Originally Posted by spartacus
I am new to towing, and I have a question about the power running to the 7 pin connector. It seems that the power is live to the battery and not the ignition, so if (assuming I turn off every light, etc. in the camper) I leave it plugged in will it drain the tow vehicle battery? What if the camper battery is fully charged, will it still take power from the tow vehicle battery?
There's not a yes or no answer, it all depends.
When connected in the manner you describe any power consumption devices in the trailer will draw from both batteries, any devices in the tow will draw from both batteries. With nothing on in the trailer except the propane
detector it will take several days to run both batteries down. A stop for lunch or even over night is NOT going to have much effect.
FYI, my factory tow package connects the battery in the tow directly to the battery in the trailer when the trailer is plugged into the tow. My standard procedure is to disconnect the trailer when camping, or a quick overnight sleep. I leave it connected for all rest stops including meal brakes
Hope this helps a bit.