Waveshare PoE UPS Base Board for Raspberry Pi CM4, Gigabit Ethernet, Dual HDMI, Quad USB2.0 Features 1. PoE UPS Base For CM4: Uninterruptible power supply, powering the CM4 while recharging 2. Connecting With Compute Module 4: Standard CM4 socket and color-coded Raspberry Pi 40PIN GPIO header. Suitable For Compute Module 4 LiteEMMC Series Module 3. Uninterruptible Power: It is able to charge the batteries and provide power output for the system at the same time from external power supply. Automatically switch over to batteries output if external power supply is unavailable, keeps the system running without any trouble 4. Multi Power Supply Options: - Three external power supply options: USB interface, wide voltage DC, and PoE - When connected to the external power supply, the system will be powered and the battery will be charged at the same time, and the battery will be in a disconnected status after being fully charged, so as to avoid battery life damaging caused by frequently charging and discharging - When the external power supply is insufficient, the battery will provide power output together with the external power supply at the same time to ensure system normal operation - When the external power supply is connected, the system will keep running normally even when the battery fails or is taken out. When the external power supply is disconnected, it will automatically switch over to batteries output without interrupting the system operation 5. Safe And Stable Circuit Design: Protection circuits for over chargedischarge, over current, short circuit, and reverse-proof along with the standalone resettable fuse for each battery, more safe and stable 6. Real Time Monitoring: Monitoring the batteries voltage, current, power, and remaining capacity via I2C. (When the voltage dips too low, it is possible to save files properly and then shutdown the system by software, to avoid any data loss) Note: The 18650 batteries are not included Specifications 1. CM4 socket: Suitable for all