** What is this?** This is like a solar powerbank designed for IoT applications and other uses. 1 to 3 18650 Li-Ion cells can be used for increased capacity (also available connection for an external battery placed in parallel with the onboard ones or on its own). 5-18Voc solar panels (10W is recommended) can be used to charge ther install battery. It has two output rails, one 5V3A and another 3.3V2A. They both turn on and their combined output is 15W.

** In detail** The charger is MPPT with adjustable Vmpp via the onboard trimmer potentiometer. It is set to charge the battery with 1.7Amax There is reverse polarity/backfeed protection for the solar panel and reverse polarity indication. Each battery onboard and the external connection for battery are protected by a fuse. There is also battery protection for over-discharge, over-charging, short circuit, over current & reverse polarity insertion. The output turns on and off using the onboard push button (or an external push-button). If battery protection kicks in due to over-discharging, when external power is next applied, the output will also turn on. There are measurement outputs for battery & solar panel voltage which are enabled when output turns on and are both set to a max 3.3V via voltage dividers. This allows battery and solar panel monitoring from an MCU.