House battery charging & discharging

Read "12volt side of life"

Get a cheap digital multimeter/voltmeter. Set it on the 20 volt DC range. With RV plugged into shore power, touch the red probe to the positive house battery terminal and the black one to the negative house battery terminal. You should read 13.6 volts DC if your converter/charger device is working. With RV unplugged from shore power, house battery should read 13.6 volts DC for a while then voltage will slowly drop with lights on, etc. If your batteries are old or if they have been left discharged/dead a number of times or if they have been overcharged and fluid "boiled out" ,they may need replacement. Of course all the connections to the battery must be kept clean and making good electrical contact at the battery terminals. I just replaced the two original house batteries ( two 6-volt batteries in series for 12+ volts) and noticed that the converter/charger was not charging. I ordered a new and much better converter.(Progressive Dynamics PD9245C) Recommend you take your rig to a trusted RV repair place if you are not able to do troubleshooting and replacements yourself. Batteries are very heavy and cost $100 or more apiece, new converter costs around $165, plus tax, and labor for installation.

If you have a voltmeter measure the battery voltage at various times. That way you can tell if it is getting fully charged. Depending on your converter, it could require much more than 5 hours to fully charge the battery.

You can probably find a convenient place to measure the voltage at the power distribution panel. Make sure you are measuring the 12 volts, not the generator output of 120V. Usually the 12v power uses fuses, the 120v uses circuit breakers.

Hi Wendy,

Welcome.

How old is the existing battery?

What size is it in amp-hours?

What is the temperature outside?

What converter is in the RV to charge the battery?

Welcome to RV.NET.
Many RV's will not make it through the night on house batteries. Mine included. The fan takes a lot of amps to run.
There are ways to fix this.
Try lowering temperature in MH so furnace will not run as often. I set ours a 60 and use lots of blankets.
Add more batteries.
Get a propane heater that does not have a fan.
My fix was a Auto Generator Start (AGS). Works great on all but propane generators.
This requires that you are parked where a generator can be run anytime.