Solar Experts-Does this sound right to you?

[MMH]

I'm in the process of buying a 2020 Intent 28Y. Since it has a residential refrigerator, I was planning to put in two lithium 105 AH batteries and 600 watts of solar. It is prepped for three connections. Then I got to looking at the spec sheet and it says it is rated for 450 watts of solar. When I asked the salesman about whether the 600 is too much, this was his reply:
"Each panel carries a certain amount of watts. Our panels handle 200 watts but carry 9.2 amps per panel. This is most important as the controller is a 30amp controller.
So your system will be able to handle the 600Watts as the total amps are 27.6 amps. If the amps exceeded your system, we would have to reduce the amount of panels."

Does this sound right? Any input on this is much appreciated.

I boondock for a week at a time in my current TT. I am worried about the residential fridge so I was trying to assure that I'd be solid without running the generator. I go to the mountains for peace.

[creativepart]

Nope. Not correct. But you’re close. Between 400 and 500 watt should get you close to 30-amps.

And forget your plan to go a week without running the generator. Even with the Lithium batteries and solar you will have trouble going two days. I’d guess you will have to run the generator some every day.

Never ever trust what the salesman says.

[DavidM]

There are two issues to be concerned with if adding 600 watts of panels:

Connections and size of wire from the junction box to the controller. I suspect that the junction box on the roof combines the three connections into one parallel one to feed it to the controller. So first, install 24V nominal panels to keep the voltage drop down. You can buy 12V nominal 200 watt panels these days on Amazon and these will double the current and double the voltage drop which will almost certainly result in too much drop.

Secondly the controller will probably be too small. Controllers are usually rated as their amperage output to the batteries. This could be as high as 600/12 = 50 amps, too much for the controller.

So I would replace the controller with a Victron MPPT 100/50 one. Also the existing controller is probably a PWM type. The MPPT type will provide 10-15% more amperage.

David

[creativepart]

As David says. Wiring is an issue. Winnebago uses 10 gauge wire from the roof to the Zamp 30-amp PWM solar controller. And also from the controller to the batteries.

(It’s very likely they still use Zamp controllers, but it is possible the factory has changed suppliers.)

At 12v you’re good to about 30-amps. And the fusing in the Zamp 3-port input on the roof is also 30-amp.

Since you asked us (non experts) I’d also be concerned with what batteries they are installing and what they are charging you for all this. We have seen others posting after having a dealer do this work with unknown equipment at a very high price.

About Boondocking with the residential fridge...

You’ll be happy with the fridge but you have to adjust your expectations some. You will be able to dry camp overnight without problems on 210 amp hours of Lithium batteries, but that would likely take you down to about 60% state of charge. Which is no problem. But during the subsequent day you’ll be using another 40% of your batteries while adding back a varying amount of amps from your solar panels depending on the sun. Probably not enough to power your day and also charge you back up to 100%.

That again is no problem except that you’ll have another 12-hrs of darkness and use another 30-40% of your 210 amp hours.

You can use 80% of your battery’s amp hours without problem but that’s not enough for a week without running your generator.

No worries though, most find that one or two short recharging generator runs a day will keep you going for that week. Time the gen usage with microwave usage, meal prep for breakfast and dinner, and you should be fine.

I assume you’ll have a 2000w inverter. That’s great and can be used for short usage of the microwave, coffee maker, hair dryer, etc. but you’ll be surprised how much power those things will use.

One or two final things.

You will definitely need some other battery monitor than the RV’s voltage meter with your Lithium batteries. You should make sure to get a shunt based battery monitor as part of your install.

And you will need to investigate the usage of your RV’s alternator to charge your Lithium batteries while driving. That’s a bigger subject that you will at the least need to be aware of.

[MMH]

Thanks for the replies! This stuff can make your head spin! I'm a long time travel trailer RV'er and a very low user of power, but the fridge thing and now the addition of running a motorhome is just a little more learning. I was reluctant to have the dealer install the solar, but since we are buying new, I'm trying to balance cost with headaches later when they try to say that issues were from some other installer and then question the warranty. The stock inverter is 1,000 I think.

This being said, I was installing 6V, then got down the rabbit trail of lithium and forgot about the alternator thread, which I saw while researching. I'll look that up. I do not understand why dealers don't understand that many of us would happily pay for a quality install of the right product and then would subsequently send business their way vs. selling subpar and leaving RV owners frustrated! A really great thing would be if Winnebago just broke it down into three solar packages based on the type of user you are and you just pick a, b, or c. There could be great economy of scale and much less pulling of hair!!

