WARN Quick connect for charging

[StateParked]

The previous owner of my truck (Nissan Titan 4x4 LE w. factory tow package) has installed a WARN quick connect to the rear of the truck that is switched under the hood. I intend to purchase a Passport 238MLWE or Bullet 2070BH in near future. I understand that pin # 4 of the trucks trailer hook up will attempt to charge the batteries when hooked up and driving, but this is limited by the length and gauge of the wire to the # 4 pin. Can i take advantage of the heavy gauge wire already "plumbed" into my vehicle to charge the batteries when moving?
Anyone have any other ideas for utilizing this WARN quick connect with a travel trailer?

[Yak]

The thing to keep in mind is that the alternator should only be used to maintain a battery, not charge a low battery.