Battery management systems (BMS)
We develop and produce electronic modules for the control/monitoring of Li-ion batteries in different applications. Such modules are also called battery management systems, BMS in short. Li-ion batteries require corresponding management systems in order to use their full potential, to protect them against overcharge and total discharge, for the safe operation, and as an interface to other systems. The efficiency, reliability, safety and service life of the Li-ion batteries is largely depending of the effectiveness of the BMS.
Features of our BMS
- Control and monitoring of every individual Li-ion cell by means of precise balancing with a protection against overcharge and total discharge (adjustable to specific requirements and customer requests)
- Cascadable master slave topology for power storage up to 1,000 V and 1 MWh by means of serial and parallel interconnection of cells and cell strings
- Extensive safety concept with configuration and fault memory
- Low energy consumption, even for a long storage time of the battery system
- Galvanically insulated inputs and outputs
- Temperature measurement and monitoring corresponding to the constructive assembly
- Secure communication via CAN bus and other interfaces
- Extensive monitoring and diagnostics tool with graphic user interface
BMS and tools from our range (no longer available)
- BMS for Li-ion starter batteries
- BMS for Li-ion battery packs
- Modular BMS for Li-ion storage batteries
- Modular BMS for Li-ion power storage
- Monitoring / diagnostics tools (diagnostics tool BMS – Monitor, BMS module scanner)
Functions of the diagnostics tool BMS – Monitor:
- Monitoring
- Logging
- Communication
Functions of the BMS – module scanner:
- Parametrisation of limit values BMS module
- Reading of module specifications / fault events from InfoFlash
- Access to flash memory via JTAG interface
BMS for Li-ion starter batteries (no longer available)
System for 4-cell battery
Functions:
- Cell voltage monitoring for 4 Li-ion cells (resolution 1.5 mV/Bit, measurement error max. 0.25%
- Passive cell balancing
- Cell balancing current 200…450 mA
- Overcharge and total discharge monitoring (signalling of relevant thresholds)
- Two potential-free switching outputs for overcharge and total discharge signalling
- Temperature measurement “on chip” and 2 external temperature sensors
- Active / sleep modes for reduced power consumption
- Inverse-polarity protection jump start
- Configuration / fault memory
- Real-time clock (RTC) for system time
- LIN bus for diagnostics / communication
BMS for Li-ion battery packs (no longer available)
System for Li-ion batteries up to 48 V
Functions:
- Cell voltage monitoring for max. 12 Li-ion cells (resolution 1.5 mV/Bit, measurement error max. 0.25 %),
- Passive cell balancing
- Cell balancing current 200…450 mA
- Overcharge and total discharge monitoring (signalling of relevant thresholds),
- Two potential-free switching outputs for overcharge and total discharge signalling
- Temperature measurement “on chip” and 2 external temperature sensors
- Active / sleep modes for reduced power consumption
- Inverse-polarity protection jump start
- Configuration / fault memory,
- Real-time clock (RTC) for system time
- LIN bus for diagnostics / communication
- Separate pin for IBS current sensor
Modular BMS for Li-ion storage batteries (no longer available)
System for Li-ion storage batteries up to 170 V
Functions:
- Cell and string voltage monitoring for max. 48 Li-ion cells (resolution 1.5 mV/Bit, measurement error max. 0.25 %),
- Simplified master-slave-topology with max. 4 modules,
- Passive cell balancing
- Cell balancing current 200…450 mA
- Overcharge and total discharge monitoring (signalling of relevant thresholds),
- Two potential-free switching outputs for overcharge and total discharge signalling,
- Temperature measurement depending on the module „on Chip“ and 2-8 external temperature sensors (depending on the number of modules),
- Active / sleep modes for reduced power consumption
- Inverse-polarity protection jump start
- Configuration / fault memory,
- Real-time clock (RTC) for system time,
- LIN bus for diagnostics / communication
- Separate pin for IBS current sensor
Modular BMS for Li-ion power storage
System for Li-ion power storage up to 1,000 V
Functions:
- Organisation in master-slave-topology with 1 master module and max. 32 slave modules
- Monitoring of max. 384 cells is possible
- Serial and/or parallel interconnection of the cells within the same memory is possible
Master module
- System on Chip (SoC) FPGA with ARM Cortex-M3 processor
- Optional: 16 MByte Flash and 4 MByte SRAM
- Supply voltage 9 – 36 V DC
- 2x galvanically separated CAN interfaces
- 4x Modbus with RS485
- 8x optically insulated inputs
- 8x optically insulated switching outputs
- 2x galvanically separated analog inputs for voltage metering up to 1,000 V
Slave module
- Cell voltage monitoring for min. 4 to max. 12 Li-ion cells
- Passive cell balancing with compensating currents up to approx. 500 mA onboard without cooling, or up to approx. 4 A with cooling
- Overcharge and total discharge monitoring
- Temperature measurement depending on module „Onchip“ and 2 external temperature sensors (NTC resistors)
- Active / sleep modes for reduced power consumption
- Configuration / fault memory,
- Real-time clock (RTC) for system time
- Inverse-polarity protection jump start
- Data memory 32 MBit for the storage of the configuration, analysis and error data
- Modbus via galvanically separated RS485 to the master module
- Slave module also usable independently with limited functionality
Monitoring / diagnostics tool for our BMS
For commissioning and tests, an adjusted monitoring and diagnostics tool is provided for every version of our BMS modules.
Diagnostics functions:
- Monitoring
Cell voltages of the connected Li-ion cells with 1.5 mV resolution,
Charge state of the cells (red=overvoltage; green=ok; blue=balancing necessary; yellow=undervoltage),
Display of the total voltage of the string,
Voltage curve of every cell (graphic) in blocks,
Display of the total current charge / discharge,
Logic states of the tabs of the “balancing chip”,
Temperature measurement at 2 positions of the string,
Configuration
Display of the tabs of the balancing chip,
Display of under/overvoltage thresholds,
Setup of the date/time of the real-time clock (RTC) (if available) - Logging
Manual storage of the temporal voltage curves as an image file,
Cyclic storage of all captured data including error/status information - Communication
BMS - USB-Port PC via interface converter