraint of rigid casings, these batteries can be customized into various shapes, such as flat and curved ones, according to the internal structure of the drone. This allows them to fit closely to the drone body, greatly improving space utilization and adapting to the design differences of different drone models.

• Excellent Charging and Discharging Performance: They support high-rate discharging, with a common discharge rate ranging from 5C to 30C. Some batteries specifically designed for racing drones can even achieve a discharge rate of 100C, which meets the instantaneous high-power demands of drones during takeoff, climbing, and high-speed maneuvering. Meanwhile, some models support 2C-5C fast charging, and products from certain brands can be charged to 80% capacity in 30 minutes, shortening the interval between operations and improving work efficiency.

• Unique Safety Features: Under extreme conditions such as overcharging and over-discharging, the aluminum-plastic film usually bulges to release internal pressure instead of directly exploding, and the risk of liquid leakage is relatively low (the aluminum foil layer can effectively block the electrolyte). However, precautions should be taken to prevent puncture damage.

• Strong Wide-Temperature Adaptability: Most products have an operating temperature range of -20℃ to 60℃, enabling them to maintain stable power output in harsh environments such as cold fields and high-temperature deserts, thus adapting to operational needs in different regions and seasons.

• Cost and Process Advantages: The production process does not require complex hard-shell processing procedures, resulting in low resource consumption. The manufacturing cost of conventional models is relatively low, providing certain cost-effectiveness.

(II) Disadvantages and Risks

• Weak Mechanical Strength: The aluminum-plastic film casing has poor impact and puncture resistance, and is prone to damage from extrusion and collision. Additional protective casings or buffer layers need to be designed, which increases the design cost and volume on the application side.

• Limited Cycle Life: The cycle life of conventional products is generally 300-500 cycles, and some optimized products can reach 650-750 cycles (the cycle count of Enovbattery is approximately 800 cycles). Regular replacement is required after a period of use, increasing the long-term usage cost.

• Risk of Swelling: Factors such as overcharging, over-discharging, high temperature, or aging may cause the battery to bulge, affecting performance and even posing safety hazards. A high-precision Battery Management System (BMS) is required for monitoring.

• High Customization Cost: Non-standard models need to be customized according to the specific requirements of the drone, resulting in low standardization. Only a few manufacturers provide customization services, and the customization process is costly, making mass production difficult.

• Difficulty in Consistency Control: Flexible packaging has high requirements for production precision, and the performance of individual cells is prone to differences due to process influences. Strict screening of cells is necessary during battery assembly to ensure stable overall performance.

II. Key Technical Parameters

• Voltage: The nominal voltage of a single cell is usually 3.7V, and the full-charge voltage is 4.2V. In practical applications, multiple cells are often connected in series, with common combinations including 3S (11.1V), 4S (14.8V), 6S (22.2V), and 12S (44.4V). The voltage must match that of the drone’s motor and electronic equipment to avoid damaging the equipment.

• Capacity: The common capacity range is 1000mAh-30000mAh, and some industrial-grade products can have higher capacities. Generally, a larger capacity means a longer theoretical flight time, but the battery weight will also increase accordingly. A balanced selection should be made based on the drone’s size, power consumption, and operational requirements.

• Discharge Rate (C-Rate): It represents the discharge speed of the battery, which is a multiple of the rated capacity. For example, 10C means a current 10 times the capacity (a 5000mAh battery with a 10C discharge rate has a discharge current of 50A). Racing drones require a high discharge rate (usually higher than 45C), while aerial photography and surveying drones can use a moderate discharge rate.

• Temperature Range: The operating temperature is generally -20℃-60℃, and the charging temperature should be controlled within 0℃-45℃. Using the battery beyond this range will affect its performance and service life, and even pose safety risks.

• Size and Weight: The battery must fit the installation space of the drone, and its weight should be controlled within a reasonable range, usually less than 20%-25% of the drone’s takeoff weight, to avoid excessive weight affecting flight efficiency and controllability.

• Connector Type: It must match the drone system to ensure stable power transmission and avoid power supply interruption or performance fluctuation caused by connection issues.

