I have been thinking about running a 4AWG back to a second battery bank mounted in the truck bed to re-charge two 150AH 12VDC batteries in parallel from a smart relay setup using the truck alternator. I already have a 4AWG cable from my truck start battery connection to an additional 12VDC Blue Sea 12VDC Distribution Panel under the rear seat of my truck where my two way radios are located. This 4AWG Cable is fused for 60AMP service...
This setup will also have manual battery switches which will also use a 2-cond cable going back to the trailer 300AH battery setup and give me a 600AH battery setup when camping. I will use the trailer on-board converter/charger to recharge both battery banks when in camping mode.
I have come up what looks like a good layout for controlling this setup. The only think I have not determined yet is the capacity of my truck alternator. My alternator will have to be large enough to add the two additional 150AH batteries to its charging circuit which I doubt a standard size truck alternator setup will handle. Certainly don't want to blow up my truck alternator.
My PLAN B is just use my 2KW generator and B&D VEC1093DBD portable smart mode battery charger to re-charge my 300AH battery bank in the truck bed.
I need the batteries to be in the truck for weight reasons more than anything else in my case... The few times I would be using the batteries in the truck by itself will be few when on my EMERGENCY RADIO nets and events etc... Not a problem using the generator/portable charger setup to charge the truck bed batteries for three hours every morning during breakfast.
Having a large enough ALTERNATOR for the extra batteries added to it in your case may be something you will need to look into as well...
Roy Ken
