The 1-Avel y PiJuice HAT is the best way to take your Pi off the grid. The real time clock on board will let your Pi know what time it is even with no power input or internet connection. Alongside this is an integrated microcontroller chip which will manage soft shut down functionality and a true low power deep sleep state and intelligent start up. You will be able to always keep track of the charge levels and other info with the two built in tri coloured RGB LEDs.

Soft shutdown function
Raspberry Pi HAT compatible layout
Replace the battery without downtime
Enhanced graphical user interface
Low power sleep state function