Low solar output on a new 2026 Navion 24R

[HRYSER]

We have been twice camping (boondocking) in our new Navion thus far. After arriving at our camp-spot we had a 99% - 100% charged Lithionics 320 Ah battery. However, after three days, the battery charge went down to 50%. The M'home was both times perfectly exposed to unrestricted sunlight at about 8500 ft elevation and < 10% rH. I was quite surprised about this unexpected charge drop or lack of restoring the energy with the rooftop mounted two 120 Watt (240W) solar panels.
I compared it to the camper-trailer we had before we purchased this Navion. The trailer's solar system (2x100W solar) was always fully charged by the evenings, using the same heavy AC draws like our four coffees in the mornings, 12V refrigerator and slideout. By trying to troubleshoot the Navion's solar system, I drained the battery to the 85% charge level and put the coach into the full, completely unobstr

ucted sun. As the sun stood almost straight above us, I checked the solar status on the coach's WinnebagoConnect panel (see picture). Please let me know in case I misinterpret the screen. But what I think it means is that 9W are being drawn from the battery and the panels/charger are producing 11W. Despite the fact that the charge is larger than the draw, it still calls is "discharging". Then, I went to the gear garage to check the charger/controller. The PV voltage was 25.1V. I want to point out that earlier this morning I washed the solar panels to make sure that the sun's energy is fully used.

Is it wrong for me to expect to see a "Solar Source" value of about 150 to 200Watt? What do you think isn't working as it should? With a minimal power draw of 9W, I would expect the battery to be fully restored by the afternoon.

Am looking forward to receiving your thoughts. Thanks and have a nice weekend

 

[Sparky19053]

The fancy display is nice but dig in to your charge controller and check what battery type it is set up for. Most likely your charge controller is made by Zamp, not the greatest. 240 watts of solar is not a lot power but in idea sunlight you should be seeing closer to 150 ~180 watts coming off the panels. Plan on upgrading the Zamp to a Victron MPPT 100/30 or 50. You'll have a fun time learning but upgrading the solar can be fun. We have the 2021VNavion with a Victron MPPT-100/50 connected to 780 watts of solar wired in series. Here in PA its easy to harvest 1.5KW or more per day. Remember, charge controller will only give the bettery what it thinks it needs so if the bettery type is wrong its not going to properly charge your battery.

 

[HRYSER]

Many thanks Sparky for your advice. Before I retired for the night I tried to reboot the controller by running all power sources down, letting it rest for a half an hour and powered it up again. This resulted in having now 0W charging power for the battery...! This was not what I wanted to see but I decided to let it be over night and return this morning with a fresh mind. So, at 7 AM I went to the motorhome and checked the WinnebagoConnect Energy screen. To my surprise and with the sun barely above the horizon and light clouds, the display showed "Charging" at 125 t0 127W !!!!!!!!!! Somehow, the system needed the to rest just as much as I did. Hey, I am not going to interfere now and hope the system will get the charge level up above 150W when the sun is above us and returns to normal working order. By the way, the controller is a Xantrex model 710-3024-01. Thanks again for your help

 

[creativepart]

There have been 2026 and 2027 T, R and D owners that have commented elsewhere about poor charging performance from the solar panels. The solar charge controller is a Xantrex MPPT controller. You can find it in the large tech bay behind the big black metal panel on the passenger side of the RV's gear garage.

If you remove that panel you can scroll through the settings on the screen on the controller. Some folks have mentioned incorrect settings and you can change them there.

Here's a photo of the equipment behind that panel and you can see the solar charge controller.By the way, all that stuff back there is the Winnebago Connect controllers. It's a combination of stuff from Silver Leaf, CZone and ATC. There's even some marine NEMA2000 network and RV-C stuff back there.

 

[Sparky19053]

For the life of me I don't understand why the charge controllers are mounted such a distance from the batteries they are charging. In our 2021V I just re-routed the cabling from the battery to the charge controller. The original path was from the controller above the frig, down to under the passenger side bunk. Then passed under the body to the drivers side where it then travels forward to the wiring compartment under the drivers seat. Finally crosses to the passenger side where it connects to the circuit breaker panel under the passenger seat. Oh and yes the battery parameters were set wrong in the Zamp charge controller.

 

[RV_Lee]

My solar will only go down to small watts like that when the battery is 100% charged. As someone else said make sure the the system is set to lithium. At 84% it should still be taking as much solar as it can get.

