Weekend Assembly Jobs in Boston, MA (NOW HIRING)

Requisition Number: XL2026-005

Position: Battery Assembly Technician

Location: Marlborough, MA

XL Batteries is a Massachusetts-based development stage company focused on long duration energy storage at the grid level. We are creating a highly collaborative team with the addition of a Battery Assembly Technician. 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. We offer competitive salary and benefits, including healthcare, dental, vision, and a retirement plan.

Marlborough, MA is a beautiful small city in central Massachusetts, surrounded by quaint Massachusetts towns and within a day-trip distance of the Berkshires. 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).

We are seeking talented individuals with a proven track record who are looking to help develop an industry-leading storage technology by leveraging their skills to evaluate and improve performance. We are looking for teammates who are collaborative and creative.

Each team member has an opportunity to truly impact XL Batteries, and with that mentality we need team members that are excited to work in a fast-paced startup environment that is ever changing, where no job is too big or too small, and where we strive to constantly learn and grow.

Team members in this role will work under the supervision of engineers to assemble systems for testing, collect quality data, and help achieve increasing levels of efficiency, reliability, and durability in our battery systems. An understanding of flow battery or fuel cell design and operation is a plus but not required. Applicants with prior experience in assembly are preferred. Applicants must show the ability to quickly and efficiently assemble and test new battery systems on the cell and stack level. The ideal candidate will flag challenges as they arise and propose solutions.

• Assemble and test various flow battery components and systems (follow standard operation procedures and test protocols).
• Record accurate data, analyze, and report the results.
• Interpret technical drawings and conduct quality inspections on machined components.
• Develop toolpaths based on design models and machined parts within specified tolerances, troubleshooting issues as needed.
• Engage in stack teardowns and contribute to root cause analysis efforts.
• Draft and maintain work instructions and standard operating procedures.
• Think critically about how to improve the test and assembly process with an eye to performance, reliability, durability, throughput and cost.
• Transform technical objectives into actionable work plans by establishing and managing OKRs.
• Maintain a safe work environment within a battery development laboratory.
• Manage waste streams and dispose of hazardous waste as appropriate.

• Five (5) or more years of direct experience in a technician role.
• Excellent attention to detail, cleanliness, and organization.
• Communicate technical details and feedback clearly to team members.
• Possess familiarity with industrial or laboratory work settings.
• Proficiency in MS Office; experience with SolidWorks is a plus.
• A background in electrochemistry or mechanical engineering is preferred.
• Highly motivated and self-driven individual with the ability to work independently and multitask.
• Function effectively as a collaborative team player.
• Maintain comfort with physical demands, including standing for long periods and lifting over 25 lbs.
• Ability to perform repetitive tasks with consistent accuracy.
• Must be legally authorized to work in the U.S.
• This role is a full-time and in-person position.

Application Process

• Apply through xl-batteries.breezy.hr