Thread: Split Charge system : How big a fuse do I need?

I am in the process of installing some LED lights and a Diesel heater in my Camper,so I thought it was a good time to install a split charge system.

My question is:How big a fuse do I need between the first battery and the Voltage Sensitve Relay? The one I am installing is rated for 125 Amps,should a 100 Amp fuse do the job?

I will install a couple of USB ports and probably LED flood lighting around the outside of the box too,not that its really go alot to do with that circuit.