Fully remote position for a US start up. We are looking for a Battery Systems Engineer to work with a US sodium battery startup on a remote basis. You will have the deep technical expertise and the commercial mindset required to design and quote against advanced Energy Storage Systems (ESS) RFQs across a wide range of customer applications. With a strong backlog of inbound demand, this role is critical to scaling our ability to deliver accurate, timely system designs and proposals. As a key member of our engineering team, you will work closely with the founders to tailor solutions for customers across various industries and scales from compact starter batteries to complex, high-voltage, behind-the-meter (BTM) energy systems. Applications You'll Support Include: 12V Starter Battery Packs - for automotive, marine, and industrial engines 24V to 48V Battery Packs - for forklifts, mining vehicles, airport ground support, and other heavy equipment 48V Systems - for residential, light industrial, and virtual power plant (VPP) applications Department of Defense (DoD) Microgrids - mobile or stationary systems for tactical energy resilience Auxiliary Power Units (APUs) - integrated battery-based power sources for remote operations Telecom Backup Power - ensuring network uptime in rural and off-grid sites Remote Environmental Monitoring - powering instrumentation in harsh or isolated environments Data Center Backup and Grid Edge Storage - maintaining uptime and providing grid support 600V High-Voltage Packs - for industrial-scale applications and EV charging station buffering Large-Scale BTM Systems - multi-megawatt-hour storage for commercial/industrial energy management Key Responsibilities Design complete battery energy storage solutions tailored to customer use cases Perform detailed component selection, sizing, and system configuration Create technical documentation including block diagrams, SLDs, and bill of materials Develop accurate, cost-effective project quotes in response to RFQs Analyze load data and application requirements to optimize performance and ROI Support customer discussions as a technical subject matter expert Stay current on evolving standards (UL, NEC, NFPA, IEEE) and emerging technologies Required Qualifications Experience designing and quoting ESS for a variety of industrial and commercial applications Proven experience with lithium-ion (especially LFP), BMS systems, and inverter/PCS integration Deep understanding of energy use cases and battery sizing methodologies Proficiency in design tools Familiarity with grid interconnection standards, safety compliance, and thermal management Show more Show less