Explain what happened in order
A slow start, warning and accessory failure might share a cause or be separate concerns. Describe which happened first, the time the vehicle was parked and anything unusual that preceded the change.
Measurements need a relevant context
Battery condition, connections and available charging data may form part of the investigation. The correct checks depend on the vehicle and its control systems. One low reading alone does not settle why the condition occurred.
Bring the history you know
Mention the battery replacement date if available, recent jump starts, electrical work and accessories added to the vehicle. Follow model-specific instructions for unfamiliar systems. Avoid disconnecting parts merely to see how the car reacts.
Agree on the first electrical check
Ask what the initial assessment includes and which finding would prompt a recommendation for further work. Arrange suitable delivery if the vehicle cannot be driven safely. When discussing results, keep the original symptom in view.