A close up of the battery box I have built for the transverter and the rig:
The blue battery is a EREMIT 12V 6Ah LiFePO4 battery from Funkelektronik.eu.
The schematic is very simple, only some basic protection and support for direct charging in the box. The charger I am using is the recommended 12V charger, also from Funkelektronik.