A starter for the urgent desires. So, com board is ready and was done with M3 heat inserts in mind. 

As there is currently no idea of where it would commonly fit this is not the final solution. I for my part will fit it into a gridfinity box, but this isn't viable for 280 Ah batteries. So, its mainly the sketch that you can make use of.

For the likes with thingiverse, hello Andy, i uploaded the stl that can be cut into whatever shape is needed. 

The display will be next and I guess I omit the board itself. I probably upload the dimensions as a picture. oh, and I need to design a button.

Please keep coming with ideas as how it should be modified.