Questions about Solar usage and Battery expectations

tnave863

I have a 2019 XL Boondock Edge with the factory solar package added. This is the solar that is the flexible panels and all wiring/controllers are hidden. I recently discovered how to connect to the solar charger controller via Blue Tooth.

Since discovering this, I placed my trailer so that it would be getting full days in the sun. The app shows that there has been 14KwH of total generated (I assume that's what it meant). I reset the current and since have seen 0 (zero) movement in the numbers.

Yesterday, I turned on the fan and cooler to test how long it would run. When I started, the Phone app showed I had 12.46V in the battery. There was approx. 4 hours of direct sunlight remaining in the day. The voltage was about 11V when I went to bed last night. This morning (~19 hours later) the voltage had dropped to 10.2V. The frig had shut off due to low voltage (manual says 10.4), fan was still running. The sun had not come up enough before I left this morning to be considered direct sunlight.

My questions are what should my expectations be regarding the solar and the battery?
How long should the battery power the cooler/fan?
Should I see movement in the solar controller via the app?
Does the solar not function when the battery is full, even though in direct sunlight?
Is something wrong with my solar or battery?

beaky

the solar is simply a small trickle charger , it will charge the battery whether the battery is on or off. the biggest drain on power are fans and plugged in appliances. we pre cool the fridge for 12 hours by plugging in the trailer the night before the trip and turning the battery on. if its not screaming hot we turn the fridge off at night as it is a very effective cooler in its own right. that 10.2v level is pretty low so you might contact NuCamp. a bigger , deeper charge battery is an option. on cold nights we just turn the battery off at night.

Sharon_is_SAM

What charge controller are you using? What was the battery state of charge as 12.46 volts in a rested battery is not a full battery.

A battery that is almost full is harder to stuff the last amount of amps into it and especially under limited sun will take time. The SCC also will reduce the current. Not knowing what the other measured parameters are, it sounds like you had a combination of excess amp consumption and not enough sunlight and time.

What size battery do you have in amp hrs?
19 hours of running the cooler and fan will not be supported by a small battery.

tnave863

The charge controller is the Victron SmartSolar MPPT 75/10. According to others the Panels are made by Sun Flare and are 111W. That is the only information I have on them, and none was provided by NuCamp.

According to the app the battery state is listed as off. I have never seen it in any other state, since I discovered the Victron App.
I will have to check the battery size when I get home.

Mostly I'm expecting to see some charging coming from the PVs, but the history shows 0, even though I have the panels pretty much in direct sunlight for most of the day. I want to understand the limitations and manage my expectations for using them.

Sharon_is_SAM

When you get home, give us a screen shot. Hope you turned the battery off.

Fourman110

The battery installed on my 2018 was really undersized. Turned out to be much more of a car battery and I could watch the meter drop when I was using the fan. If you see it rated in CCA (cold cranking amps) I’d suspect that’s at least part of the problem. WilliamA likely has sage advice posted somewhere on this forum.

tnave863

So, I started digging around and got to the Victron Solar controller. It's on the back side of the back wall of the TV cabinet. I suspected the wire from the solar panel was not connected. I found that it was connected, but there was a inline fuse holder that was empty! I popped in a 20A (it said 30A max) and boom, everything came online. It's later in the day and I don't have full sun, but I'm still getting 30-40 watts coming out.

