Enhance your power management with this versatile Lithium Battery Expansion Board featuring two distinct working modes for both outdoor and indoor use. Designed for reliable performance, it serves as a portable power supply when used outdoors and as an uninterruptible power supply (UPS) indoors, delivering stable and efficient power with built-in safety features for ultimate protection. Key Features: · Dual Working Modes: Functions as an outdoor portable power supply powered solely by a 3.7V 4000mAh lithium battery and as an indoor UPS power supply when connected to a 5V 2A power adapter via Micro-USB. · Outdoor Portable Power Supply: Provides a maximum external output capacity of 5.1V 2.5A, ideal for powering devices on the go without relying on external power sources. · Indoor UPS Power Supply: Offers continuous power support with an external USB-A interface delivering up to 5.1V 3A when connected to a standard 5V 2A power adapter, ensuring uninterrupted device operation. · Intelligent LED Indicators: Equipped with a 4+2 LED display system for clear charging, discharging status, and battery power level visibility, allowing easy monitoring at a glance. · Comprehensive Protection System: Integrated overcurrent and overdischarge protection safeguards the motherboard and connected devices from damage, enhancing reliability and safety. · Self-Recovery Fuse for External Output: Protects connected devices, such as Raspberry Pi, from damage caused by external short circuits by automatically fusing and restoring output when the load is removed. · PMU Over-Discharge Protection: Automatically cuts off the 5V output when the lithium battery voltage drops below 2.8V to prevent battery damage from over-discharge. Specifications: · Battery Type: 1 x 3.7V 4000mAh Lithium Battery · Package Weight: Approx. 122g (4.3oz) · Output Voltage: 5.1V · Max External Power Output (Outdoor Mode): 2.5A · Max USB-A Output Current (Indoor UPS Mode): 3A Package Includes: · 1 x Lithium Battery Expansion Board · 1 x Lithium Battery · 1 x Set of Installation Accessories This Lithium Battery Expansion Board is an essential power solution combining portability, stability, and safety for powering various devices in multiple scenarios. Whether you need a reliable outdoor power source or a seamless indoor UPS backup, this board provides efficient power management with advanced protection features for worry-free operation.