Charging and Ignition Integration Under Cold-Start Stress

🚧 Under construction.

This paper documents an electrical integration lesson learned while modernizing the electrical system of a 1983 BMW R80ST (custom harness + modern control electronics + lithium battery + upgraded charging/ignition components).

It is written as a systems-engineering case study: observed symptoms, boundary conditions, hypotheses, tests, and mitigations. Where manufacturer behavior is relevant, it is treated neutrally and respectfully; conclusions are limited to what the data support.

Planned contents

• Symptom timeline and boundary conditions (cold soak, low SOC, repeated start attempts)
• Standby power budget and measurement method (bench supply vs BMS obscuring current)
• Load deltas from lighting policy decisions (e.g., headlight default behavior)
• Thermal boundary discussion for regulator/rectifier placement under tank at idle
• Thermal characterization plan and acceptance criteria (trend-based, then numeric once limits are known)
• Mitigation strategy and operational guidance for extreme environments (Prudhoe Bay / Ushuaia)

Status

• Drafting: active
• Test program: pending controlled runs
• Public PDF: not yet published