III. Typical Application Scenarios

• Consumer-Grade Drones: For example, most models of Enovbattery adopt soft-pack batteries. With their lightweight design and moderate endurance, they meet the needs of personal aerial photography and entertainment.

• Agricultural Plant Protection Drones: High-capacity and high-voltage models are commonly used, which can support long-duration and high-load crop spraying and field monitoring operations.

• Surveying, Mapping, and Inspection Drones: High-voltage and long-endurance soft-pack batteries are mostly selected to provide stable power for high-precision and long-duration tasks such as topographic surveying, power inspection, and bridge detection.

• Racing Drones: They are equipped with soft-pack batteries with a high discharge rate to meet the instantaneous high-power demands of high-speed flight and rapid maneuvering, ensuring performance during competitions.

• Emergency Rescue and Logistics Drones: In emergency rescue scenarios, batteries need to be deployed quickly and provide reliable power supply. Logistics drones have requirements for endurance and load capacity. The fast-charging feature and high energy density of soft-pack batteries can meet these needs and improve task efficiency.

IV. Usage and Maintenance Guidelines

(I) Charging Specifications

• Use a dedicated balance charger and avoid using incompatible chargers. The charging current should generally not exceed 1C (unless the battery is marked as supporting fast charging). For a 5000mAh battery, the charging current is recommended to be set at 5A or lower.

• When charging, place the battery in a fireproof bag or a safe area, keep it away from flammable materials, and do not place it alone. Someone should be on-site to monitor the charging process.

• If the battery temperature is too high after flight, allow it to cool down to room temperature before charging to avoid damage caused by charging a hot battery. If the battery is found to be swollen or leaking during charging, stop charging immediately.

(II) Storage Requirements

• When not in use for a long time, discharge the battery to 3.8-3.9V per cell (with an overall charge level of approximately 40%-60%) and avoid storing it in a fully charged or low-charged state.

• Store the battery in a cool and dry place, with the temperature controlled between 0℃ and 25℃. Avoid direct sunlight, high-temperature, or humid environments. Regularly check the battery status during storage to prevent swelling and damage.

• A fireproof bag should also be used during storage to ensure safety and reduce the risk of accidents.

(III) Daily Inspection and Maintenance

• Before each flight, inspect the battery’s appearance to check for swelling, leakage, cracks, or physical deformation. If any problems are found, stop using the battery and replace it immediately.

• Regularly clean the battery’s electrode tabs to prevent rust from affecting electrical conductivity. Calibrate the battery regularly according to the drone manual to ensure accurate power display.

• Allow the battery to rest and cool down sufficiently between two flights to avoid overheating and aging of the battery due to continuous high-intensity use.

(IV) Scrap Standards and Disposal

• When the battery capacity decays to less than 80% of its initial capacity, or if obvious swelling, leakage, or inability to charge occurs, the battery should be stopped from use and scrapped.

• Scrap batteries should not be discarded randomly. They must be sent to professional recycling centers and disposed of in accordance with environmental protection requirements to avoid environmental pollution or safety hazards.

V. Comparison with Other Battery Types (Taking Cylindrical Batteries as an Example)

Comparison Dimension	Soft-Pack Lithium Batteries for Drones	Cylindrical Batteries
Weight and Volume	Lightweight, flexible in volume, and high in space utilization	Relatively heavy, fixed in volume, and poor in space adaptability
Energy Density	High (over 200Wh/kg, some exceeding 600Wh/kg)	Relatively low, with conventional models below 200Wh/kg
Discharge Performance	Supports high-rate discharge (5C-100C), suitable for high-power demands	Low discharge rate, mostly 1C-5C, difficult to meet instantaneous high-power demands
Safety	Bulges to release pressure under extreme conditions, low risk of liquid leakage, but weak impact resistance	Metal casing provides strong impact resistance, but a relatively higher risk of explosion during overcharging or over-discharging
Customization	Can be customized in shape and capacity according to needs, with strong adaptability	Produced in a standardized manner, with low degree of customization
Cost	Low cost for conventional models, high cost for customized models	Stable production cost and relatively low unit price
Application Scenarios	Suitable for various scenarios such as consumer-grade, industrial-grade, and racing drones	Suitable for low-power, cost-sensitive simple drones or other small devices