Project idea
Design a 3S Li‑ion battery management system using an STM32 controller that continuously measures pack voltage, current, and temperature, and actuates cutoff via relays/MOSFETs when limits are exceeded to stay within the safe operating area. The build targets EV safety learning by addressing common fire triggers through monitoring, proper charge termination, and thermal protection at the pack level.​
 
Project description
An STM32 microcontroller interfaces with voltage and current sensors and a temperature probe, displays live parameters on a 16x2 LCD, and controls charger and load paths to prevent over/under‑voltage, over‑current, and over‑temperature events in a 3S pack. Charging is supervised so that when full‑charge conditions are detected the system isolates the charger and indicates “battery fully charged,” while in discharge it tracks current draw and cuts off on anomalies to mitigate thermal runaway risk. The approach mirrors BMS functions used in EVs—measurement, computation of limits, and protective switching—adapted to a lab‑scale prototype.​
 
Total list of components (names only)
STM32 controller board​
Temperature sensor​
Voltage sensor​
Current sensor (INA219 module)​
16x2 LCD display​
3S Li‑ion battery pack​
Protection/charging circuitry (relays/MOSFETs/BMS)​
Push buttons/switches​
LEDs​
PCB board​
Resistors​
Capacitors​
Transistors/MOSFETs​
Cables and connectors​
Buzzer​
Enclosure/joystick‑style frame​
Screws and bolts​
 
Features
Battery status monitoring with live voltage, current, and temperature on LCD for visibility and diagnostics.​
Safe charging control with automatic termination and protective cutoff to prevent over‑charge, over‑current, and over‑temperature.​
Thermal monitoring with audible/visual alert and charger/load isolation to reduce thermal runaway risk during charge and discharge.​
 
Applications
Educational EV battery safety demonstrator for e‑bike/e‑scooter pack supervision concepts.​
Lab prototype for teaching BMS monitoring, cutoff control, and fault handling in embedded systems.​
Pre‑integration testbed for pack‑level safety strategies in small mobility or robotics platforms.​
 
Project Includes:
Fully assembled and tested circuit
Circuit diagram
Source code 
(For DIY KITs - only the components will be provided)
 
Project Types:
DIY KIT(Do IT YourSelf KIT) - We are providing only components in this kit for this project
DIY KIT with Code & Circuit Connections - Along with the components, you will get the Code and the Circuit Connections file to help you build the project easily.
Readymade Breadboard - We are providing fully assembled, tested and ready-made project using plug-n-play jumper wires and breadboard with all the other components, code & circuit diagram.
Readymade Soldered - We are providing fully assembled, tested and ready-made project soldered on a PCB with all the other components, code & circuit diagram.
 
Dimensions (cm)
A practical enclosure of approximately 18 × 12 × 7 cm accommodates a 16x2 LCD (typical module footprint ~12.2 × 4.4 cm) and a compact 3S pack with control electronics and wiring clearance. The LCD’s common 122 × 44 mm outline and the pack’s ~2.4 × 6.0 × 7.0 cm dimensions inform the enclosure length and depth allowances for mounting and airflow. For tighter builds using smaller 80 × 36 mm LCD variants, enclosures can be reduced proportionally while maintaining cable bend radius and isolation gaps.​
 
Shipping dimensions (cm)
Use a protective carton around 22 × 16 × 10 cm to allow foam/bubble wrap clearance around the enclosure, LCD face, and battery pack. Retail LCD packaging practices emphasize small boxes with cushioning, which guides box sizing for safe last‑mile shipping of electronics assemblies.​
 
Weight
A typical 11.1 V 2200 mAh 3S pack weighs roughly 150–160 g, forming the bulk of the assembly mass. With controller, sensors, LCD, PCB, wiring, enclosure, and hardware, the finished unit typically falls in the ~350–500 g range depending on enclosure material and relay/MOSFET selection.​
 
Estimate project weight
Approximately 400 g total for a plastic‑enclosure build with one 3S 2200 mAh pack and standard modules and wiring
 
Notes: All the products are made by LearnElectronics India and not for re-sale.