How many times have you taken your motorhome out of storage and found the batteries are completely dead? You went through your pre storage checklist and made sure lights were off, circuit breakers were off and still your batteries come up dead. Why is this happening?
Almost every motorhome or RV has what is called a parasitic draw from their 12 volt electrical system. Usually what causes the parasitic draw will be the radio, LP gas detector or the refrigerator. Your inverter, even shut off can draw a small amount of current. After a few weeks all these draws can drain your battery bank to its knees. This is why you want to install a battery cut off switch and avoid the parasitic draw.
There are several battery switches that offer various functions and come in a variety of sizes. The most common switch is a cut off switch that goes between the battery and the positive connection. Another type has a key that can be removed when shut off to avoid someone turning it back on or being able to start your motorhome if used on the starter battery. If you are willing to pay a little more you can get a switch that will disconnect between two battery banks and ensure that all 12 volt devices are not getting to the battery.
If you will be installing a cut off switch, it is recommended to place it on the positive side of your DC circuit. Most cut off switches can be found at your local RV parts store or automotive store.