I’m not sure I understand your question but let me give it a try. I assume that the winch battery is up forward, placed there to avoid having to run a heavy set of cables to the winch. You should be able to charge them by simply connecting them to the house batteries. You should use a heavy gauge wire pair to connect this. 6 or 8 AWG is probably heavy enough. I chose to connect my winch directly to my house batteries but I had to use expensive wire, 2/0.