Solar info spinning head

Aubrey

We are about to start our first full season of T@B 400 towing and I have been reading and watching video on solar options until my head spins.
We have a 2018 with one 235Ah battery.
I have read a lot about the suitcase panels, controllers, extension wires etc..

We want to go a few days if needed off grid with normal usage of our 12v tv, Jensen stereo, 12v fridge (the "efficient" type) and some lights. Occasional water pump too.

Would we be happy with a 200w Renogy portable with controller? Some say the wire terminals are a bit flimsy. 
Do we need the 200w panel with this battery? Or is it just better?

Are the limits on extension wires based on the distance between the battery and the controller? Or between any of the components?

I know the info is out there, but I am not confident

Petroffski

Aubrey-
Nobody has chimed in so I'll give it a shot.  I'll need to assume that your battery is up to snuff otherwise nothing I say here is valid. 

I have the '19 400 that came with two 6v AGM batteries adding up to 224AH (assuming THEY are up to snuff!), similar to your proposed setup, which makes this easy. It also came with 2 - 100W roof panels. So... on paper, your hypotheticals make perfect sense as it matches closely to what NuCamp intended. 

Personally I wouldn't use any panels that add up to substantially less than 200W. While things might work with less than 200W there is the whole "sleeping well at night" thing that needs to be considered. IF you have sun on the panels all day, every day, then what you're considering would be fine. If you have clouds for several days or you park in the shade, then things could get sketchy. So many variables...

I now have 220W solar on the roof (darn hailstorms!) and another 110W portable panel that I use to chase the sun, on its own controller, that we use if we park in the trees. This has worked for us in all conditions that we've encountered. We don't use the TV but everything else you mentioned is spot on.

If I remember correctly I used 10AWG - 25' cables for our portable panel using disconnects on both sides of the trailer. I used 12AWG between the controller and the batteries because the battery is just a few feet from the controller.

I hope this helps you-
Peter

pthomas745

Your 235 ah battery can provide approximately 50 to 60 percent of those amp hours.  So, about 112 to 135 amp hours. Some people say you can draw them down to even 80 percent, providing 180 amp hours.   Your "efficient" fridge is the NR 751 (I think) that has an average draw---when it is running--- of only 3.2 amp hours. It does not run all the time.  There are many threads here with owners with this battery/fridge combo being very comfortable for a couple of days, even without solar, and multiple days with decent sun.

For two days: your fridge "might" use 60 amps over 48 hours.  The trailer "parasitic drain" (the things that can't be turned off) are usually reported at about 8 amps for the 400.  Two days, the "drains" and the fridge are 76 of your amp hours. (These are real ballpark guesses, probably a bit high).  Even if you tried for those two days....you would have to work really, really hard to use up the other 36 amp hours (112-76=36) left over.  The trailers are pretty efficient.  Watching a movie might take 3 or 4 amps.  The lights hardly use any.  The pump only uses power when running. 

Add even a 100 watt panel (with good sun, of course) and during the daytime the fridge power use and parasitic drain would be "free".......the solar could keep up with quite a lot of the fridge use, and possibly recharge the battery entirely.  The only time the fridge would be drawing down the battery would be at night.

Trying to make sense of the solar YouTube pages is a frustrating experience.  Don't let the bafflegab get you down.  It is much easier than people make it.  You aren't wiring up a nuclear power plant, just a 225 amp hour battery.  Many owners on the Forums have easily made their solar setups work.  Some are really pretty and installed nicely.  Some, like mine, are not.  But, the very first minute I took my old massive panel, attached to my battered old controller, and connected it to my 320 battery with alligator clamps, I was charging my battery.   Any decent solar kit/suitcase (Renogy, etc) will work. The only "hard" part is the connection to the battery, sometimes that can be confusing.  Many many owners have done it, so just ask for help when the time comes.  This thread has a comment by "Skwhee" that covers the fridge/solar usage that might be helpful. 

https://tab-rv.vanillacommunity.com/discussion/comment/105149/#Comment_105149

PS: Don't go too far down the rabbit hole on wire gauges and distances.  (Unless you are going out 60 feet or something!)   The best idea on that is: it is better to have the solar controller close to the battery.  However, many suitcase setups have the controller attached to the panels.  Still, I have yet to hear of anyone complain that the solar suitcases aren't working. 

pthomas745

Travels with Delaney also did a fridge test.

https://www.youtube.com/watch?v=saNx9s-gDWY

Aubrey

Pthomas745, that is one custom order response! You have laid out clearly the simplicity of the system. I was WAY too deep into the videos, most of which are for huge rigs. 
I watched a bunch of Travels with Delaney last fall to familiarize us with our T@B and then winterize. Great stuff.
Looks like a 100w with a 20' cord should
be adequate. Would 200w be overkill? 

