Batteries won't charge when on shore power

[Mark Dawson]

I am baffled....Cougar 2022 25 RDS with one solar panel and 12 v refrigerator.....batteries charge during the day with solar panel, but at night they do not charge from the converter. Tested the converter and it is putting out 13.6 volts dc. Replaced it anyway with a new tested converter...no change. Batteries do not show different voltage with shore power on or off. They do show 13.4 v when being charged by solar. All appliances and lights work till batteries drop below 11.7v. Checked circuit breaker for converter and was fine, reset it anyway. No help. Cleaned battery cables. Installed new batteries charged to 12.9v before install...they drained to 11.7v overnight. Any ideas would be greatly appreciated.

[NH_Bulldog]

Where did you check the converter output? Was it at the batteries or some point in between the batteries and the converter?

[Mark Dawson]

Originally Posted by NH_Bulldog

Where did you check the converter output? Was it at the batteries or some point in between the batteries and the converter?

At the converter output with output cables disconnected.

[chuckster57]

Do you have a battery disconnect switch? Often times the solar goes directly to the batteries.

[Mark Dawson]

Yes I have battery disconnect switch.

[NH_Bulldog]

This is where I am going; the converter has output, we know that. But the only way to know if the converter power is getting to the batteries, is to check the power at the batteries. You should have two disconnects, one for the solar which should be a black square box with a red knob in the center, and located in the front passthrough compartment. The other is the Giggy Box, which is a black rectangular box with red knob mounted to the inside of the a-frame hitch adjacent to the batteries.

First, make sure the Giggy box is on. There are positions for on, off and open (so you can remove the cover).

[Mark Dawson]

Thanks NH Bulldog. The converter power is not getting to the batteries. At night with solar not working the batteries were drained down to 11.7 by morning from 12.9 at the start of the night. Also confirmed the batteries tested 11.7 on my multimeter in the morning. Ideas for next steps?

[chuckster57]

Originally Posted by Mark Dawson

Thanks NH Bulldog. The converter power is not getting to the batteries. At night with solar not working the batteries were drained down to 11.7 by morning from 12.9 at the start of the night. Also confirmed the batteries tested 11.7 on my multimeter in the morning. Ideas for next steps?

Follow the leads from the battery, when you reach the first connection, test on both sides. There may be a circuit breaker that has failed.

[NH_Bulldog]

Originally Posted by Mark Dawson

Thanks NH Bulldog. The converter power is not getting to the batteries. At night with solar not working the batteries were drained down to 11.7 by morning from 12.9 at the start of the night. Also confirmed the batteries tested 11.7 on my multimeter in the morning. Ideas for next steps?

Have you found the Giggy box and checked that the disconnect is in the operational position? Here is a good video from Keystone:

https://www.youtube.com/watch?v=Lo7_8vwVMxU

[Mark Dawson]

Yes the Giggy box is in the on position, and to confirm that I can see the lights in the trailer cabin work.

[Mark Dawson]

Thanks chuckster57...The first connections are inside the Giggy box... how are the solar charger wires connected to the batteries. ie how to know the Solar wires from the converter wires inside the Giggy box?

[chuckster57]

I haven’t had to open one up, so I can’t say but they may be labeled.

[Mark Dawson]

Originally Posted by NH_Bulldog

This is where I am going; the converter has output, we know that. But the only way to know if the converter power is getting to the batteries, is to check the power at the batteries. You should have two disconnects, one for the solar which should be a black square box with a red knob in the center, and located in the front passthrough compartment. The other is the Giggy Box, which is a black rectangular box with red knob mounted to the inside of the a-frame hitch adjacent to the batteries.

First, make sure the Giggy box is on. There are positions for on, off and open(so you can remove the cover).

Hi NH Bulldog...Here is picture of the solar controller. It does not have a red knob. How can I turn the solar off so I can concentrate on the converter issue?

[NH_Bulldog]

I have a 5th wheel so my setup is a little different. You should have a disconnect located somewhere that looks like the one in the upper right in my picture.

[spicercars]

Welcome from northern MN. Good luck with your charging issue.

[adm1949]

I've been experiencing a similar issue. At first I thought it was the converter and had an RV tech check it out. He found the converter to be okay. It puts out 13.6v to the batteries. I keep my trailer in an enclosed workshop and have 50amp power. I have no problems when on 50amp power in the workshop. I do, however, have problems when I am in a campground with shore power. Everything works fine until the solar is no longer charging the batteries in the evening. At that point, my batteries start draining. I think the problem may be with the solar controller. It is an MPPT 50/15. It doesn't seem to be switching from solar back to shore power. I found an entry in another forum that suggested turning the power off to the solar controller but there doesn't seem to be way to do that with the 25RDS. When the solar has stopped charging I did try disconnecting the batteries at the giggy box for a few minutes and then turning it back on. Not sure why this worked but it seemed to reset something(solar controller?) and my trailer was back on shore power. I'm getting ready to do some boondocking at the end of this month and I really need to solve this. I'm thinking about replacing the solar controller. Anyone have some input?

[NH_Bulldog]

The solar controller is not connected to the converter and is not a one or the other type of setup. The solar controller does just that, it controls solar from the panels to the batteries, that’s it. It does not “talk” to your converter.

I would suggest resetting the controller to factory settings and then going through the setup process from the beginning. Make sure you have the correct battery chemistry type and size selected, and make sure your solar charging voltage is correct. It is possible that your solar controller is charging the batteries to a higher state than your converter, and your converter is “thinking” the batteries are fully charged so it doesn’t engage to charge the batteries.

For example, if the solar controller is using a lithium profile, it will charge to 14.6 volts, but if your converter is using a lead-acid profile, 13.6 volts is fully charged. So until the batteries drop below the set point, it will not kick in and charge the batteries.

Right now it is dark here, I am plugged in and my solar controller is off (no sunlight). The batteries are at 13.7 volts and the battery remaining time is an infinity symbol.

[adm1949]

The solar charges the batteries to 13.6 but when the sun goes down the batteries start dropping quickly even though I'm plugged in to the 50 amp shore power. When I disconnect the batteries at the giggy box and wait a few minutes before connecting them again it resets (something). At any rate that works when plugged in to shore power. I'm getting ready to boondock for a week and am concerned about it and not sure what to do. I will go through the reset of the controller and see if that helps. Thanks.

[NH_Bulldog]

Try this; while connected to shore power, turn the Giggy Box to the Off/Open position (cutting battery power to the camper). Then see if you can operate the slides, leveling jacks, lights, etc. If your converter is working correctly, you should still have full power to all the 12v DC in the camper (slides, levelers/stabilizers, lights, etc.) in addition to the 120v AC items (microwave, Air conditioner, etc.).

[adm1949]

Thanks again. Actually I did that the other night and left it in the "off" position all night. Everything worked great.