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BMSlion - Lithium Battery Management System

BMSlion v2 is a modular Lithium Battery Management System designed entirely by BATKON. On the "LCU-Lithium Control Unit", which is the main board of the product, there are circuits that can measure the voltages of lithium cells up to 16 series and the temperature of the cell block with up to 3-6 NTC temperature sensors. With the "Passive balancing" daughter board that can be installed on the LCU, it can balance the cell voltages of the package by discharging the cells with a higher voltage than the others by drawing 180mA current. When the "Active Balance" daughter board is installed, charge transfer between cells can be made up to 1.5A.

LCU Board

BMSlion Boxed

(Click on the picture to see 3D object)

BMSlion Battery Management System has RS485 and CAN interfaces. Optional "isolated CAN" interface support electrical isolation up to 1500V. By using this structure, High Voltage Battery Management System can be created that can control hundreds of cells by using more than one BMSLion in electric vehicles or energy storage system applications created by laying a high number of cells. In this case, one of the BMSlions becomes a "Master" and the other slave BMSlions over the isolated  CAN or Wi-Fi interface. Master BMSlion provides management of the entire package by collecting information from the slaves. It can adapt to the desired message structure in CAN 2.0b format on CANBus. It also supports industry standard CAN protocols such as CANopen 418 and SAE J1939. In this context, protocol adaptations can be made easily so that different devices can talk to CANopen or J1939 supported CAN communication ports.

Thanks to the "Automotive Grade" connectors on the BMSlion rear panel, the cable connections are designed to work in vibrant environments. In this way, it can be used in automotive applications such as Electric Vehicle, Go-Kart, Forklift, Golf car etc. 

BMSlion save data to log files in seconds to MicroSD compatible flash drives connected to the MicroSD connector on the board. By importing into Excel, these logs can be formatted and converted into desired graphics.

Software updates of BMSlion can also be done via MicroSD memory or Wi-Fi. The software of the module can be updated automatically by reading the "firmware.bin" file placed in the \ firm \ folder in the MicroSDMemory during boot. In addition, system settings can be import/export via Web interface.

There are 4 MOSFET switched outputs on the LCU board. Contactor coils connected to these connectors can be controlled by the LCU. In this way, structures that can turn the current on and off in the Charge (CHG) and Discharge (DSG) directions are supported. The PRE drive output connector can also be used to support applications that require n-charge or pre-discharge. AUX output is also available to drive relay/contactor units that control Cooling/Heating or additional alarm systems.

With the Embedded Web server interface accessed via Wi-Fi SSID on the LCU card, management parameters can be set for the module and instant data can be viewed on the panel.


It is designed to control the "Charge-Discharge Control - CDC" module, which includes MOSFET switches that can turn on and off charge and discharge through the "Probe" connector on the BMSlion module and a hall effect current sensor. It can cut the charge or discharge unidirectionally by turning the MOSFETs on the CDC on and off. In this way, it can be kept ready for discharge in "standby" applications, even though it cuts off the charge. The current sensor on the CDC can be 50-100 A type. In higher current applications, external hall effect current sensor and contactors with suitable current for charge discharge control can be used instead of CDC.


Technical Data:

Dimensions :

LCU Board : 22 x 70 x 113mm (Y x G x D),    26 gr

BMSlion Boxed : 32 x 83 x 115 (Y x G x D),    70 gr

Electrical :

Supply voltage: 12… 72 VDC

Environmental :
• Working Temperature: -40 ... 85 °C                    • Relative Humidity: 90% RH

BMSLion Features:

  • 3-16 ports Can measure cell voltage with 1-2 mV precision (0.5 – 4.5V)

  • Cell Balancing Method: “Passive Balancing” (75 or 180 mA balancing current) or : “Active Balancing” (balancing current up to 1500 mA)

  • Cell Protection Features: If any cell exceeds the "Over Voltage Protection" (COV 2.5 - 4.5V adjustable) value in charging or goes below the "Under Voltage Protection" (CUV 0.5 - 3.0V adjustable) voltage during discharge, the current is cut off.

  • MicroSD Interface: MicroSD card can be used to save system logs on memory or to update firmware and load system parameters at boot.

  • It can transfer data to remote servers with TCP/IP protocols over Wi-Fi. Data can be viewed from Phone/Tablet/PC via Web browser via the embedded web server.

  • Informs the user of System Status and Alarms with RGB LED.

  • It measures cell temperatures with a 3 port NTC type temperature sensor. NTC can be upgraded to 8.

  • With 2 port MOSFET driver (<5A pull down), it can turn on/off charge/discharge power MOSFETs or contactors.

  • It can perform PRE-Charger/Discharge (<1A) function with 2 port High Side MOSFET switch.

  • It can read packet current as voltage from Hall Effect Current Sensor. (2 ports)

  • Can read packet current as voltage from 1-5 mOhm shunt current sensor

  • It can communicate with management systems via optional RS485 interface.

  • With the optional Isolated or Non-isolated CAN-Bus interface, it can communicate between LCUs, Inverter and PCS or electric car ECU/VMS units.

BMSLion Embedded Web Interface

BMSlion TFT-LCD Screenshots

A TFT LCD screen that can be connected to BMSlion via the JST type connector on it. With the embedded software we developed on the LCD display module, the data coming from the BMS card is displayed to the user with appropriate pages and images and is updated every second. Different screen arrangements and different pages can be made according to the needs of the application. Different screen sizes  2.4, 4.3, 5.0, 7.0 and 11.0 inches are supported.

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