STMicroelectronics Battery Management System (BMS) Solution

STMicroelectronics provides a range of integrated circuits allowing to build up battery management systems for Lithium-Ion batteries. ST's BMS solution demonstrates the benefits of a battery management system for automotive applications, based on the L9963 battery monitoring and protection IC and ST's automotive MCUs.

The L9963 can handle up to 14 Li-Ion battery cells. It can be stacked in a vertical arrangement to monitor up to 15 battery packs – corresponding to a nominal battery voltage of several hundred volts. The IC monitors voltage, current, and temperature at single-cell or stack level with a resolution of 16 bit.

The L9963 is ideally seconded by a microcontroller of the SPC5 family of automotive MCUs, performing the cell balancing and state of health (SOH) and state of charge (SOC) computation based on the data collected through one or several L9963.

The solution proposed here is built with a high-performance MCU from the SPC57 4S Line, featuring up to 1.5Mbytes of Flash memory and 128 Kbytes of RAM. The MCU carries two CAN-FD interfaces, 8 enhanced 12-bit ADCs with extensive triggering capabilities, supports ASIL-D functional safety standards, and is available in QFP100 packages for operating temperatures up to 150°C. The presented implementation can be adapted to a wide range of ST's automotive MCUs depending on the final application's requirements regarding performance and safety level. The highest overall performance can be achieved with the SPC58 G Line, with its up to three cores and memory sizes up to 6Mbyte. It adds hardware security compliance with EVITA and SHE standards.

A further benefit of the L9963 is the universal communication interface compatible with transformer-based or capacitor-based isolation techniques in BMS applications with devices working in different voltage domains.

Benefits

•  Complete battery management system for up to 15 packs with 14 cells each
•  System performance and functionality range scalable by choosing from a wide range of automotive MCUS
•  Supports ASIL-D safety standard and can be extended to EITA and SHE standards
•  Savings on component cost due to robust hot-plug capability (no Zener diode protection needed)

BMS Evaluation Kits

STMicroelectronics Battery Management System (BMS) Solution can be easily evaluated with a scalable kit of evaluation boards, allowing to adapt the solution evaluation to merely every battery partitioning.

The EVAL-L9963-MCU is a complete hardware tool for evaluation of the L9963 integrated circuit for battery management applications together with ST’s high-performance MCU SPC574S64E3. It can be used as a standalone board to develop a 48 V battery management system (BMS) or a lower stage of a distributed BMS. EVAL-L9963-MCU allows the user to manage to 14 channels for cell voltage sensing, one channel for current sensing, and up to 4 analog inputs for temperature sensing (plus an additional onboard NTC to sense PCB temperature). The board provides an onboard microcontroller with preloaded GUI firmware intended to be used with STSW-L9963 PC Graphical User Interface.

The EVAL-L9963-NDS is intended to be used as a single node in a distributed battery management system. EVAL-L9963-NDS is needed to complement the EVAL-L9963-MCU when the total number of battery cells to be managed exceeds 14. The number of nodes to be stacked depends on the total battery voltage. Additional nodes can be added via additional EVAL-L9963-NDS. A maximum of 14 total nodes beyond the base node EVAL-L9963-MCU can be stacked.

In case the L9963 is combined with another MCU, the EVAL-L9963 board can be used as a lower stage for the battery management system. It is similar to the EVAL-L9963-MCU but provides a connector for interfacing with an external microcontroller (board).

BMS Evaluation Kits Features

•  Flexible and modular evaluation kit, allowing to evaluate ST’s solution battery management systems on a large variety of Li-Ion battery stacks (up to 15 x 14 cells)
•  Powerful automotive MCU SPC574S64E3 included
•  Firmware preloaded in the SPC574S64E3 for immediate use with the Graphical User Interface STSW-L9963
•  A Graphical User Interface (GUI) for evaluation of all the functions of the BMS on up to 15 nodes, including
•  Cell current and voltage and temperature measurement
•  Coulomb counter
•  Control of balancing
•  Diagnostic and register control of L9963
•  Data logging and export