Denny16

Aubrey, we also have a 2018 TaB400 with the single 200 AH AGM battery, and we use 200-watt solar panels with it, which charges the battery back up during the day, from the overnight load discharge.  The rule of thumb with solar panel charging, is 100-watts per 100-amps of battery, so for your rig, 200-watts is what you want.  

You can also get nice portable solar panels that do not have a built in regulator, and get a Victron MPPT 75/15 (which is what nüCamp is using) and put the MPPT between the solar panels and battery (mount the MPPT inside the rear cargo area close to the battery), then use a cord coming out the cargo door, to eliminate having to wire and drill an external connector, to start with, and see how it goes…
cheers

Aubrey

I see the extension cables on amazon state "connect between panels and controller", our T@B 400 has no factory solar. So if an extension cable is planned on being used sounds like I should buy a suitcase without a controller, or unmount the renogy controller and move it closer to the battery.
   I see so many varying reviews on controllers it is hard to trust them all. And on the zamp website they claim a 90w panel is good for a small RV, they must mean REALLY small.
   

Aubrey

I see my question about the controller was answered by Pthomas745.
At the $340 amazon price (200w with controller) it seems like a good gamble to take, maybe move the PWM controller into cargo and use extensions. If we need more I guess we could consider the upgrade to a MPPT later)..
Its nice to have the forum to fumble my way through.

VictoriaP

@Aubrey One thing I’ve not seen mentioned here is your location. If you’re camping in the desert Southwest, where sunlight is plentiful year round, a 100 watt panel for every 100 amp hours of battery, and a PWM controller, will be a decent setup. Conversely, if you camp in northern half of the US, anywhere in Canada, during spring/fall/winter, or under moderate to heavy tree cover? You may want more solar wattage, and you definitely want the greater efficiency of an MPPT controller.

This article has some details on the differences if you scroll down a bit. https://www.renogy.com/blog/what-is-the-difference-between-mppt-and-pwm-charge-controllers/

qhumberd

So depending on the location of your battery (we have the 2019, no solar on roof, with 2 6 V batteries under a cover on the passenger side ) you will have to see what access you already have to your battery. In mine it is wired to a distribution stud with 2 nuts. If you have that then it should be easy to connect the solar panel output to the terminals. In mine a dealer connected there and ran a wire to the driver side wall and put in an SAE plug, which works with most of the solar suitcases, as long as you confirm the polarity. These have been termed Zamp connectors for another brand of panels. Here is a picture of my setup under the bed. It appears rotated 90 deg for some reason but I think you can see the orientation with the covered wires at the top of pic going to door where battery cutoff switch is located and the lower covered wires installed by dealer to driver wall and the SAE connector. This way you will not need to remove the battery cover. hope this helps

Aubrey

I should mention the 2018 T@B 400 we have is using one 200ah battery and has a "zamp" plug installed from nucamp. Battery is under bed in cargo and the battery terminals are accessible. We live in Ohio but hope to do some travelling mostly south and west but who knows!?
I assume I could mount the Renogy PWM controller in the cargo and either use the battery clamps or run a wire out the cargo hatch with the polarity adapter into the zamp port, then plug in the panels to the controller (or the extension cables then panels).
We just want to stay topped off with AGM 12v power and maybe use a small inverter on occasion for laptop and such.

Aubrey

Maybe mount the PWM controller to the inside of the cargo door upside-down so that when the cargo door is opened it would be oriented for use?

GatorEgg

try to narrow down goal.  Trailer mounted? Suitcase solar?  Maybe tow vehicle mounted?
My preference is suitcase since I like to park trailer in shadiest sites.  I can move suitcase panels wear they work best.  Then determine size needed.  There’s many “amp hr worksheets” out there.  Bro baby even some from members here.

Aubrey

Definitely going portable.

pthomas745

Solar controllers all look the same...because basically they all are the same. (At least, the inexpensive ones are.)  Most likely, they all come from the same Chinese factory.    Shop for warranties and returns.  Look at the Windy Nation controllers.  They have good value, and I had one that worked for many years until I dropped it a couple of times.  The company sells cables and other solar equipment.  I've bought all my solar extension cables from them.    Recently I bought an MPPT controller from Epever.  They have controllers all the way from small PWM's to large controllers designed for large multipanel installations.  I bought a cheap MPPT from them about 5 years ago that finally just failed a few months ago. 

