Truck 12VDC to Trailer Battery - Really Needed?

[scottandgaye]

So, this is kind of an interesting question. I have three peripherals in my coach (a rear windows mounted dashcam, a TPMS repeater and a Garmin rear mounted camera) that require 12 volts. Now, the Garmin is "technically" supposed to be powered off of the reverse light, but I prefer to have it always powered and be able to select it at will from the unit.

So, my question is, is the 12 VDC from the truck to the battery really all that necessary for folks that have several other means of charging their batteries? We boondock a lot, but I have Honda generators, solar and shore power for those occasions when we pull into a campground for the night while on the road. So, my batteries are almost always fully charged in the morning. All I run in the coach while travelling is the fridge on propane (requires 12 VDC for the control board). There are a couple of other items that are probably minor parasitic loads, but they are in the milliamp range.

I'm giving serious thought to removing the 12 VDC that goes from the truck to the coach batteries and using it to solely power my peripherals. That way, there is no drain on my coach batteries when parked AND, unlike running them to the lights on the coach, I don't have to remember to always turn on my truck lights for things to work. I have considered wiring it all together to a common SPST switch, but there is always the possibility that I will forget to either turn it on or off. I am trying to make it foolproof (but you know the saying about that).

So, has anyone diverted their truck > trailer 12 VDC and utilized it for something else? Just wondering if there is a major downside that I am missing here. By they way, I have a total of 8 6 VDC GC2 golf cart batteries in a parallel / series configuration, giving me a total of about 800 AH (400 usable).

If I missed something or you need additional info that I did not provide, please let me know and I will be happy to answer. I appreciate the time that folks take to read and answer these posts!

Scott

[scottandgaye]

I like that idea! For the time being, I have just removed the supply to the batteries, but I may very well design that and implement it. Hadn't even thought about something like that. Thanks!

Scott

[KD4UPL]

Hook the loads to the RV battery with a voltage controlled switch set to around 13 volts. When the batteries are charging it will be on, when not charging it will be off.

[scottandgaye]

I could do that, just come off of the battery through a fuse and run everything. But, I HATE parasitic loads on my coach, especially when it is stored. We have power at the storage, but in the winter, that is hit or miss. I prefer to just make it a dumbed down as possible, so that I just can't forget it or mess it up!

Scott

[time2roll]

With that battery and solar, the truck to trailer connection makes little to no effective difference on charging. No reason to rewire anything. Just pull power from the trailer battery as needed.

[JRscooby]

Normal 7 wire connection; Ground, Power, Brakes, Rt turn, Left turn, Running lights, and Aux
I think I would use the Aux