Describe the platform
Share the application, available battery envelope, mounting approach and intended production stage. Reference drawings or a mechanical model can help clarify fit constraints.
Quantify the electrical profile
Include nominal and operating voltage, energy target, continuous load, peak load, duty cycle and charging conditions. If a value is unknown, mark it as open rather than estimating.
Include the environment and interfaces
Temperature, vibration, ingress exposure, communications, protection behavior and target-market requirements can change the architecture and validation plan. Bring these topics into the brief early.