This is a nice example of a slightly "upgraded" PWM with a small display.  Windy Nation has one like this.  The display is a nice little feature.

https://www.amazon.com/EPEVER-Controller-Working-Regulator-Powerful/dp/B081GRRSPK/ref=psdc_2236627011_t3_B0936Y1SGB?th=1

And, edit.  You probably should go with a 20 amp controller if you plan a 200 watt setup. This one is a little pricier, but it is MPPT, and with a little MT50 dongle it is even programmable if you ever get to lithiums.  But, at this price...you might as well go one more step up and grab a Victron for the advantage of the Victron App and battery voltage monitoring.

https://www.amazon.com/EPEVER-Controller-Working-Regulator-Batteries/dp/B081GSCYWP?ref_=ast_sto_dp&th=1

Sharon_is_SAM

@Aubrey - the 200 watt portable panels are large and heavy.  You may want to consider 2 separate 100 watt panels.  Easier to store for travel, lighter weight.  If a panel gets damaged, you still have the other one.  I recommend 30 feet of marine cable for your extensions.  Very flexible and easy to store.

Horigan

@Aubrey
Given that you have a Zamp plug already installed and connected to your battery, you should consider a portable panel(s) with integrated controller as a simpler solution.  Zamp panels would plug right in, or any other panel with the plug replaced with a Zamp plug.  You should also consider getting a cable lock for your portable panel(s), depending on where you camp...

Denny16

Yes, if you go with a setup like Renogy’s portable suit panels (2@100-watt panels) just use the factory Zamp plug and leave the PWM controller on the panels, this setup works fine for up to 25-foot cable run, no real advantage to moving it to the TaB, and the integrated controllers are not easy to remove.  As it comes, you only have on cable coming from the two panels to plug into thenTaB.  

I believe, the Renogy two panel setups, wire the two solar panels to the controller, and then the controller single output cable goes to the battery.  With a MPPT controller like the a Victron, (the 15 amp controller is designed for 200 watt solar panels), you hook up the panels in parallel or series, with a single lead from the panels to the controller, so back to a single hookup cable.

Here is what the 2018 TaB400 single AGM battery setup looks like, with plywood cover removed:

Access to battery terminals is available from middle under bd compartment.
Getting his heavy battery out is another story…
Cheers

NorthIsUp

As we camp and try figure out what we're missing that would make the journey safer and more comfortable. First thing we bought was a Honda eu2200 generator even before the trailer showed up. Good investment. We also realized early on that a Micro-Air Easy Start would help signicantly with the a/c startup.  Makes a/c startup at night super quiet. For our 3rd season, additional solar to supplement the factory system was decided upon. I was parked for several days at a National Park in the no-generator allowed area in the fall facing the wrong way to get direct sunlight. After that, picked up a heavy Z-Amp 180 watt panel to supplement what we had so that I could have solar whenever we needed. I think you need to camp and see what's needed as you go. I think the next step is to replace the 4-year old AGMs with the same. We don't camp long enough in one place to justify lithium. AGM and our additons for power seems to be fine for our camping style.

I went with the single-panel Z-Amp because it is easly connected directly to the batteries with its built-in controller works directly with the factory system which I think was an HP controller back when it was built. Nothing new added to make it work. 

Arizonayeti

Even though I'm in AZ, I frequently camp under a canopy of trees or have the rooftop solar oriented the wrong way so I get very little power from that.  Thus, I added a Renogy 100w suitcase with 20ft of cable. It's overbuilt and I've even seen it produce >100w at times. I'm constantly checking the power production via the Victron app -it's kinda addicting. 

@pthomas745 is spot on on power usage with the 2-way fridge, lights, fans and parasitic losses. I was getting about 48hrs out of my 225ah 2 6v in hotter weather (not factoring in the rooftop solar). I could stretch that to maybe 60hrs if the fridge wasn't running as much and we were being careful with power use. 

Also, the Renogy 100w suitcase fits perfectly in the outside cargo area in my 2019 400. I just slide it on top of above a bunch of other stuff I store in there.  It's a tight enough fit you know it's not sliding and bouncing around and it comes with a sturdy protective case as well.  I believe you should have the same cargo area with the wider door in your 2018. 

Cheers!

Denny16

@NorthIsUp, I believe nüCamp primarily used the Victron MPPT 75/15 Blue in the TaB400 for the factory solar install.  We have a late 2018 TaB400 (Jan 2018 build) and it has the Victron solar controller.  You can get the Victron phone app and check to see if it pucks up a Victron controller.  If the dealer put your solar in, the. It could be an HP or nüCamp was using different controllers in 2019?

