Cell Test Engineer

Zipline•South San Francisco, CA

About The Position

Zipline builds autonomous delivery aircraft and ground systems that operate daily in demanding field environments. The performance, reliability, and safety of our aircraft begin at the battery cell. As a Cell Test Engineer, you will develop the test systems, methodologies, and data that characterize cell performance, validate new technologies, and improve the safety and reliability of our battery systems. The Battery & Power Electronics team is responsible for delivering power throughout the aircraft—from individual cells to complete battery packs and power distribution systems. You will design and execute experiments that evaluate electrical performance, thermal behavior, degradation, abuse tolerance, and lifetime across multiple cell technologies, enabling critical engineering and sourcing decisions. This role is open to engineers at all levels. Responsibilities and technical scope will be matched to experience, with opportunities to grow from owning individual test programs to defining cell validation strategy across multiple aircraft platforms.

Requirements

Experience in battery cell engineering, electrochemical testing, energy storage systems, or validation engineering appropriate to your career level.
Experience developing or executing battery cell characterization, life testing, abuse testing, or reliability testing.
Strong understanding of lithium-ion battery fundamentals including cell chemistry, degradation mechanisms, thermal behavior, and electrical performance.
Experience operating battery cyclers, environmental chambers, DAQ systems, thermal instrumentation, and laboratory equipment.
Experience developing automated test software or data analysis tools using Python, MATLAB, LabVIEW, or equivalent platforms.
Ability to design experiments using statistical methods and interpret large experimental datasets.
Familiarity with battery safety standards and abuse testing methodologies.
Experience with instrumentation including thermocouples, RTDs, current and voltage measurement, impedance measurement, and thermal imaging.
Strong written and verbal communication skills with the ability to communicate technical findings and influence engineering decisions.

Responsibilities

Own end-to-end development of cell validation programs from requirements → experiment design → execution → analysis → engineering recommendations → continuous improvement.
Develop and execute cell characterization programs evaluating capacity, impedance, power capability, efficiency, thermal behavior, and aging performance.
Design validation plans covering electrical, thermal, environmental, mechanical, and abuse testing to qualify cells for drone applications.
Design experiments that evaluate cycle life, calendar aging, fast charging, temperature performance, storage conditions, and operational limits.
Develop custom fixtures, instrumentation, wiring, thermal interfaces, and automation supporting repeatable, high-throughput cell testing.
Operate and improve battery cyclers, environmental chambers, thermal measurement systems, DAQ equipment, and laboratory instrumentation.
Develop automated test scripts, data processing pipelines, and reporting tools using Python, MATLAB, LabVIEW, or equivalent software.
Analyze large experimental datasets to identify degradation mechanisms, performance trends, failure modes, and opportunities for optimization.
Perform post-test teardown inspections and correlate electrical performance with mechanical and thermal observations.
Support abuse testing including crush, penetration, thermal runaway propagation, overcharge, short circuit, vibration, shock, and environmental exposure.
Work closely with battery design, systems engineering, reliability, manufacturing, and suppliers to define validation plans and support product development decisions.
Develop laboratory procedures, calibration methods, safety documentation, and standardized test methodologies that improve repeatability and engineering efficiency.
Support supplier qualification, incoming cell validation, technology benchmarking, and root cause investigations involving field-return hardware.