Cobham Power Products

Providing the aerospace & avionic markets with Battery Electronics Units (BEUs) to promote and facilitate the safe use of large Li-Ion batteries on missions greater than 20 years, high-speed power controllers and voltage regulators.

Contact: 800-645-8862

Battery Electronic Units (BEU)

Providing your HiRel Databus for HiRel Applications

Cobham's Plainview facility's new Battery Electronics Units provide autonomous cell balancing for Lithium-Ion batteries.

A series stack of Lithium- Ion cells are accurately charge balanced so the battery can be utilized to its fullest capacity. The cell balancing circuitry uses a set of bi-directional DC-DC converters that tie the cells of the battery to a common share bus. Cell charge is distributed among the multiple cells so that the charge of each cell is brought to the average charge of the other cells. Cell balancing can, therefore, be performed at any state of charge of the battery.

Individual cell voltage monitors keep track of cells that may exceed charge limits. Precise voltage telemetry is provided for all cells and the battery. Optional features include reconditioning load control and cell bypass device drivers.

BEU Family: Standard Features
  • Cell voltage monitoring and telemetry
  • Cell balancing to within +/-5.0mV
  • Cell voltage monitoring accuracy +/-10mV
  • Total battery voltage monitoring accuracy +/-0.3% of full scale
  • MIL-STD-1553B telemetry for data logging and monitoring
  • Discrete output lines for critical signaling with user definable thresholds:
    • Over-voltage protection -- 4.40V typ
    • Cell voltage high -- 4.20V typ
    • Cell voltage low -- 3.20V typ

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BEU News

  • Cobham electronics arrive at Jupiter aboard NASA's Juno Spacecraft. Find out more by viewing our Press Release.

BEU at Jupiter on Juno!

  • Advance Your Program with Cobham and ATSP4 - Advanced Technology Support Program. Learn More

Available Battery Electronic Unit (BEU) Products

Battery Electronics Units
Part Number
Cells Features / Description / Size
BEU8635-088 Balancing for 8-cell battery, with cell voltage monitoring and telemetry. Size: 11.50" L x 2.30" W x 5.25" H
BEU8635-1212 Balancing for 12-cell battery, with cell voltage monitoring and telemetry. Size: 11.50" L x 2.30" W x 5.25" H
BEU8635-2424 Balancing for 24-cell battery, with cell voltage monitoring and telemetry. Size: 11.50" L x 2.30" W x 5.25" H
BEU8636-088 Balancing for 8-cell battery, with cell voltage monitoring and telemetry and cell bypass device drivers. Size: 11.50"L x 3.30"W x 5.25"H
BEU8636-1212 Balancing for 12-cell battery, with cell voltage monitoring and telemetry and cell bypass device drivers. Size: 11.50"L x 3.30"W x 5.25"H
BEU8636-2424 Balancing for 24-cell battery, with cell voltage monitoring and telemetry and cell bypass device drivers. Size: 11.50"L x 3.30"W x 5.25"H
BEU8637-088 Independent balancing for two 8-cell batteries or redundant balancing for a single 8-cell battery, with cell voltage monitoring and telemetry. Size: 11.50" L x 4.00" W x 5.25"H
BEU8637-1212 Independent balancing for two 12-cell batteries or redundant balancing for a single 12-cell battery, with cell voltage monitoring and telemetry. Size: 11.50" L x 4.00" W x 5.25"H
BEU8638-088 Independent balancing for two 8-cell batteries or redundant balancing for a single 8-cell battery, with cell voltage monitoring reconditioning load control and cell bypass device and telemetry, drivers. Size: 11.50" L x 5.20" W x 5.25" H
BEU8638-1212 Independent balancing for two 12-cell batteries or redundant balancing for a single 12-cell battery, with cell voltage monitoring and telemetry, reconditioning load control and cell bypass device drivers. Size: 11.50" L x 5.20" W x 5.25" H
BEU8640-2424 Dual redundant balancing for up to 24-cell battery, with cell voltage monitoring and telemetry, reconditioning load control and cell bypass device drivers. Size: 11.50" L x 5.30" W x 5.25" H
BEU8642-EVAL8 Balancing for 8-cell battery, with cell voltage monitoring and telemetry, temperature monitoring, built-in test, RS-232 output for data logging, LCD display for cell voltage, temperature and status. Size: 12.00" L x 9.00" W x 2.65" H
BEU8642-EVAL18 Balancing for 8-cell battery, with cell voltage monitoring and telemetry, temperature monitoring, built-in test, RS-232 output for data logging, LCD display for cell voltage, temperature and status with external fuses. Size: 12.00" L x 9.00" W x 2.65" H
† Product in development.
Battery Interface Electronic Assembly
Part Number
Cells Features / Description
BIE86788 – 32 The Battery Interface Electronic (BIE) assembly provides an interface between a space electrical power system (EPS) and its' Lithium Ion batteries vehicle (comprised of 8 to 32 cells). The BIE provides real time battery status monitoring, telemetry and control, and ensures safe battery operation throughout the mission life. It is fully space qualified and is designed to support a wide range of missions including LEO, MEO, GEO, MEO, interplanetary and manned flight. The BIE assembly inludes three primary components: the Voltage/Temperature Monitoring Module (VTM), the Over Charge Protection Module (OCP), and the Battery Isolation Switch. Size: 6.95" W x 11.71" L x 4.50" H