A battery lock for 4 battery systems is designed to secure multiple vehicle batteries inside a single protective frame. It is commonly used on trucks and commercial vehicles where four batteries are mounted together and exposed. This type of setup prevents theft by blocking easy access to the batteries and holding them firmly in place. When paired with a strong battery anti-theft device design, it also helps reduce vibration damage and accidental loosening during long drives, making it useful for both security and durability in daily operations.