Need to admit there are many easier and definitely also better solutions to control the power, and have a voltage overload detect on your solar system, but i wanted to have more control over the system, and have more data on how fast the solar panel is charging the battery.

so i started with a raspberry pi a breadboard , transistors some power mosfets, and later added a i2c lcd, ina260 i2c ics, to read the voltage, current and power.
later i also created a PCB for this and added a powersuply+under and overvoltage protection and a pcm audio out ic +3.5mm jack.