Note: The B2 battery, when magnetically attached to the base, only outputs power once the USB cable is connected. Specially Designed Enhancement: The BOBOVR P4S is a purpose-built enhancement kit for Pico 4 Ultra, featuring a detachable battery, reinforced head support, and an improved top strap for unparalleled comfort and extended playtime. Seamless Power Management: Utilizing BOBOVR's signature magnetic hot-swap technology, the B2 battery (5200mAh) can be effortlessly replaced mid-session. The battery activates upon connection, ensuring efficient power management and uninterrupted VR experiences. Optimized Power Extension: The high-capacity 5200mAh B2 battery increases your Pico 4 Ultra's battery life by approximately 65%. For optimal performance, we recommend charging your Pico 4 Ultra to above 50% before using it with the B2 battery. Superior Comfort Engineering: The P4S boasts an enlarged, ultra-soft back support, crafted with premium memory foam and wrapped in supple leather. This ergonomic design significantly enhances comfort during extended VR sessions. Versatile Comfort Options: Choose between two distinct pad materials for personalized comfort. The skin-friendly PU leather pad offers luxurious feel, while the non-slip silicone honeycomb pad provides maximum grip, catering to various preferences and VR scenarios.