Peak Current/Amperage: The maximum current the device can deliver in a short burst to start an engine. Higher amperage (Amps or A) is needed for larger engines (e.g., diesel engines often require more amps than gasoline engines).
Cranking Amps (CA) / Cold Cranking Amps (CCA): A more practical measure of the sustained power a jump starter can deliver over a specific period and temperature (e.g., 30 seconds at 0°F for CCA), which is crucial for reliable performance, especially in cold weather.