WilliamA

40 watts is a lot of power. That's a good thing. 40w/12v=3.33 amps. Even as you say, with it being late and not ideal solar angle that's good output. Consider that a good, well regulated battery charger won't push a battery past 5 amps for very long. It's going to drop down to 3-4 amps on the back end. Any higher for too long and it will swell the plates in the battery. Don't forget that a setup like this can't be compared to an automobile which puts out big (30-50A) amps because cars are consuming a ton of juice to run. So what's left to maintain the car's battery is nominal. In a system like your trailer, a good usage calculation must take in both the charge needs of the battery AND the current usage. So if the system is putting out 80 watts but you have the fridge and fans on, that 80 watt number may not be getting much free energy back to the battery. There is also a significant line loss in connections, switches, shunts (especially those) and the wire itself. It all sounds really intimidating but it's really quite straightforward. For usage numbers, just use the consumption data on the device. The fridge and ceiling fan have that info on the data plate. It's probably going to make me sound like a 6th grade science teacher, but familiarize yourself with the calculation for changing watts to amps etc. It's super easy and can always be googled. If you do, there are about 10 wattage/amperage calculators that will show up. For example, you said your controller indicated between 30-40 watts. Let's call that 25 watts. Just divide the wattage by the battery's current voltage: 25 divided by 12.2 volts =2.04 amps. That's nearly enough to run the fridge on a cool day, minus the extra 50% start-up amperage. So if you need 4 amps or so to charge the battery, 5 or 6 amps to run the fridge and fan and add in 10-15% for loss (I'm being optimistic. It's probably closer to 20% that means you'll need at minimum of 150 watts. That calculation looks like this: 10 amps needed X battery voltage 12.5 = 125 watts + 15% (line loss) or about 19 watts = 134 watts minimum for the full charge cycle. Let's call that 8 hours. You know you need 6 amps for the fridge and fan, so any less than 84 watts charging from the solar panels and you're actually losing. With all that, you can see that on an average, you'll need to consistantly have to produce 100 watts to run devices + what you need to run the charger. I did this math on the fly so it may not be exact, but you get the idea.
It's also really important to remember that the lower the battery's voltage, the higher the wattage will need to be.
Whew!!
There it is.
WilliamA

rich67

@tnave863 said:
So, I started digging around and got to the Victron Solar controller. It's on the back side of the back wall of the TV cabinet. I suspected the wire from the solar panel was not connected. I found that it was connected, but there was a inline fuse holder that was empty! I popped in a 20A (it said 30A max) and boom, everything came online. It's later in the day and I don't have full sun, but I'm still getting 30-40 watts coming out.

How did you access it? Via the white cover in the back of the cabinet? Can you post some pictures of where it is mounted/how you access the controller? Thanks!

Chaverim

Yes please send photos. I asked nucamp for details so I can install solar and they aren’t replying. This is the 3rd time I used their website to ask questions and got no answer.

I don’t know you need a new battery though like suggested earlier. I have used my fridge all weekend on my battery and still had 11.8V when I started heading home.

tnave863

I don't have pictures, and I'm not going to take it out again, unless I have to. But it's really easy.
Make sure all the power is off first, just in case... Open the cabinet behind the TV. On the back wall there's two plastic caps and the AC plug. The caps just pop off. Under those are screws (size S2). Remove them. You might need to unplug the AC. I removed the screws for the AC plug, but I don't think that was necessary. The back panel should pull out, but it's tight. The solar controller is on the back of this panel.

mgreen2

We just got home after 11 days in Panam City, Florida helping with hurricane cleanup. No electricity or water in the area. Used our Renogy solar suitcase to keep the Norcold fridge, lights, fan, etc running 24x7. Battery never a problem. Filled the T@G water tank and brought 2 five gallon containers of water to refill. Very happy with how everything worked. It as so humid the solar panels were covered with condensation every morning so I kept a towel handy to wipe them off. You could see the charging increase immediately after cleaning them.

Michigan_Mike

You want to keep an eye on and monitor your battery voltage. Granted the voltage does and will drop under load when the fan and fridge are running, but you shouldn't let the battery voltage stay below 12 volts for any long duration, as over time, this will damage the cells of the battery. As noted above by William and mgreen2, the solar is a good thing but may not be keeping up with your consumption. The frig will suck up a lot as will the fan motor and VCR, so with time, frequency of use and familiarity (monitoring your system voltage) you will become more acutely aware of what you can use and the best means of balancing your energy needs and usage. There's definitely a learning curve that occurs here and asking questions as you have done here is a great way to find out what others are doing and how they conserve energy.

Sharon_is_SAM

Some people turn the frig off at night to conserve power.

Cbusguy

If it's that big a deal put in a second battery or replace it with a higher amp hour unit.

I think my tag will end up with 300 amp hours of lipofe battery's and I am looking hard at a methanol fuel cell. We will see how the bonuses roll this year.

The flexible roof top solar is less than ideal and not a huge fan of the way the factory is installing them. We will see in the next couple of years how they hold up.....if I spend that kind of money they better last more than a couple of years.

Sparrow

Norcold suggested to bring the fridge freezer up to temp 12 hrs before and keep it there as the battery will only hold the temp but not charge the fridge so I don't know about shutting it completely off. I would turn the fans off first I think. The Nordold fridge draws 4.3 amps.

rich67

I don't see why the fan would need to run constantly, either. If you camp during times of cooler weather, you can kick it outside when it's warmer, and run the fan on low at night if it's even needed. Cracking windows is all you need to do. Lights and the fridge (I second the people who say shut the fridge off at night) should keep power consumption to a minimum.

