what are the main duties of Starter Battery on vehicle?

Electrically, the battery is intended to supply and generate:

• The power required for cold cranking
• The power/energy required when the alternator is not able to supply the consumer needs
• The energy required by consumers during non-rotating engine phases (engine off)
• The voltage thresholds to guaranty the quality of the 12V board net

Thermally, the car battery shall allow the vehicles’ engine to be started. The battery should cover a temperature range between -30°C and +75°C.

Three vehicle situations can be considered:

• Vehicle in the roadway: maximum temperature in the range [50 – 55°C]
• Vehicle in the city (high traffic): maximum temperature in the range [60 – 65°C]
• Vehicle in severe usage (e.g., mountain driving) or key off: maximum temperature being 75°C (time-limited to 20 minutes)