BEI Maximus UL 20A Battery | 14S1P 54.04V 21.1Ah High-Energy Density UAV Pack

The BEI Maximus UL 20A 14S1P Battery Pack is an ultra-high-energy battery system designed for UAVs, aerospace platforms, robotics, and other weight-critical applications where maximizing stored energy while minimizing battery mass is essential. Built using BEI’s Maximus UL 20A lithium-metal cells, the pack combines a 519 Wh/kg cell-level gravimetric energy density with high discharge capability and excellent low-temperature performance. The 14S1P configuration provides up to 21.1 Ah typical capacity and 1,141 Wh of energy, making it particularly well suited for long-endurance aircraft and high-energy aerospace applications. Cell Datasheet BEI specifies operation down to −35°C, with the cells capable of up to 8C continuous discharge at −20°C. This combination of energy density, power capability, and low-temperature operation makes the Maximus UL platform particularly attractive for aircraft where battery mass directly affects endurance, payload capacity, and overall system performance. Technical Specifications Configuration: 14S1P Nominal Voltage: 54.04 V Maximum Charge Voltage: 60.2 V Discharge Cutoff Voltage: 42.0 V Capacity Typical: 21.1 Ah @ 0.1C Minimum: 20.0 Ah @ 0.1C Rated: 19.6 Ah @ 1C Energy Typical: 1,141 Wh @ 0.1C Minimum: 1,081 Wh @ 0.1C Rated: 1,053 Wh @ 1C Charge Current Standard: 4 A (0.2C) Maximum: 20 A (1C) Discharge Current Standard: 20 A (1C) Maximum Continuous: 100 A (5C) Maximum Continuous @ −20°C: 160 A (8C) Maximum Discharge ≤300 sec: 200 A (10C) Maximum Pulse ≤10 sec: TBD by BEI Internal Resistance Cell ACIR: ≤1.6 mΩ @ 1 kHz, 30% SOC Cell DCIR: ≤4.0 mΩ @ 30% SOC Pack-level resistance varies with interconnects, wiring, connectors, and final configuration. Environmental Specifications Charge Temperature: +10°C to +45°C Discharge Temperature: −35°C to +71°C Storage Temperature: 0°C to +45°C Maximum Cell Body Temperature: 90°C Mechanical Specifications Cell Weight: 157 g each Cell-Level Mass (14 cells): ~2.20 kg Finished Pack Weight: Dependent on final construction, wiring, connector, protection, and enclosure requirements Cell Performance Cell-Level Gravimetric Energy Density: 519 Wh/kg @ 0.1C Cell-Level Volumetric Energy Density: 1,282 Wh/L @ 0.1C Cycle Life: 70 cycles — 0.2C charge / 1C discharge, 100% DOD to 80% SOH 30 cycles — 1C charge / 2C discharge, 100% DOD to 80% SOH Cell Certification: UN 38.3 BEI Maximus UL 20A Datasheet.pdf Availability Lead Time: Approximately 3 weeks BEI Maximus UL 20A cells are currently intended for testing and evaluation applications, with availability subject to supply. Custom pack configurations, connectors, wiring, BMS integration, mechanical packaging, and system-level engineering are available through Zero Point Energy Labs. BEI Maximus UL 20A Datasheet.pdf For full technical documentation, integration support, or custom battery configurations, please contact our team.