XL Batteries

XL Batteries, a Massachusetts-based development stage company focused on long duration energy storage at the grid level. We are growing a highly collaborative team with the addition of a Software and Controls Engineering Leader. Our mission is to create a safe, low-cost and reliable grid-scale battery that will enable the transition of the grid from fossil fuels to renewable sources. We are a fast paced, nimble startup where no job is too big or small, and where we strive to ask ourselves the hard questions before problems arise.

XL Batteries is an equal opportunity employer.

Marlborough, MA is a beautiful small city in central Massachusetts, surrounded by quaint Massachusetts towns and within a day-trip distance of the Berkshires, White Mountains, and Cape Cod. For those who prefer a more urban lifestyle, we are located directly off I-495 within easy commuting distance of Boston and Cambridge (30-40 minutes), Worcester (25 minutes), Nashua, NH (45 minutes) and Providence, RI (50 minutes).

A Software & Controls Engineering Leader is needed to lead the development of a next‑generation Battery Management System (BMS) and Energy Management System (EMS) for a new form of grid‑scale energy storage. This role blends hands-on engineering with technical leadership, guiding a small, multidisciplinary development team responsible for both software and controls architecture.

The ideal candidate is equally comfortable designing PLC logic, building CI/CD pipelines, architecture of external control software, and communicating complex technical concepts in a clear, accessible way. This position is central to shaping the control strategy, deployment, and long‑term maintainability of the system.

• Lead the design and implementation of the system‑level BMS and associated control software.
• Serve as both leader and hands‑on technical contributor within a small engineering team.
• Define control strategies, communication architectures, and deployment models for a distributed array of PLCs.
• Translate complex engineering concepts into simplified explanations for internal and external stakeholders.
• Manage a Kanban‑based development workflow, ensuring clear prioritization and predictable delivery.

• Select PLC, I/O, and industrial networking hardware appropriate for grid‑connected energy systems.
• Develop core PLC logic using Structured Text, Python, C++ and Ladder Logic.
• Integrate industrial protocols such as Modbus, IEC 61850, or DNP3.
• Support system simulation, hardware‑in‑the‑loop testing, and lab‑based development.
• Develop external supervisory control software to manage fleets of PLCs.
• Build and maintain CI/CD pipelines using GitLab.
• Implement containerized services using Docker and manage virtualized environments (VMs).
• Design and maintain databases for sensor and telemetry data.

• Mentor engineers, review code, and enforce high standards for reliability and maintainability.
• Collaborate cross‑functionally with hardware, power systems, and product teams.

• Bachelor’s Degree in Engineering preferably in Software and Controls
• Prior work on energy storage systems, microgrids, or utility‑scale controls.
• Experience with simulation frameworks or hardware‑in‑the‑loop environments.
• Background in safety‑critical or high‑reliability industrial systems.

• Strong proficiency in Python and C/C++.
• Experience with multithreaded application development.
• Hands‑on PLC programming using Structured Text or Ladder Logic.
• Industrial communication protocols: Modbus, IEC 61850, or DNP3 (any one required; more is a plus).
• Experience with Git, GitLab CI/CD, and modern build pipelines.
• Familiarity with Docker, VMs, and containerized deployment strategies.
• Experience collecting and storing sensor/telemetry data in databases.
• Knowledge of message frameworks like AMQP or ZeroMQ, MQTT and OPCUA.
• Deep understanding of server, router, and network architectures.

• Exposure to DC‑side and/or AC‑side power systems equipment.
• Experience with grid interfaces, grid‑connected devices, or utility‑scale systems is a strong plus.
• Experience interacting with electricity utilities in the deployment of 3rd-party add-ons for substation is a strong plus.

Apply through xl-batteries.breezy.hr