We had to replace the factory single AGM, the original OEM battery is not available any more, and the closest we could find was an Interstate 200 Amp AGM, that fits in the OEM battery location.
 Cheers 

pthomas745

There were different controllers worked into the first installed solar setups.  This thread, for a 2019 400, shows it as an HP 2440 B, which apparently has access to a bluetooth app that can be downloaded from the various app stores.  Seems it can use the "Renogy BT" app.  Searching for HP 2440 B on the Google brings back many different solar and  trailer companies used it.
https://tab-rv.vanillacommunity.com/discussion/7514/renogy-bt-app-for-sr-hp-2440b
Thread with a picture.
https://tab-rv.vanillacommunity.com/discussion/8373/help-using-solar-controller
So, non Victron factory solar installs are out there, a few, at least.

Denny16

Thanks Thomas, very interesting.  I remember the discussions of the HP controller on some TaB320s with Renogy panels.  Didn’t realize they used some on a TaB400.
Cheere

Aubrey

Unfortunately no factory solar on ours, so no victron controller. No battery monitor at all yet, just my multi meter and the wall mount 4 light tanks and battery panel.

That is why i am looking at 200w suitcase.
The PWM controller integrated in the Renogy i have read may be inefficient compared to the MPPT, but we are not using a ton of power or staying too long off grid (at least that is the plan).. 

I have been reading trying to understand if a better solar controller would act as a battery monitoring system as well, since you always hook the controller to the battery first anyway. Would it kill 2 birds 1 stone to have the controller on-board in that capacity (wired to battery in cargo area) and hook panels up as needed?

I may be coming at this from the wrong (cheapskate) angle. I sure appreciate all the info the forum is providing, thanks all.
 

Denny16

No, the solar controller only shows on the app, the current battery voltage (including the current going to the battery from the solar panel, so not a true battery (rested) voltage.  It also shows the watts/volts coming from the solar panel to the battery.  For your application and planned camping, going with the Renogy solar suitcase and connecting to the existing SAE plug you have on the trailer would be your easier solution.  

Either way, to accurately access your battery use snd voltage you need a separate battery monitor like the Victron Smart Shunt, which you can connect on the battery under the center bunk locker, and mount the shunt close to the battery.
cheers 

pthomas745

If you are handy with a multimeter, that is great.  With the battery switch off, and no power coming into the trailer, a fairly accurate voltage reading can be obtained.  You could even use the SAE port (that Zamp labeled thing) with your multimeter to take a voltage reading.  If you are comfortable with that, great.  Takes just a bit of practice ( and a "state of charge" chart.
The Victron solar controllers have a bluetooth app that will provide various "state of charge" voltage, solar input, etc.   Which is the difference in price on the Victron controllers. 
The "shunt" that Denny mentioned is a more advanced device that not only provides voltage data, but tells you how many "amps" you have drawn from your battery. Another bluetooth type device. 
So, bang for the buck: suitcase with its own controller, SmartShunt (only 130 bucks on Amazon today) and you get battery monitoring all built in.  

Aubrey

Sounds about right. I was thrown off by so many devices available, some sold without power-communication cords, etc...
Wife is getting a bit miffed that I won't just pull the trigger on some stuff. She doesn't hem and haw like me! I'm tight-fisted!
    Gonna look at those products today. Hopefully our travels will begin soon and I can learn all about it.

Aubrey

Based on some of the helpful comments here I am under the impression that the renogy 20' extension cable will not help me if the PWM controller is attached to the suitcase, sounds like if you have factory solar it is handy, but we have none. 
     I think this is the last issue I need to understand before going for it.
        You folks sure are patient with a novice like me. Ha!

pthomas745

What do you mean by "20 foot extension" will not help me?  

Aubrey

That the controller being fixed to the suitcase instead of near the battery negates the use of the extension cables. Perhaps the "marine cable" i have read about is the D.I.Y. solution? I know you want to avoid voltage drop but I'm only thinking 20'. 
   Maybe the 10' cord on the suitcase is enough. 
Boy am I overthinking this.

pthomas745

Ahh,..the line loss rabbit hole.  Usually, the "losses" for "short" cables used just to move the panels around are in the single digit percents.  I gave up worrying about it.  We aren't rigging up 50 panels and a dozen batteries.  I use these 10 awg cables from Windy Nation.  I have 20 and 30 foot lengths.  
https://www.amazon.com/gp/product/B01D7VBKQG/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1