As one of the smallest systems around there are so many amazing things you could do with the Raspberry Pi if it was self-powered and portable. That's exactly where the PiJuice comes it！ A fully uninterruptible power supply HAT that will always keep your Raspberry Pi powered.
The revolutionary PiAnywhere technology contained in every PiJuice HAT - is the best way to take your Pi off the grid！ The on board real time clock（RTC）will let your Pi know what time it is even with no power input or internet connection. Alongside this is an integrated microcontroller（MCU）chip which will manage soft shut down functionality and a true low power deep sleep state and intelligent startup.
You will be able to always keep track of the charge levels and other info with the two built-in RGB LEDs, trigger events and scripts with the three programmable buttons and since the PiJuice will use up to just five of your GPIO pins（just power and I2C）, the rest are free to diversify your project. The stacking header allows you to continue to use your existing HATs and add-ons with the PiJuice.
Note：In the instructions, it specifies to attach a pogo pin for the wake function, but it doesn't line up with the Raspberry Pi 3B+. You can add a bodge wire for the functionality of the pin; however, the manufacturer recommends plugging in the power to the PiJuice directly, bypassing the need for the pogo pin.
Features
On board 1820mAh Lipo / LiIon battery for ～4 to 6 hours in constant use！（with support for larger Lipo Battery of 5000 or 10,000 mAH+ to last up to 24 hrs +）
Designed for the Raspberry Pi A+, B+, 2B, 3B and 3B+ but also compatible with Raspberry Pi Zero v1.3 and Raspberry Pi Zero Wireless.
Input voltage range：4.2V 10V
Output voltage：3.3V and 5V
Integrated Real Time Clock
Onboard intelligent on/off switch
Low power deep-sleep state with wake on interrupt/calendar event
Programmable multi-colored RGB led（x2）and buttons（x3）with super simple user-configurable options
Hardware watchdog timer to keep your Raspberry Pi on and working in mission-critical remote applications
Full power management API available to Raspberry Pi OS with auto shutdown capability when running low on batteries
Enhanced graphical user interface（GUI）available for easy install（via APT）
Customizable scripts for enhanced flexibility and full report of battery status
All GPIOs available via stackable header for ease of expandability and connectivity
Charge via on-board micro USB or via the Raspberry Pi micro USB（or from onboard pin headers）
Batteries can be charged from different type of sources and voltages
Replace the battery without downtime. Compatible with any single cell LiPo or LiIon battery
