Compatibility: Ensure the peak amperage is sufficient for your engine size (e.g., 600A-1500A+ for most passenger cars).
Safety: Look for features like reverse polarity protection and spark-proof technology.
Maintenance: Avoid exposing to extreme temperatures.
Capacity: High-capacity units (e.g., 60,000mAh) are available for longer-term power, such as the Anker PowerCore Reserve.