Solar is such an awesome tool. I've had it on both travel trailers and we have it running 100% of our house power.

[creativepart]

Dealers!

The dealer sees you as a short term profit center only. You will quickly learn that the dealer and his service department are not your friends. For the vast majority of motorhome owners the dealer is to be avoided. There are a few exceptions to this, but less than a handful around the USA.

It’s very likely that you know more about your new RV than the salesman, regardless of how knowledgeable he or she may pretend to be.

[creativepart]

My 2017 Winnebago gas Class A came with the residential fridge but that package included 4-AGM batteries instead of two and a 2000w inverter instead of the 1000w unit. As a separate option, it also came with the solar install from the factory. One 100w panel, 3-port Zamp roof portal and 30-amp Zamp PWM controller.

So, I have 400 amp hours af AGMs. But I work hard to not use more than 50% of that to extend my battery life. This has been very acceptable.

I added two more 100w panels, and changed out the Zamp controller with a Victron SmartSolar MPPT 30-amp controller for more efficiency and Bluetooth reporting. I also added a Victron battery monitor.

When dry camping I run the generator about an hour or less in the morning and about 2-hrs in the evening. With this I’m good for the four days until my gray tank is full.

FWIW, when my batteries start fading I too will likely replace with lithium batteries. But I’d want at least three of them.

[Winterbagoal]

Originally Posted by MMH

I'm in the process of buying a 2020 Intent 28Y. Since it has a residential refrigerator, I was planning to put in two lithium 105 AH batteries and 600 watts of solar. It is prepped for three connections. Then I got to looking at the spec sheet and it says it is rated for 450 watts of solar. When I asked the salesman about whether the 600 is too much, this was his reply:
"Each panel carries a certain amount of watts. Our panels handle 200 watts but carry 9.2 amps per panel. This is most important as the controller is a 30amp controller.
So your system will be able to handle the 600Watts as the total amps are 27.6 amps. If the amps exceeded your system, we would have to reduce the amount of panels."

Does this sound right? Any input on this is much appreciated.

I boondock for a week at a time in my current TT. I am worried about the residential fridge so I was trying to assure that I'd be solid without running the generator. I go to the mountains for peace.

Why not go with your original plan, 2X 105Ah lithium iron phosphate batteries, but trim back the solar to 450W as the manual suggests? If your panels are as good as the SunPower/Zamp panels that came with my Navion, you should get around 22-25 amps in good sun. I would think that will be plenty during the daytime to run everything you need while charging the batteries, and should give you lots of battery for overnight. Rinse, repeat. Before you decide it would be nice to figure out how much power you'll use overnight while the solar pamels are asleep. Would give you a better idea of how many panels you'll need.

I'm no expert, and I will admit that I do try not to over think this stuff.

I swapped in 2 X 105Ah Relion lithium batteries last year, and I only have 300w up top (I added a 3rd 100W panel to match the 2 that came standard on my Navion), running through a Zamp ZS-30A PWM controller (factory install) that came with the rig.
I also have the power hungry Norcold DC0061 fridge, that pulls as much as 6.5A when running.
So far I've not run out of battery power with my set up, but it's only been tested once earlier this year on a 4,000 mile trip, and not for more than 2 days off grid with no other charging source. Besides the fridge, we don't use a lot of power except for lights, some TV if there is any OTA available, and the roof vent fan at night. And whatever other usual vampire draws on the coach batteries.
I'm also running the stock MB Sprinter engine/alternator combo, without any additional hardware. So far, so good, on that one over 4,000 miles. I figure unless the batteries are drawn down to almost zero, the alternator isn't going to knock itself out sending charging current to a battery that's already near full. This is just my opinion, of course. If something bad happenes I'll deal with it then.
I agree, solar is impressive on this scale.

[creativepart]

Thinking about the pricing - If you DIY the two LiPo batteries and added two more 150-160w solar panels, again DIY, your total cost would be less than $2500. And, take you less than one days work.

What's the dealer want to charge you? I'm guessing the dealer is quoting ~$5000 or more for the job???

I certainly wouldn't worry that you DIYing a battery/solar panel install is going to materially effect your RVs warranty going forward. Of course, you have to do what's comfortable to you on this point.

[DavidM]

One thing that is often overlooked in the switch to lithium batteries is the converter. At least on small RVs it often has a 45 amps converter and is not optimized for Li batteries so the last 10-15% never gets charged up.

You can replace the existing one with a Progressive Dynamics 9180AL converter and get 80 amps rather than 45 and the charging profile is optimized for Li batteries. This should cut your genset running time almost in half and add 10-15% to the available amp hours from the Li batteries.