That said 240 watts isnt much. I'd want another 200 watt panel up there

I had 300 watts for 1 year and it wasn't enough. I didn't even have a 12v fridge and I have a bigger battery. From sundown to sunrise I would lose around 10%-15% a day that the small solar couldn't recover. Your numbers are similar - but make sure everything is working first

 

[HRYSER]

Many thanks Lee

I feel as you do, there should be more juice coming from the solar system to the battery.
For example, I drove the M'home for about 45minutes today to charge the starter battery. Then, this morning, I had some interior lights and the inverter on to put a load on the coach battery. The charge level dropped down to 74% and the solar power was at 35W, total "usage" at 151W and the message "discharging". When I turned the inverter off, the Usage went down to 86W, the charge level still at 74%, the message "discharging" and the soler power at 35W.

- Shouldn't the solar power be grater?
- Or does the charge level be much lower until the controller provides more juice?

I tried to use the WinnebagoConnect to check the controller's settings for the selected battery type however, It didn't work saying that the controller is connected to the Winnebago system and therefore can't communicate separately. I am a little stuck. Would it help if I took the black panel in the gear-garage off and try to work on the controller setting directly? Or will the system say again that the controller is communicating directly with the onboard management system (which doesn't provide the info needed)?

Thank you all for your valuable information.

 

[Sparky19053]

You should be able to access the battery settings thru the Xanetrax charge controller. While I don't have first hand experience with the winniebago connect its my understanding this is collecting the information only, Not controlling it. While this is a great site you may want to check on FB for a group that offers more technical information, Facebook
BTW the battery settings fpr the charge controller in our 2021 were wrong from the dealer.

 

[klook]

You must check the mppt for the settings, everything else is a waste of time until it is set right. Then, like others have said, you need more solar capacity. Rule of thumb is 200 watts for every 100 ah of battery. You are under watted...lol. Over paneling is better then under paneling. You can get more juice before and after peak time. Even one of the expensive fold out suitcase rigs will help a bunch. You can point it for maximum effect.

 

[creativepart]

You should be able to access the battery settings thru the Xanetrax charge controller.

To see the settings he’ll need to remove the panel I mentioned to access the screen on the Controller. Connect shows an output voltage and not much else. And, you can’t control the solar charge controller settings from within the Connect system.

As to his expectations about his solar output I think it’s possible that the OP’s expectations are perhaps optimistic. But hey, while I have the same exact model I don’t rely on solar to charge my battery so I don’t really pay much attention to the real world numbers that come from my solar setup.

 

[creativepart]

Shouldn't the solar power be grater?
- Or does the charge level be much lower until the controller provides more juice?

Hryser , where are you, what time of day, what’s the cloud cover? How about direction of the RV and trees and obstructions? All these things obviously play a part in your solar productivity.

People tend to expect X amount of solar charging if the sun is out. But a charge controller will control the amount of charge you are feeding your battery based on all these variables and the current state of charge on the battery.

It’s really not possible for us to tell if you have an issue or just the wrong perception of what you should be seeing based on all these variables involved.

 

[RV_Lee]

If its randomly going from 150 watts to 11 watts of solar in direct sun (when battery isn't charged) its probably an issue with the solar controller. I also wouldn't worry about what its using or discharging, just focus on how reliably its producing power at the moment

 

[HRYSER]

Thank you all for your great analysis and suggestions. As to the sun exposure, I live in the South-West corner of Colorado, in the heart of an awful drought. The coach has absolutely full sun without any trees or building nearby. At 7400 feet altitude, the air is pure, no smog NO HUMIDITY. Thus, I have to learn how to cycle through the settings directly on the controller, once I can find the info on how to do that.

 

[creativepart]

Here's the solar charge controller's Owner's Manual PDF. You can make changes and monitor the output via the screen on the front of the Controller.

They do make a hard wired Remote Display, unfortunately unlike the Inverter Remote this does not have a bluetooth feature and phone app. It costs $65 and you simply plug it into the Controller. and then you can mount the display anywhere you wish, so you don't have to keep removing that metal panel in your Gear Garage.

Xantrex 710-0010 MPPT Remote Panel

Xantrex Solar 710-0010 MPPT Remote Panel | DonRowe.com

The Xantrex Solar 710-0010 MPPT Remote Panel provides remote monitoring and setting of Xantrex Solar MPPT Charge Controller parameters. Displays real-time system data including PV array voltage, amps, and watt-hours, as well as battery voltage and temperature from a remote location. Includes...

www.donrowe.com

It is available on Amazon as well, but it's $80 on Amazon.

 

[HRYSER]

Thanks bunches Creativepart. I will study it to work the controller.