In my campervan I have a solar panel that powers a new deepcell battery. However over winter when I don't use it the Van starter battery drains and I have to charge it manually. In a fit of inspiration I thought I could charge both batteries from the solar panel.
However the van battery is used for starting the van, and I don't want the start to draw power from the deepcell. Apparently deepcells don't like heavy starting currents. So I just can't connect the batteries to each other in parallel which, if I just run two cables from the panel controller, it will do I think.
Is there some sort of splitter i can buy that can stop power going from one battery to another and yet both be charged from the panel?