Not charging batteries in shore power?

[afried]

We recently bought a 2018 Flying Cloud 25FBQ. The dealer installed new batteries, Northern AGM. We’re plugged into shore power, a home 110V/15 amp circuit with a Power Watchdog surge suppressor supplies by the dealer. Power is coming to the trailer as indicated by the lights on the suppressor and plug and power to the trailer plugs. However the battery voltage keeps dropping a few tenths every few hours: 12.5 to 12.3 with no loads except the parasitic ones, 12.0 to 11.8 with just trailer lights and the main vent fans. All the 110 circuit breakers are energized. Haven’t pulled the 12v fuses, but there’s no red lights on the converter panel. What’s going on? Shouldn’t the voltage be increasing or at least not dropping on shore power? I’m handy with a voltmeter. How can I tell if the converter is working? Maybe this is a newbie question, but thanks!

[Daquenzer]

Originally Posted by afried

We recently bought a 2018 Flying Cloud 25FBQ. The dealer installed new batteries, Northern AGM. We’re plugged into shore power, a home 110V/15 amp circuit with a Power Watchdog surge suppressor supplies by the dealer. Power is coming to the trailer as indicated by the lights on the suppressor and plug and power to the trailer plugs. However the battery voltage keeps dropping a few tenths every few hours: 12.5 to 12.3 with no loads except the parasitic ones, 12.0 to 11.8 with just trailer lights and the main vent fans. All the 110 circuit breakers are energized. Haven’t pulled the 12v fuses, but there’s no red lights on the converter panel. What’s going on? Shouldn’t the voltage be increasing or at least not dropping on shore power? I’m handy with a voltmeter. How can I tell if the converter is working? Maybe this is a newbie question, but thanks!

Make sure that you turn the switch to “in use.” So in other words if you unplug from shore power you won’t get any power. Then switch to “in use” and you are on battery power. Now plug in to shore power. You don’t have to do this, but it is one way to make sure the switch is “in use.” If it is not in the “in use” mode your batteries will not charge.

Another option you might try if this doesn’t work for some reason, is get some trickle chargers and run them to the batteries from the outside outlet on the trailer. But this is only if the other doesn’t work. By the way, when storing always put a trickle charger on the batteries. Some old inverters over charge from what I’ve heard. It’s just a safer method with a trickle charger that hold a constant voltage on your batteries.

Obviously the biggest problem with a dead battery is your power jack won’t work.

[BayouBiker]

The voltage should be north of 13.1 V with shore power and the converter functioning.

First off disconnect the batteries before their resting (no load) voltage drops below 11.9 V or get an external charger, low voltage is very hard on batteries.

1. There are no 12VDC fuses involved so don't look there for the issue.
2. Are you sure You are getting shore power to the power Center or are the circuits running from the inverter? Is the refrigerator, the microwave and the television operating?
3. Has the converter ever worked to maintain a charge?

The converter manual describes how to test the converter if you are able to confirm it is getting 120V. If you have a single AC then your power center and converter are integrated

[TG Twinkie]

Check the reverse polarity fuses on the converter.
They will be 30 amp or larger.
Did the dealer remove them when replacing the batteries. Did the dealer blow the fuses.
What kind of dealer does not check their work?

[sixweeds]

I know this is an old post, but it is a new problem to me. My 2019 25' Airstream International Serenity FBT. It has a Zamp solar controller. On shore power it is not charging. It charges with solar, though. In reading the responses, first question I have is where is the converter? I didn't get a manual or any documents for the controller, unless it is the same thing as the Zamp solar controller. Where are the fuses to it? On the fuse panel, it says there is a 30amp main, and next to that is 20amp AC and next to that is the 20amp converter. I don't see any other fuses that are labeled converter. There is another one labeled inverter. And under the front street side storage compartment, there are some wires that protrude into the storage compartment, but most of the electrical stuff appears to be under the street side bed paneling. Are there any fuses there? There are also fuses attached to the battery. A big clear one on the positive post, and an inline yellow fuse holder leading to the other battery positive. The battery disconnect is "On" and I have a red light. The power cord has a red light on it as well. And on the Zamp control panel, the red "power" light is flashing. Any help would be appreciated!