Adding Solar Panels

[Danny boy]

I have a 2019 Thor Four Winds. I would like to add a minimum number of solar panels to the roof to charge the coach battery when dry camping. I have found solar panels that individually put out 100 watts. My MH already has the "Solar Charge Controller" wired in from the factory. My question is, how many 100 watt panels would be needed to charge one 12V coach battery on a sunny day over a period of 5 - 8 hours?

Thanks,
Dan

[HMCSW]

Do you have a residential refrigerator?

[Scubawise]

My tech recommended 1 180 watt panel..he removed the cheap 100 watt 10amp controller..if money issue try 100 watt 1st and test. Can always add

[Danny boy]

Originally Posted by HMCSW

Do you have a residential refrigerator?

I have an absorption-cooling fridge. It uses LP to power unless connected to shore power.

[Chateau_Nomad]

Originally Posted by Danny boy

I have an absorption-cooling fridge. It uses LP to power unless connected to shore power.

I figured you did. I have a similar 2020 class C. It came with the solar prep package... a GoPower 10amp controller and connection point on the roof.

I'm cheap, so I started cheap (except for the controller). First, I upgraded to a 40amp MPPT controller. Then I replaced the single 12volt marine battery with two GC2 (Sam's Club) 6volt golf cart batteries. Finally I researched solar panels... I found 100 watt panels for less than $90 each. I installed two on the roof.

I suggest getting as high wattage panels as your budget allows... 150 watts have come WAY down. You can easily add more as $$$ allows. And you can always upgrade your batteries... but you'll find batteries aren't cheap... just get what you really need.

We just returned from a weekender... batteries stay at 13.6 volts. Here at home, I simply check the water once a month... takes all of 5 minutes. Batteries are ALWAYS charged now... just one less thing to worry about.

[waynetaylor55]

Originally Posted by Danny boy

I have a 2019 Thor Four Winds. I would like to add a minimum number of solar panels to the roof to charge the coach battery when dry camping. I have found solar panels that individually put out 100 watts. My MH already has the "Solar Charge Controller" wired in from the factory. My question is, how many 100 watt panels would be needed to charge one 12V coach battery on a sunny day over a period of 5 - 8 hours?

Thanks,
Dan

The controller that comes "prewired" will only handle 10 amps. My FW had that and I had the dealership add a 190 watt panel that maxes out the controller.

I find, so far, that the one panel keeps my one battery charged enough (We haven't done a lot of dry camping, though).

I plan on adding a second battery and see how it goes.

Next option is to upgrade the controller to 30 amps and put up two more 190 watt panels.

[16ACE27]

Originally Posted by Danny boy

I have a 2019 Thor Four Winds. I would like to add a minimum number of solar panels to the roof to charge the coach battery when dry camping. I have found solar panels that individually put out 100 watts. My MH already has the "Solar Charge Controller" wired in from the factory. My question is, how many 100 watt panels would be needed to charge one 12V coach battery on a sunny day over a period of 5 - 8 hours?

Thanks,
Dan

Too many unknowns for a real answer:

What size, quantity, and type are your batteries? It will take longer to charge 100 AH batteries than 51 AH batteries.

How much current is used during the day? If you use all that's being provided by solar then your batteries will not charge.

What is the State Of Charge (SOC) of your batteries in the morning? It takes less time to charge batteries at 75% SOC than batteries at 50% SOC.

What time of year is it? There are more daylight hours at better angles in the summer than in the winter.

Realize that a 100 watt solar panel is usually rated at 5 to 6 amps at best.

So plug the unknowns into a simple math equation and get your answer.

[Danny boy]

Thanks for all of the responses!

Dan

[Pete'sMH]

I have a single 80W panel and it easily keeps my 2 house batteries and the chassis topped up while in storage. My controller failed a while back and I discovered it by noticing that the voltage was down to 12.2. Replaced the controller and had 5.8A output like normal. Batteries were all recharged when I checked a week or so later. I bought two panels thinking I’d need both but I’ve yet to install the second and have no plans to do so.

[Chateau_Nomad]

I think there's two things to consider:

Are you simply wanting a convenient way to keep batteries topped off while in storage, or are you planning to use solar as a primary power/charging source while traveling?

The first is pretty simple... a single 100 watt panel with good sun exposure will keep most any battery bank at full charge.

The second is more complicated. You find the amp hours of battery storage needed based on your anticipated power usage. Then add solar panels with enough energy output to recharge the batteries on a daily basis. Your budget most likely dictate how far you go down the "solar investment path".

[Danny boy]

Originally Posted by Chateau_Nomad

I think there's two things to consider:

Are you simply wanting a convenient way to keep batteries topped off while in storage, or are you planning to use solar as a primary power/charging source while traveling?

The first is pretty simple... a single 100 watt panel with good sun exposure will keep most any battery bank at full charge.

The second is more complicated. You find the amp hours of battery storage needed based on your anticipated power usage. Then add solar panels with enough energy output to recharge the batteries on a daily basis. Your budget most likely dictate how far you go down the "solar investment path".

I primarily want to be able to charge my batteries when dry camping. I have a generator, but prefer not to use unless necessary. Also, some campgrounds restrict generator usage and the solar option would help alleviate that problem.

