Im wiring up a DC to DC charger does the output wires from the charger need to connect directly to my aux battery or can I connect them to some battery posts I have set up that are connected to the aux battery?. I have my solar charge controller, a fuse box and inverter connected to these posts. Also is it better to have the fuse on the dc to dc charger wires closer to the batteries or the charger. Lastly im using the victron 12/12/18 model with 8 awg wire a 25 amp fuse is good? the length is around 7 ft. Thank you