Lead Firmware Engineer – Bess

Kimbal; Bengaluru; On-site; INR 1,200,000 - 1,900,000; Full time

Job summary

Kimbal is developing its own Battery Management System (BMS) and Energy Management System (EMS) for utility-scale BESS. We are looking for a Firmware Engineer to write the embedded software and battery algorithms that protect our systems and extract the most usable energy from every cell.

You will work from bare-metal drivers to safety logic and state estimation, in close partnership with the hardware, controls and systems engineers, and see your code run on systems deployed on India's grid.

Qualifications

• 4–7 years of embedded firmware development experience.
• Strong embedded C/C++ on microcontrollers with RTOS exposure.
• Working knowledge of CAN, SPI, I2C, UART and related debugging tools.
• Solid grounding in lithium-ion battery fundamentals or state estimation.

Responsibilities

• Develop BMS firmware across module, rack and system tiers on embedded MCUs.
• Implement battery protection and safety logic for voltage, current and temp.
• Control contactor/pre-charge, rack paralleling and fault diagnostics with logs.
• Develop and tune SOC, SOH and power limit estimation, balancing algorithms.
• Parameterise cell models from data and validate against lab/field data.
• Develop CAN/Modbus interfaces to EMS and plant controller; ensure traceability.
• Ensure safety requirements from hazard analysis are reflected in code and tests.
• Write testable code with unit tests, static analysis, and HIL testing.
• Support lab validation, certification, and field deployments; use data to improve firmware.

Skills

Embedded C/C++

RTOS experience

CAN/SPI/I2C/UART

Debugging tools

Kalman filtering

Education

B.Tech / M.Tech in Electrical, Electronics, CS or Embedded Systems

Tools

FreeRTOS

Git

CI/CD

Python

MATLAB/Simulink

Job description

Role Description

Kimbal is developing its own Battery Management System (BMS) and EnergyManagement System (EMS) for utility-scale Battery Energy Storage Systems (BESS). Weare looking for a Firmware Engineer to write the embedded software and batteryalgorithms that protect our systems and extract the most usable energy from every cell.

You will work from bare-metal drivers to safety logic and state estimation, in closepartnership with the hardware, controls and systems engineers, and see your code run onsystems deployed on India's grid.

Key Responsibilities

• Develop BMS firmware across the module, rack and system tiers on embeddedmicrocontrollers: drivers, RTOS integration, bootloader and secure firmware-updatemodules.
• Implement battery protection and safety logic: over/under-voltage, current andtemperature protection, isolation-fault detection, sensor-failure handling andthermal-event response.
• Implement contactor and pre-charge control, rack paralleling, and fault diagnosticswith event logging.
• Implement and tune battery algorithms: state-of-charge, state-of-health andstate-of-power (power limit) estimation, and cell, module and rack balancing.
• Parameterise cell models from Kimbal's cell characterisation data, and validate thealgorithms against lab and field data.
• Develop communication stacks and interfaces to the EMS and plant controller (CAN,Modbus TCP/RTU).
• Trace safety requirements from hazard analysis through to code and test.
• Write testable, well-reviewed code: unit tests, static analysis, and automatedhardware-in-the-loop (HIL) testing.
• Support lab validation, certification testing and field commissioning of pilotdeployments, and use field data to improve firmware and algorithms.

Current Challenges

• Shipping safety-critical firmware for a new product on a delivery date committed tothe customer.
• Building accurate, robust state estimation for LFP chemistry, whose flat voltage curvemakes estimation hard.compromising safety or cycle life.
• Building a firmware and algorithm platform that adapts across cell formats andsuppliers with minimal rework.

Job Requirements

• B.Tech / M.Tech in Electrical, Electronics, Computer Science or Embedded Systemsfrom a premier institute.
• 4-7 years of experience in embedded firmware development, ideally for BMS, EV,power electronics or industrial control systems.
• Strong embedded C/C++ on microcontrollers; experience with an RTOS (FreeRTOS orsimilar) and bare-metal firmware.
• Working knowledge of CAN, SPI, I2C and UART, and of debugging with JTAG, logicanalysers and oscilloscopes.
• Solid grounding in lithium-ion battery fundamentals, signal processing or estimation(e.g. Kalman filtering) is a strong plus.
• Preferred: exposure to functional-safety practices (IEC 61508 / ISO 26262), MISRA C,or model-based development (MATLAB/Simulink).
• Preferred: Git, CI/CD and Python for test automation.