The BATTERY is a definite requirement when towing your trailer. This is DOT STATE SAFETY REQUIREMENT for any trailer that is equipped with electric brakes.
If your run away trailer were the cause of damages or worse loss of life and it was determined that you did not have a working 12VDC battery to operate the DOT safety feature then your insurance might not go in your favor.
Another good reason is that the trailers are really designed with many 12VDC items that either run off of the 120VDC to 12VDC Converter when on Shore Power and 12VDC batteries only when off the power grid.
If the 120VAC lost power at the campground then you would be in the dark. With the good working battery still working you would only loss the 120VAC appliances in this case. Your ceiling lights and many other 12VDC items would continue to operate from your trailer battery.
Also if your trailer has a slide-out it sometimes really needs the battery to aide the converter DC Voltage to make the slide operate when on shore power. I also have had to hookup a jumper cable from my truck start battery a couple of times to make my trailer slide-out work good when I didn't have shore power connected.
Everything just works better having the trailer battery working normal.
Roy Ken
