Safely testing no power.

[Russellvh]

2022 FR Wildcat 5th wheel.
I’m curious how long I could, safely, go Boondocking if I wanted to. What is a safe way to test this. I can test while at a park and could unplug from shore power and truck. Do I just watch the on/off light on the refrigerator? Just use normal lighting until they start going out? What if I unplug in the morning and everything is still running at bedtime?
Only 3rd time out, bought brand new came with 2 deep cell batteries. Don’t want to damage anything but curious.
Obviously inexperienced newbie.

[Reverse_snowbird]

I'm assuming you mean that you want to preserve battery life.
It all depends on how long you want to boondock and you can test this in your driveway if it's level or at a park. Just don't plug in.
First, make certain that your batteries are completely charged then...
Decrease your electricity use by not using the lights by using battery operated lanterns. Put frozen water bottles in the fridge and freezer to minimize the temperature going down and turning on.
Buy a battery monitor so that you can tell what the battery usage is and don't let them get too low or it will decrease their life.

Or don't do any of the above except do use a battery monitor and see how long you can boondock.
You do need battery power to operate the brakes on that rig, so don't let them go dead if you're going to tow it from a park.

[TacomaJoe]

Congrats on your decision to test the rig. Step two now is to learn your system. Do you have an inverter that takes the 12V battery power and makes 120VAC? Is your refrigerator a residential (120VAC only) or absorption (120VAC or LP)? Your water heater is probably 120VAC or LP, do you know how to control which heat source it uses? Do you have some sort of battery level meter (not sure what came built in)? You need to ID the batteries to determine how much capacity you have to work with.

A shunt power meter is a valuble tool for testing. A volt meter can tell you the voltage of the battery but unless you are checking a battery that is just sitting (not in use) your reading won't be too much of a level indicator.

I encourage you to learn your system. Best done before you need to know the system, sitting in a cold dark rig in the middle of the night.

[NavyLCDR]

Very basically, unplug the shore power cord (or turn off the main breaker), disconnect the 7-pin cable from the tow vehicle. Measure the voltage at the batteries with a voltmeter. Once you hit 12.0 volts, that is as far as you can safely discharge the batteries without doing damage to them. NOTE: to get a true reading, the batteries need to be disconnected from all loads for several hours - but the voltage with load applied to the batteries will always be lower - so it errs on the safe side.

[loyda]

Look into solar to help charge battery