David

[creativepart]

Because the Intent is a less optioned motorhome and has a 1000w inverter I'm going to presume that it has a typical Converter/Charger rather than an Inverter/Charger. So, LiPo charging may be an issue. It's not an immediate issue and maybe something the OP would want to tackle down the road.

We have plenty of Intent owners here that can fill in the details on this and what model Converter it has standard from the factory. Some of the newer Converters are Lithium ready and some are 60 amp, too.

UPDATE: Looking at the parts list for this model/yr it should be a WFCO 55-amp model. I don't know if it's a 8855 or 8955. But both seem to be capable of charging at 55 amps and at 14.1vdc. Some of WFCO's models are described as "Lithium ready." I'm not positive about the model installed in the Intent.

[MMH]

Originally Posted by Winterbagoal

Why not go with your original plan, 2X 105Ah lithium iron phosphate batteries, but trim back the solar to 450W as the manual suggests? If your panels are as good as the SunPower/Zamp panels that came with my Navion, you should get around 22-25 amps in good sun. I would think that will be plenty during the daytime to run everything you need while charging the batteries, and should give you lots of battery for overnight. Rinse, repeat. Before you decide it would be nice to figure out how much power you'll use overnight while the solar pamels are asleep. Would give you a better idea of how many panels you'll need.

I'm no expert, and I will admit that I do try not to over think this stuff.

I swapped in 2 X 105Ah Relion lithium batteries last year, and I only have 300w up top (I added a 3rd 100W panel to match the 2 that came standard on my Navion), running through a Zamp ZS-30A PWM controller (factory install) that came with the rig.
I also have the power hungry Norcold DC0061 fridge, that pulls as much as 6.5A when running.
So far I've not run out of battery power with my set up, but it's only been tested once earlier this year on a 4,000 mile trip, and not for more than 2 days off grid with no other charging source. Besides the fridge, we don't use a lot of power except for lights, some TV if there is any OTA available, and the roof vent fan at night. And whatever other usual vampire draws on the coach batteries.
I'm also running the stock MB Sprinter engine/alternator combo, without any additional hardware. So far, so good, on that one over 4,000 miles. I figure unless the batteries are drawn down to almost zero, the alternator isn't going to knock itself out sending charging current to a battery that's already near full. This is just my opinion, of course. If something bad happenes I'll deal with it then.
I agree, solar is impressive on this scale.

Winterbagoal, perhaps the best advice is your quote: "I'm no expert, and I will admit that I do try not to over think this stuff." I tend to research and research. I am learning a bunch though from all the input from everyone. Thank you for your example you posted. Whatever I end up with I will post how it works for us so others will have a reference in the future.

[MMH]

Thank you for the additional details all! I think one challenge on these setups is each model year evolves and then it's hard to pin down what each person needs. I don't think I realized how critical the converter is or the opportunity to improve the efficiency.

I'm thinking once I am set up I can optimize once I see how it all works together as long as I have at least an adequate/safe system to start. Wish I was as handy as some of the folks on this forum are!

[MMH]

Originally Posted by creativepart

Thinking about the pricing - If you DIY the two LiPo batteries and added two more 150-160w solar panels, again DIY, your total cost would be less than $2500. And, take you less than one days work.

What's the dealer want to charge you? I'm guessing the dealer is quoting ~$5000 or more for the job???

I certainly wouldn't worry that you DIYing a battery/solar panel install is going to materially effect your RVs warranty going forward. Of course, you have to do what's comfortable to you on this point.

The 200 w panels are $599 and the 105 ah batts are $899. So they're actually not as far out as you might think from the dealer. I did negotiate the price some. Typical dealership, walking through talking options they tell you one price, then once you tell them what you want a few days later, they try to tack on literally another $200 each for the panels and $50 for batteries. Guess they thought I was unconscious the first go-round! It's so irritating. I plan to wait and see what the entire process is like and then post a detailed review of their overall customer service. I'm hoping they surprise me (in a good way) when I go do the walk through and pick it up. Dealers underestimate the power of social media I think. There are definitely good ones out there. We'll see about this one. They're in Boise. We have a travel trailer company in Pendleton that puts every dealer to shame. Just wish they sold motorhomes. Best RV company in the country!

[DavidM]

Another way to do a solar installation is to ask around marinas and boat yards to find a good marine electrician. Virtually all of the issues in a solar installation on a boat, apply to RVs. They will charge you a steep hourly rate, as much as $150/hr but will probably charge you for parts at list price (they keep any discount) or will install equipment that you supply.

David

[creativepart]

I'm sure when you tell your dealer that people on a forum told you that 600w was too much for that system they will tell you what they think of "social media."