JamesDow

From my experience, the Norcold (NRF-30) is a very efficient unit. I always pre-chill the unit and usually place a couple bottles of frozen Gatorade. I usually set temp near 32 and the last time out camping, I unintentionally froze some items. That was with outside temp over 105 degrees. I use a Renogy solar suitcase w/Voyager controller and so far I have not dropped below 12.1 volts on my battery.

SueBHunny

@JamesDow said:
From my experience, the Norcold (NRF-30) is a very efficient unit. I always pre-chill the unit and usually place a couple bottles of frozen Gatorade. I usually set temp near 32 and the last time out camping, I unintentionally froze some items. That was with outside temp over 105 degrees. I use a Renogy solar suitcase w/Voyager controller and so far I have not dropped below 12.1 volts on my battery.

This is what I am hoping for. I just got the Renogy solar suitcase and I'm going to give it a driveway test run this weekend. I've had no trouble running the fantastic fan at night while we sleep, but my hope is that with the addition of solar I'll be able to run the Norcold and still run the fan at night and keep the battery at a good level. Fingers crossed....

JamesDow

SueB, Hope your driveway test was a success. I ran some opposite type tests with my litlle Baja Propane generator (Model: BAi911LP). I got about 1.8 hours of full on AC usage out of a 1lb Coleman style canister. I refill my canisters, so that is about $.49 worth of propane. Calculating that out using the 20lb propane tanke on the T@B, that would be over 65 hours of AC full on usage. - - -

SueBHunny

Life happened this weekend, so my solar test got bumped. I'm going to hook things up tonight and let it go with just the Norcold running. If that goes well, tomorrow night I'll run the fan on low as well. All the fingers are crossed. I'd really like to be able to use my Norcold this weekend.

Sharon_is_SAM

Pre-cool the Norcold on 110v first.

SueBHunny

@Sharon_is_SAM said:
Pre-cool the Norcold on 110v first.

Already done!

SueBHunny

Solar test day one: The Norcold stayed cold overnight and the battery is holding strong. Today I'm hoping the solar panels will charge the battery up and tonight I'll try the Norcold/fantastic fan combo. Fingers crossed...

bayje

what kind of solar system are you using?

SueBHunny

I'm using a Renogy Solar Suitcase. 100 Watt. After my battery drain issue I replaced my battery. We've been golden since then. The solar gives us just enough added kick to meet our Norcold and Fantastic Fan needs!

HikinMike

Im looking at a Renogy 200W suitcase as I am wanting to charge my battery while running the Dometic Cooler and the fan.

willbingham1

I have a 50 watt Renogy panel mounted on top of my aluminum tongue box replacement and while unplugged in Mesa Verde RV site for 3 days, I was able to keep up with the Norcold overnight with a simple deep cycle wet Interstate 100 amp battery. Norcold was set for 32 degrees because it has about a 5 degree swing in its cooling cycle. I got down to about 12.3 volts in the morning, but the charge during the day with PWM renogy controller still did the trick. I did one afternoon before supper run the Yamaha generator for about 1 hour and half to run my 110 toaster oven (I hate making generator noise in campground unless necessary) and that next morning I was at 12.4 volts before solar charging began. Pleased with the results. Recently have added a portable 100 watt suitcase by Renogy to add to the stable and will plug it in the Zamp plug on side of tongue box and still have available the 50 watt with its own controller on top of tongue box. Have yet to use this system but and I am sure it will work well and provide even when my 50 watt panel is in the shade enough juice for battery. Later will go to either AGM or gel 100 amp battery when Interstate starts showing some wear. I am on the second season of camping with this battery. Picture of current system below. Bill

rchawla

I have a 2021 T@G and on the containing the battery is jack to plug-in external solar. I also have a hardwired PV panel on the roof with a Victron MPPT 75/10 controller. Can I use my external suitcase solar (with built-in charge controller) IN ADDITION to the built-in solar and charge controller?

Sharon_is_SAM

I just answered your question on the new discussion you started here: https://teardrop-trailers.vanillacommunity.com/discussion/1344/2021-t-g-can-i-use-built-in-solar-and-external-suitcase-solar-with-its-own-controller#latest

Bottom line - yes.