Battery Pack Systems

About the role

We are building an integrated PSU + BBU rack power shelf that combines power conversion and solid-state battery backup into a single high-density platform for hyperscale AI data centers. This product replaces traditional separate PSU and BBU shelves with a unified architecture that leverages the unique safety and performance characteristics of solid-state battery cells.

Responsibilities

• Design the complete cell-to-pack mechanical assembly, including:Cell stackingCompression systemsElectrical interconnects (wire bonding, busbar welding, or flex circuits)Structural integration within the shared PSU + BBU enclosure
• Architect the Battery Management System (BMS) hardware topology, including:Distributed versus centralized sensingPassive versus active balancingProtection FET sizingSense line routingCommunication interfaces
• Develop and tune State-of-Charge (SOC) and State-of-Health (SOH) estimation algorithms using:Coulomb countingExtended Kalman filteringImpedance-based estimation methodsSolid-state battery electrochemistry models
• Co-develop charge and discharge profiles with Firmware Engineering, including:CC-CV charging curvesTemperature-dependent charge rate limitsFast-charge protocolsFloat and maintenance charging strategies optimized for data center duty cycles
• Design thermal interfaces between battery cells and the enclosure using:Thermal padsGap fillersHeat spreadersDedicated thermal pathways
• Conduct pack-level FMEA and battery safety analysis.
• Define and execute abuse testing protocols including:Nail penetrationCrush testingOvercharge testingExternal short-circuit testing
• Validate adapted specifically for solid-state battery behavior.
• Develop accelerated aging and life-cycle validation protocols for data center applications, including prolonged high-State-of-Charge float conditions with infrequent high-power discharge events.
• Serve as the primary liaison with the cell development team, translating pack-level requirements into cell-level specifications and feeding laboratory and field performance data back into future cell development.
• Support safety certification efforts including:UL 1973UL 9540A

Requirements

• 8+ years of experience designing battery packs or battery modules, with at least one product successfully validated through prototype testing or production.
• Hands-on Battery Management System (BMS) architecture experience. (PCB layout experience is not required, but the ability to define system topology and component selection is essential.)
• Strong battery characterization and modeling experience, including:Impedance spectroscopyCapacity fade analysisThermal characterization
• Experience with battery safety standards, particularly:UL 1973Exposure to UL 9540A strongly preferred
• Proficiency in pack-level mechanical and thermal design using:SolidWorksCreoEquivalent CAD platformsThermal simulation experience is a plus.
• Comfortable making engineering decisions while working with evolving battery cell specifications and incomplete technical data.

Qualifications

• Experience with solid-state, lithium-metal, or other next-generation battery chemistries, including research environments.
• Experience designing battery systems for:Data centersTelecom backup powerStationary energy storage
• Understanding of float-then-discharge duty cycles compared to electric vehicle cycling.
• Familiarity with electrochemical modeling tools such as:COMSOLPyBaMMAutoLionEquivalent platforms
• Knowledge of functional safety principles including:IEC 61508Equivalent standards