What's draining my RV battery even when everything is off?
When my RV is boondocked and we go away for the day I sometimes find the battery is dead when we return. What's draining my battery while my rig is boondocked and vacant?
We will assume that your battery is in good condition. A bad battery cannot be fully charged so will drain much faster than a good one. Did you forget to turn off all the lights? I never remember to turn off the outside 'porch' light! Also, it's easy to forget a light inside a storage compartment or closet. But you've checked all those, right? Did you leave the furnace on?
There are some less obvious sources of power drain.
Your RV refrigerator, even running on propane if it has an electronic controller
An 'auto start' water heater... it has an electronic controller
The LP gas leak detector The CO2 detector
The clock on your radio
Individually, these all have very small power requirements but, added together, they can be a significant drain on your battery. There is not much you can do about this problem short of getting a larger battery or disconnecting the battery.
Nearly every motorhome and travel trailer has a cutoff switch somewhere so you can turn off all RV battery power to the RV. Just shut it off and then your battery can't run down (assuming it is in good condition). If your rig doesn't have a disconnect switch one can easily be installed.
At home or wherever you have power you can connect a small "trickle" charger or solar panel to the RV batteries while the rig is stored to compensate for the drain.
Your may also want to read: How Long Will My RV Battery Provide Power?