AYAA · EF-004 SMART POWER FOR UAVs
A smart BMS for 12S–18S NMC Li-ion drone battery packs, supporting 120A charge and 250A continuous discharge. It integrates cell and total-voltage monitoring, 50mA passive balancing, configurable protection, CAN communication, and host-software access to real-time and historical battery data.
12–18S CONFIGURATION CHECK
Compare your battery-pack configuration, voltage range, communication protocol and installation space with the EF-004 specification before integration.
COMPATIBLE 18S UAV BATTERY PACKS
180 × 90 × 15 mm
EF-004 12–18S 250A Smart UAV BMS
Cell and total-voltage monitoring, configurable protection, 50mA passive balancing,
CAN communication and host-software access.
ENGINEERING SPECIFICATIONS
Review the 12–18S NMC Li-ion battery-pack configuration, then confirm voltage sensing, balancing, communication and installation requirements before system integration.
| Battery and Electrical Configuration |
Specification |
|---|---|
| Product Model | EF-004 |
| Battery Chemistry | NMC Li-ion |
| Supported Cell Configuration | 12–18S |
| Nominal Cell Voltage | 3.2 V / 3.7 V |
| Cell Voltage Detection Range | 0–5 V |
| Total Voltage Detection Range | 30–80 V |
| BMS Operating Voltage | 20–90 V |
| BMS Operating Temperature | −40°C to 65°C |
| Port Configuration | Common Port · CAN · RS485 |
| Dimensions | 180 × 90 × 15 mm |
| Weight | 210 g |
| Measurement, Balancing and Communication |
Specification |
|---|---|
| Cell Voltage Detection Accuracy | ±5 mV |
| Total Voltage Accuracy | ≤±1% |
| Current Measurement Accuracy | ±60 mA (<3 A); ±3% (≤200 A) |
| Temperature Sensor Type | NTC |
| Temperature Measurement Range | −40°C to 105°C |
| Temperature Measurement Accuracy | ±2°C |
| SOC Estimation Accuracy | 1%–3% after one charge/discharge cycle |
| Passive Balancing Current | 50 mA |
| Balancing Enable Voltage | 4000 mV |
| Balancing Enable Voltage Difference | 50 mV |
| CAN Communication | CAN; supports DroneCAN and selected flight-control protocols |
EF-001 SMART BMS FUNCTIONS
Four operating scenarios: in-flight temperature warning, precharge, system communication and SOC estimation.
CONNECTED BATTERY DATA
Connect EF-004 to the flight-control system through CAN and use RS485 host software to view battery status, configure parameters and access historical records.
Confirm the flight-controller protocol, CAN settings and RS485 connection before integration.
Product Validation
Watch the EF-004 validation video covering BMS wiring, host-software connection, continuous-discharge overcurrent duration, temperature rise and project-specific requirements.
Choose the standard EF-004 platform when its battery range and interfaces match your project, or share your requirements for an engineering review.
A ready platform for 12–18S NMC Li-ion UAV battery packs with a common-port design.
For battery packs, interfaces or control requirements outside the standard EF-004 configuration.
SHENZHEN AYAA TECHNOLOGY CO., LTD.
Request the EF-004 datasheet to review electrical specifications, wiring sequence, CAN communication, software functions and warranty information.
12–18S NMC Li-ion UAV BMS specifications, 180 × 90 × 15 mm dimensions, connection sequence, protection settings, CAN and RS485 details.
Request Datasheet →Review pack-negative, pack-positive, 12–18S cell-voltage, CAN, RS485 and temperature-sensor connections before power-on.
Request Datasheet → System ConnectionReview DroneCAN, UAVCAN and selected flight-control protocol support, plus RS485 host-software data, settings, records and SWG firmware updates.
Request Datasheet → Engineering SupportPrepare battery series count, current profile, flight-controller protocol and installation space for review.
Contact Engineering → WarrantyReview warranty coverage, use conditions and exclusions for the EF-004 product.
Request Warranty Details →EF-004 is a common-port smart BMS for 12–18S NMC Li-ion UAV battery packs, specified for 120 A charging and 250 A continuous discharging. To check compatibility, provide your cell model, series count, maximum pack voltage, continuous load, peak current and peak duration. Battery capacity alone does not determine compatibility; the cells, wiring and installation must also support the required load.
Use the EF-004 wiring diagram for your exact 12–18S configuration. Verify pack polarity, cell-voltage harness order, connector pin assignments and temperature-sensor connections before power-on. EF-004 uses a common charge/discharge port; confirm the power and communication connections against its datasheet rather than relying on another BMS model's pinout.
EF-004 provides CAN communication and supports integration with DroneCAN, UAVCAN and selected flight-control protocols. Compatibility depends on the flight controller, firmware and configured protocol, not simply the presence of a CAN port. Confirm the required protocol and battery messages with Ayaa before integration, then verify that the flight controller receives the expected battery data.
The EF-004 host software displays individual cell voltages, total pack voltage, temperatures, charge/discharge current, remaining capacity, state of charge (SOC) and MOS status. It connects through RS485 at 19,200 bps and supports parameter settings, historical records and data export. The specified SOC accuracy is 1%–3% after one charge-discharge cycle following initial power-up.
EF-004 uses 50 mA passive cell balancing. Passive balancing removes a small amount of charge from selected higher-voltage cells rather than transferring energy between cells. Balancing is conditional, so an inactive status does not by itself indicate a fault. Check cell voltages, voltage differences, operating mode and the balancing settings confirmed for your supplied firmware.
EF-004 uses different protection behavior for different faults. The datasheet states that cell over-discharge cutoff and discharge-overcurrent levels 1 and 2 are inactive during flight. Short-circuit protection remains active both on the ground and in flight and can turn off the discharge MOSFET. Discharge high- and low-temperature conditions generate warnings without switching off discharge. Confirm flight-state detection and flight-controller responses during integration; EF-004 does not guarantee uninterrupted power under every fault condition.
Both models cover 12–14S battery packs. Compare continuous load, charging requirements, installation space and communication needs. EF-004 extends to 18S with a 250 A discharge rating; EF-003 covers 8–14S in a lighter board.
| Selection Question |
EF-004
12–18S / 250 A Discharge
|
 EF-003
8–14S / 120 A Recommended Discharge
|
|---|---|---|
| Which Battery Chemistry Is This Comparison For? | NMC Li-ion UAV battery packs | NMC Li-ion UAV battery packs |
| Will It Support My Battery Series Count? | 12S–18S | 8S–14S |
| What Continuous Discharge Current Is Specified? | 250 A continuous discharge | 120 A recommended; 150 A maximum continuous capability |
| What Charging Current Is Specified? | 120 A charge current | 80 A recommended; 150 A maximum continuous capability |
| Will It Fit My Installation Space? | 180 × 90 × 15 mm | 150 × 90 × 15 mm |
| How Much Does the BMS Weigh? | 210 g specified BMS weight | 127 g specified BMS weight |
| How Does It Connect to the UAV and PC? | CAN with DroneCAN / UAVCAN integration; RS485 host software | CAN 2.0B; Type-C connection to the designated PC tool |
| When Should I Consider This Model? | For 15–18S packs, or 12–14S projects requiring the higher specified current rating | For 8–11S packs, or 12–14S projects within its recommended current limits where lower weight matters |
| Request EF-004 Review → | View EF-003 Details → |
EF-004 UAV BMS INTEGRATION
Share your 12–18S UAV battery-pack and flight-control requirements. Our team can help you confirm whether the EF-004 250A smart BMS fits your inspection, monitoring or surveying UAV project.