Dan

[waynetaylor55]

Originally Posted by Danny boy

I primarily want to be able to charge my batteries when dry camping. I have a generator, but prefer not to use unless necessary. Also, some campgrounds restrict generator usage and the solar option would help alleviate that problem.

Dan

I plan on installing an inverter so that I can run my refrigerator on AC and not use up my propane (especially while on the road), run the tv without running the generator, make coffee without running the generator (no generators until 10am?), and use my microwave without running the generator. This will entail a second battery, 2500 watt inverter and running the output of the inverter (with ATS) to a sub panel that will have breakers for the microwave, outlets, and GFCI outlets rerouted from MH panel.

[Scubawise]

Originally Posted by Danny boy

I primarily want to be able to charge my batteries when dry camping. I have a generator, but prefer not to use unless necessary. Also, some campgrounds restrict generator usage and the solar option would help alleviate that problem.

Dan

I have a 180 watt solar and 3000w inverter.
When sunny & cool we have gone 3 days without noisy generator. That includes heating food in 1500w microwave and we watched TV.

Good luck

[Scubawise]

Originally Posted by waynetaylor55

I plan on installing an inverter so that I can run my refrigerator on AC and not use up my propane (especially while on the road), run the tv without running the generator, make coffee without running the generator (no generators until 10am?), and use my microwave without running the generator. This will entail a second battery, 2500 watt inverter and running the output of the inverter (with ATS) to a sub panel that will have breakers for the microwave, outlets, and GFCI outlets rerouted from MH panel.

Our 30 rv tech said no need for our inverter to use 12v absorption refrigerator. The 12v and very little propane used. In the montana mountains we have been off grid running the heat all night. TV, charge phones up to 3 days with daily sun. My guess we could do 4 or 5 days in emergency with sun and not needing to dump
I have a 180 watt solar and 3000w inverter.
When sunny & cool we have gone 3 days without noisy generator. That includes heating food in 1500w microwave and we watched TV.

[happy]

Scubawise
When the panels were added to your Vegas, what were they attached to?
Do the bolts or screws have to be in specific places in order to hold it securely
Not places on the panel, but places on the Vegas roof.

Yes, this is a basic newbie question.. I need RV Fix it for dummies!

[taylorbob1]

use the SEARCH function.
there's many many discussions on this topic regarding Vegas/Axis.

The roof is mostly 3/4" plywood, although there are some areas with sheet metal.

I used the "drill-less" solar mounts with rigid panels.
https://www.amazon.com/Renogy-RNG-MT.../dp/B01LWASUU1

Many on this Forum have gone with Flexible panels.
- Flex panels are more expensive, have a shorter warranty and life span, more heat is generated on underside of panel due to lack of airspace, thus reduces efficiency
- But very light weight & an EZ install with Eternabond tape around the edges

Personally...I have three 100 watt panels on drill-less mounts and a 30 amp controller + 2 standard Flooded Lead Acid batteries.

My system works superb, allowing full charging of batteries.
I power a 1200/2000 watt integrated inverter with auto-transfer switch 18hrs a day while boon-docking.
I can then use my Winegard Trav'ler and Hopper3 for nearly unlimited TV viewing if desired.

Since I can house just two batteries under the steps, I've chosen a small inverter.
Therefore, I must power my microwave and AC with my generator.

[Chateau_Nomad]

Originally Posted by happy

Scubawise
When the panels were added to your Vegas, what were they attached to?
Do the bolts or screws have to be in specific places in order to hold it securely
Not places on the panel, but places on the Vegas roof.

Yes, this is a basic newbie question.. I need RV Fix it for dummies!

I used aluminum "L" brackets designed specifically for the Rich Solar brand of panels I installed. They use a type of self-tapping bolt. When installing, I applied Dicor sealant to the bottom of the bracket where it contacts the rubber roof, drove the bolts through the bracket holes and firmly into the roof - then liberally coated the top with a layer of Dicor sealant.

CORRECTION: I FIRST applied a piece of butyl tape to the roof, slightly larger than the mounting foot, where the foot makes contact. THEN applied the Dicor to the bottom of the bracket... Looking closely you can see the butyl tape. Overkill? Probably... but that's the way I roll.

The pic is from an "inspection" I regularly do during storage in "Ohio winters" (notice the ice). The Dicor self-leveling sealant has held up excellent for about two years. When leaving a campsite, I do a quick visual check of the roof - including the panels. They are holding as tightly as day one.

[happy]

Actually I did use the search function but did not find what I was looking for. Being new and enthusiastic I use the search function nearly every day. Many times I have been successful in my search and have gained much knowledge from the website

Today, my search terms inputed to this question did not allow me find the information I wanted to know.

Thank you for the information about the drilless mounts and the roofing.
Also, apprecite C. Nomads info. That regular inspection is a good idea.

[Scubawise]

Originally Posted by happy

Scubawise
When the panels were added to your Vegas, what were they attached to?
Do the bolts or screws have to be in specific places in order to hold it securely
Not places on the panel, but places on the Vegas roof.

Yes, this is a basic newbie question.. I need RV Fix it for dummies!

I looked at the thor roof schematics.
You can get from owner site.
Shows exact places there are extra plywood plates to install items on the roof

[happy]

Thank you!

learning new resources everyday!!!!