I've got a 7 pin, but Expanda with 150L fridge and battery comes with 12 pin plug. I want to be able to charge battery down the track with portable solar panels. Should I get Jayco to change the 12 pin to a 7 pin and keep the battery wires separate with an Anderson plug and then install an Anderson plug on my car, or should I change my car over to a 12 pin and then cut into the battery wires on drawbar and put an Anderson plug connection in so that I can discontect and charge from portable solar panels that way?