Lead Firmware Engineer – Bess

Role Description

Kimbal is developing its own Battery Management System (BMS) and Energy Management System (EMS) for utility-scale Battery Energy Storage Systems (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.

Key Responsibilities

• Develop BMS firmware across the module, rack and system tiers on embedded microcontrollers: drivers, RTOS integration, bootloader and secure firmware-update modules.

• Implement battery protection and safety logic: over/under-voltage, current and temperature protection, isolation-fault detection, sensor-failure handling and thermal-event response.

• Implement contactor and pre-charge control, rack paralleling, and fault diagnostics with event logging.

• Implement and tune battery algorithms: state-of-charge, state-of-health and state-of-power (power limit) estimation, and cell, module and rack balancing.

• Parameterise cell models from Kimbal’s cell characterisation data, and validate the algorithms 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 automated hardware-in-the-loop (HIL) testing.

• Support lab validation, certification testing and field commissioning of pilot deployments, and use field data to improve firmware and algorithms.

Current Challenges

• Shipping safety-critical firmware for a new product on a delivery date committed to the customer.

• Building accurate, robust state estimation for LFP chemistry, whose flat voltage curve makes estimation hard. compromising safety or cycle life.

• Building a firmware and algorithm platform that adapts across cell formats and suppliers with minimal rework.

Job Requirements

• B.Tech / M.Tech in Electrical, Electronics, Computer Science or Embedded Systems from 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 or similar) and bare-metal firmware.

• Working knowledge of CAN, SPI, I2C and UART, and of debugging with JTAG, logic analysers 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.