1. Product Overview
This manual provides essential information for the safe and effective use of your sea jump 3.7V 380mAh Lithium Battery. This battery is designed as a spare or replacement part for various SYMA quadcopter models, including the SYMA X21, X21W, X26, D15, and X100.
Key Features:
- Capacity: 380mAh
- Voltage: 3.7V
- Ensures extended flight time for compatible drones.
- Undergoes strict quality testing for reliability.

Image 1.1: The sea jump 3.7V 380mAh Lithium Battery, showing its compact design and connector.
2. Safety Information
Read all safety warnings and instructions carefully before use to prevent injury or damage.
- Charging: Only use chargers specifically designed for 3.7V Lithium Polymer (LiPo) batteries. Never leave charging batteries unattended.
- Storage: Store batteries in a cool, dry place away from direct sunlight, heat sources, and flammable materials. Do not store fully charged or fully discharged for extended periods.
- Handling: Do not puncture, impact, short-circuit, or disassemble the battery. Avoid exposing the battery to water or extreme temperatures.
- Damage: If the battery shows signs of swelling, leakage, or damage, discontinue use immediately and dispose of it properly.
- Disposal: Dispose of used batteries according to local regulations. Do not dispose of in household waste.
- Children: Keep batteries out of reach of children.
3. Setup and Installation
This battery is designed for easy installation into compatible SYMA quadcopters.
- Power Off: Ensure your quadcopter is powered off before attempting to install or remove the battery.
- Locate Battery Compartment: Refer to your quadcopter's original instruction manual to locate the battery compartment. This is typically on the underside or rear of the drone.
- Insert Battery: Carefully insert the sea jump 3.7V 380mAh Lithium Battery into the compartment. Ensure the battery fits snugly without force.
- Connect Connector: Align the battery's connector with the drone's power port. Gently push the connectors together until they are securely seated. Ensure correct polarity (red wire to positive, black wire to negative).

Image 3.1: Close-up view of the battery's red and black wires connected to the red JST-style connector, illustrating the connection point.
4. Operating Instructions
Proper charging and discharge practices are crucial for battery longevity and performance.
4.1. Charging the Battery
- Use Correct Charger: Always use the original charger provided with your SYMA quadcopter or a compatible 3.7V LiPo charger.
- Connect: Connect the battery to the charger. Ensure the connection is secure.
- Monitor: Observe the charging process. Most chargers have an indicator light that changes color when charging is complete. Do not overcharge.
- Disconnect: Once fully charged, disconnect the battery from the charger.
4.2. Discharging (Normal Use)
The battery will discharge during normal operation of your quadcopter. It is recommended to stop flying when the drone's low battery warning activates to prevent over-discharge, which can damage the battery.
5. Maintenance
Regular maintenance helps extend the life and performance of your battery.
- Storage Charge: For long-term storage (more than a few days), it is best to store LiPo batteries at a 'storage charge' level, typically around 3.8V per cell. Do not store fully charged or fully discharged.
- Temperature: Store batteries at room temperature (15-25°C or 59-77°F). Avoid extreme hot or cold environments.
- Inspection: Periodically inspect the battery for any physical damage, swelling, or signs of leakage. Do not use a damaged battery.
- Cleaning: Keep the battery and its connectors clean and free from dust or debris. Use a dry, soft cloth for cleaning.
6. Troubleshooting
If you encounter issues with your battery, consider the following common problems and solutions:
| Problem | Possible Cause | Solution |
|---|---|---|
| Battery not charging | Faulty charger, loose connection, damaged battery. | Check charger functionality. Ensure connections are secure. Inspect battery for damage; replace if necessary. |
| Short flight time | Battery degradation, incomplete charge, environmental factors (wind). | Ensure full charge. Consider battery age; replace if significantly degraded. Fly in calm conditions. |
| Battery swelling | Overcharging, over-discharging, physical damage, manufacturing defect. | Immediately discontinue use. Dispose of the battery safely according to local regulations. Do not attempt to charge or use a swollen battery. |
7. Specifications
Detailed specifications for the sea jump 3.7V 380mAh Lithium Battery:
- Battery Type: Lithium Polymer (LiPo)
- Voltage: 3.7V
- Capacity: 380mAh (Milliampere-hours)
- Energy: Approximately 1.4Wh (Watt-hours)
- Cell Composition: Lithium
- Compatibility: SYMA X21, SYMA X21W, SYMA X26, SYMA D15, SYMA X100 Quadcopters
- Quantity: 1 piece per package

Image 7.1: Close-up of the battery's label, displaying 'Fullymax 762725 3.7V 380mAh 1.4Wh' and other markings.
8. Warranty and Support
sea jump products are manufactured to high-quality standards. If you experience any issues or have questions regarding your sea jump 3.7V 380mAh Lithium Battery, please contact the seller or retailer from whom you purchased the product for assistance. Provide your purchase details and a clear description of the issue to facilitate support.