2023 Swift 20D house batteries not charging on shore power

[JayNJ]

Hi guys!

I am new to the forum and new to RV ownership. My wife and I bought a 2023 Swift 20D in Dec 2024 and we're on our first camping trip and I'm seeing some behavior that seems wrong to me - or I could very well be doing something wrong.

When on shore power, the house batteries are not charging. At first, I saw that the inverter was disabled. I believe this should be set to "pass through" mode to allow it to charge the batteries - is this correct? However, even on "pass through", they slowly lose charge to the point that the Firefly control center shows them at ~11.2 V or so and the indicator turns red. The only thing running on 12V is the Norcold fridge which also gets a red power button and the series of flashing lights translates to under voltage (we are also running the Truma heater on electric - but I understand this to use 120V directly and its fine). Also, the inverter "button" will have a red dot which I take to mean there is a fault?

What I've observed is that if I start the engine - which I understand lets the chassis alternator charge the house batteries, it'll automatically go into pass through mode and the house batteries will go up to ~13.3 V with everything going green. Once I turn off the van engine, it stays in "pass through" but slowly goes down over time to the low 11 V range. I've checked the circuit breaker for the inverter and convert and cycled them off and on. Today we heard a relatively loud thump come from underneath the "house" towards the back while I was running the engine to charge the batteries - not sure if that was related but was somewhat worriesome.

Any advice or anything I should/can check? Is there something I'm missing/not understanding? I called the dealership and they said it is likely an issue they need to troubleshoot with the inverter/charger, but I'm 100s of miles away so just seeing if there is something I can check or should avoid - given the noise we heard and some warnings I've seen about letting the batteries discharge too much.

Much appreciated & TIA,

Jay

 

[Iowagriz]

I assume you are at a campground? If so, double check to make sure their power pole is functioning pproperly.Are you using a surge protector at the pile and does it show all is ok? If so, when connected my 2023 gets a blue light at the end of the shore power cable.

Lastly, does the microwave clock turn on? If so, then you are getting power via shore power and it might be the converter.

The inverter shouldn't need to be touched or changed, it will do it automatically.

Edit to add...the Truma could be running on battery and not shore power, thus the rapid draw down. Again, microwave clock should be a better sign of shore power.

 

[JayNJ]

Thanks for the quick reply. Yea we’re at a campground in Ga.

Also yes, I have a power watchdog and it shows everything is fine (attached screenshot from app). Microwave is up and works - wife heated some lunch just a few hours ago.

Around the area of the house batteries underneath and in front of the rear axle I hear a clicking sound that is very infrequent. This is also where we heard the loud thump while the engine was running. After running the engine for a while and turning it off it seemed we heard that every ten minutes or so. Then after a bit it stopped.

Worried/wondering if there is any safety issue here or if it is just an inconvenience for 12v appliances?

Thanks again.

 

[Iowagriz]

Unusual for sure....bummer....probably the converter (i think that is what it is called) that take the shore power to charge the batteries. You could probably save power by running propane for heat. Maybe try the generator for recharging the batteries?

 

[JayNJ]

Will try the generator and report back. Thanks

 

[Schiel1]

Check the converter. That is what Charges the house batteries

 

[JayNJ]

Sorry for the delay in responding here. I tested the generator, but it is not charging the batteries either. At this point it does seem that I have a bad converter as suggested since when on shore power there appears to be no 12 VDC in the system beyond what the batteries supply - which slowly drain down. I will be setting up a service visit w/ the dealer once my trip is over. In the meantime, the chassis alternator does charge the house batteries so I simply run the van for ~30 minutes twice a day and we've been getting by for now. I may get a 12V charger to connect to them, but they seem to be very difficult to reach underneath the unit centered just in front of the rear axle.

Thanks all!

 

[Schiel1]

Sorry for the delay in responding here. I tested the generator, but it is not charging the batteries either. At this point it does seem that I have a bad converter as suggested since when on shore power there appears to be no 12 VDC in the system beyond what the batteries supply - which slowly drain down. I will be setting up a service visit w/ the dealer once my trip is over. In the meantime, the chassis alternator does charge the house batteries so I simply run the van for ~30 minutes twice a day and we've been getting by for now. I may get a 12V charger to connect to them, but they seem to be very difficult to reach underneath the unit centered just in front of the rear axle.

Thanks all!

If your not in warranty. It is very simple to change out the converter.
Even if your in warranty. Depending on your circumstances, you could still do it. You only the then converter not the whole panel.

 

[mrmom]

Just a shot in the dark, but have you checked for either a fuse or circuit breaker on the line between the converter and the batteries?

 

[Schiel1]

Just a shot in the dark, but have you checked for either a fuse or circuit breaker on the line between the converter and the batteries?

He stated that the house batteries are being charged by the chassis so i would guess nothing tripped.

 

[JayNJ]

I've reset all breakers (there is one for the converter) and I hear a clicking sound (like a switch/relay) after charging it up w/ the chassis - so guessing it is the converter itself. @Schiel1 - it is under warranty - was bought late last year - so I'll let the dealer handle it. If it comes to it, my father is an electrician so I"ll get it changed out one way or another.

Thanks!