After all, they are true RV experts and people on forums are navel-gazing dweebs.

Which might be true on some other forums, but I'm confident that's not the case here. Right dweebs?

[AJMike]

I have seen just shy of 20 amps being generated by the 300 watts of solar in our Fuse. That theoretically exceeds the maximum specified for the SunPower solar panels so I would be careful if I were you. Personally I would not exceed 450 watts of solar for a 30 amp solar controller.

Of course the current you get will depend upon several things including where and when you are camping. Here in Arizona the sun is very, very strong in the summer and the 300 watts often give us 15-17 amps, but less in the winter when the sun is lower in the sky. But I would not team up 600 watts of solar with a 30 amp solar controller.

As for how long you can dry camp or boondock - we find that our RV with its compressor refrigerator usually uses between 75 and 120 AH of power every 24 hours if we don't use high consumption appliances, so how long you can camp depends upon how much sunlight you get. Our 200AH of BB Lithium gives us between 2 and 3 days before we have to either run the generator or go somewhere else and charge the batteries by driving.

Lately we have been able to camp for less time because my wife has started to use her electric tea kettle and toaster as well as AC fans, all off of the inverter. That has reduced our boondocking time to 1-2 days before we need to take some sort of action, so you should examine what you plan on doing that will consume power before deciding how long you can stay in one place.

[DavidM]

AJMike:

Did you upgrade your converter to reduce generator running time with your Li batteries as suggested to the OP in my post #10?

Also from my boating experience I would start up the generator any time we had a high AC draw need, like your wife's toaster and tea kettle use. Start it, wait a minute or two for it to warm and then use it to power your heavy AC needs and then shut it off. Or once done let it run for a while to recharge the batteries.

It is much better to power heavy AC loads directly from the generator than to use your batteries to power an inverter to supply them and then have to recharge the battery later with the generator, particularly with a small converter.

I realize in some campgrounds you can't run the generator always when you need it.

David

[AJMike]

Originally Posted by DavidM

Did you upgrade your converter to reduce generator running time with your Li batteries as suggested to the OP in my post #10?

No. We added the Lithium batteries, the DC-DC charger and one extra solar panel to the roof, but nothing else. However we did add the Progressive Dynamics pendant which changes the charging profile to that for Lithium and that seems to have taken care of the issue. As far as I can tell our batteries fully charge when using the converter as long as we have the pendant set to the Lithium profile.

Originally Posted by DavidM

Also from my boating experience I would start up the generator any time we had a high AC draw need, like your wife's toaster and tea kettle use. Start it, wait a minute or two for it to warm and then use it to power your heavy AC needs and then shut it off. Or once done let it run for a while to recharge the batteries.

We don't use the generator for that purpose, primarily because DW hates the sound and smell of the generator and is much, much happier if we don't use it.

On those occasions when the interior of the RV gets hot, like during the late Spring, Summer and early Fall here in Arizona, I will turn on the generator and the AC for a bit while we walk through the campground so that we can cool off the inside before we go to sleep when that is permitted in the campground, and simultaneously charge the batteries, but that is pretty much it.

Originally Posted by DavidM

It is much better to power heavy AC loads directly from the generator than to use your batteries to power an inverter to supply them and then have to recharge the battery later with the generator, particularly with a small converter.

Why?

Originally Posted by DavidM

I realize in some campgrounds you can't run the generator always when you need it.

Yes, and as I mentioned earlier that is one of our main issues, and one of the reasons we got the Lithium batteries. Some places we go will not allow generators at all, and some have very restrictive hours, say 10 am to 2 pm only, and our Lithium batteries make it possible for us to camp there.

[creativepart]

Mike, using the generator for heavy loads instead of battery/inverter just keeps your batteries at a higher state of charge and usually with less overall generator run time.

If I remember you don't use your Microwave on inverter, but other heating appliances take a big toll on your batteries when used via inverter.

We have 400 aH of batteries and a 2000w inverter but 60 seconds of microwave will take about 8% of our State of Charge... just that quickly. Recharging 8% of the charge back can take 20 mins or more with the generator. However, I have AGM batteries and so the comparison for you with Lithium isn't the same.

Anytime we're using the microwave or the Keurig Coffee maker we start the gen. Even if it's on the side of the road when making lunch. We run the generator for 5 mins just to warm it up and cool it down, using the microwave for about 1 to 2 mins of that time. And as a result we don't lose ANY charge out of the batteries.

I do know that it's likely that running the generator in our 38' Class A is nowhere near as noisy or unpleasant as it is in a smaller Fuse Class C.