RV Solar System?

[slabm7]

Looking at camping off grid more and more and would like a reliable power supply without having to run a generator 2 hours a day. I would also like to hook an inverter up from the batteries to power the trailer AC. Just for basic phone charging or for the kids to watch a movie. Not looking to run any large amp users like microwave or A/C, but just basic use of lights and water pump for DC stuff. I’ve been looking at anywhere from 100w-300w systems. I have 2 decent batteries already that I would use. Any recommendations?

[sewerrat]

I have a 100 watt Noma panel on my roof, comes with controller and all, they go on sale at Canadian tire once in awhile, I think I paid little over $200 and I have never been with a dead battery. Works perfect.

[Xiph0id]

IMO, the key to a system is 3 part. Battery and panels + power draw.

1. Get a good battery. Normal lead acid are crap. I prefer a single 12 v gel or 2 6 volt batteries.

2. Size panel for what you use.

3. Switch all lights to LED. Huge difference.

Reading your post "decent batteries" will be a challenge.
They will not last nearly as long a proper battery setup.

[curtz]

I'm running four 6 volt batteries with a 200 watt solar panel, my biggest draw is the furnace on May long weekends. 36ft trailer, the furnace runs a lot at night, never run out of power. Always have the genny just in case.

[slabm7]

Originally Posted by Xiph0id

IMO, the key to a system is 3 part. Battery and panels + power draw.

1. Get a good battery. Normal lead acid are crap. I prefer a single 12 v gel or 2 6 volt batteries.

2. Size panel for what you use.

3. Switch all lights to LED. Huge difference.

Reading your post "decent batteries" will be a challenge.
They will not last nearly as long a proper battery setup.

They are 2 Costco Deep Cycle batteries that are 3 years old, I would love to go to 4 6v batteries but that’s getting a little pricey. I’m hoping to make the batteries I have now last a few more years.

[bushnell]

The Noma are on clearance at Cdn Tire. Picked up some last weekend

[Xiph0id]

Originally Posted by slabm7

They are 2 Costco Deep Cycle batteries that are 3 years old, I would love to go to 4 6v batteries but that’s getting a little pricey. I’m hoping to make the batteries I have now last a few more years.

I hear you. I've mulled over it too.
My next one will be a yellow top optima.

Problem with the lead acid, is they run out of juice after so many cycles.

Costco RV battery was great for season 1 and 2. Not as much 3-4

[javlin101]

I did the solar, 6v batteries, switch the converter for an inverter/charger on 2 RV's

Just remember, when camping most people try to find shade to keep the rv cool. This really hampers the solar ability to do it's job. On my trailer if parked in the back yard the solar did great, campinging at a nice site with trees not so much. My motor home I changed out the converter for an inverter/charger as I had an on board genset. Best system I had.

With solar it is highly unlikely your going to run air so you do not want to park out in the sun which is what the solar needs. Just saying.

[Geraldsh]

I use a portable solar unit with 30’ cord and alligator clips to battery. I can aim at the sun and still park in the shade. 100 watts charging 2 deep cycle 12 volt RV batteries.
Drwawback is I have to put it away when I leave the site because it’s too easy to steal.

[Ronbill]

When I added solar to my 33' travel trailer a few years ago I learned that watt for watt it is cheaper to go with the a 60 cell 24v residential (grid-tie) panel rather than the RV rated 36 cell 12v panel as anything made for RV's has a super inflated cost to it. I paid the same for a 250watt 24 volt grid-tie panel for the same price as a 150watt 12v RV-specific system.

With the 24v panel you will require an Maximum Power Point Tracking (MPPT) type charge controller to go from 24v panel to 12v RV battery system rather than the older and less efficient Pulse Width Modulation (PWM) charge controller that isn't compatible with both voltages. Because the MPPT controller can accept charge from a panel of higher voltage than the battery bank, the extra AMPS produced yield greater efficiency in charging the lower voltage RV battery bank. Just google MPPT vs PWM and decide what is best for you.

I went with the Blue Sky Energy Solar Boost SB3000i charge controller that is a 'Smart' controller that regulates proper battery amp charge based on incoming amps and battery/ambient temperatures to avoid over-charging.

For batteries I went with 2 6v 'golf cart' batteries, but if you really want to run small appliances I'd recommend at least 4 6v batteries.

As others have mentioned, change all lights to LED. There again, don't buy them from an RV dealer as you can get the exact - I mean EXACT - led bulbs off the online auction site or from overseas for a fraction of the price.

Also, pay attention to the guidelines for proper gauge of wire you should use based on the distance from the battery to the charge controller and to the panel. This is important for efficiency of the charging system.

Good luck.

[BUSHRVN]

I just did this on my trailer for two main reasons. One is so that I didn’t have to structure my day plans to be back at camp to maximize generator time in the allowable slot while in provincial or NP sites. The other is better control and conditioning of the batteries which makes them last longer, less boiling and desulfation cycle every 28 days automatically.
I’m running two Trojan T-105 plus 6volt batteries, three 160 watt flexible panels on the roof for a total of 480 watts and a GoPower PWM 30 amp controller. I ran #4 welding cable from the controller to the batteries for minimal current loss at 32’ long.
I had my first test of it on maylong weekend. I was in a full hookup site but I turned off the breaker feeding the converter so I could try it out. It’s a 34’ trailer with five of us, all led lights, two shower session per day etc. and running the built in fuel pump to fill up five atv’s each day as well. Fairly heavy power usage overall. The furnace was cycling all night as well. Each morning by 9:30 the batteries were back up to 100% which totally surprised me really. The panels were also shaded by trees at those early hours. On the day we left it was totally clouded over and raining. We had big power draws from the slideout, dual rear bed hoist and a very heavy tongue jack usage but at 10:30 when I was about to plug in the truck to the trailer it was at 100% already. It seems that maybe 320 watts worth of panels may have done the trick, but too many never hurts for sure.
With using the flexible ones, which cost more, you can tape them down with eternabond roof tape and not make any holes at all in the roof. I ran the wiring in through the fridge roof vent as well. Zero holes in the roof.
I chose the GoPower controller because I liked how they have lots of accessories that are well integrated. For example, if I want to add an inverter it can be controlled from the controller panel that I already have in the trailer via a phone line cable which I roughed in while installing the panel so I wouldn’t have to open it all up again later. Second is that this panel has Bluetooth and an app for the phone so you can see all your info on the phone from amp hours, current charge amps, current volts, percentage of charge and you can turn the inverter on and off from the app as well. The Bluetooth works from 100’ away, I can connect from inside my house to see what’s happening out there.
I thought about portable panels so that I could position them for optimum sun angles, but then I’d have to deal with them, store them and worry about theft etc. So I went with permanent roof mounted ones and went overboard with wattage to help compensate for shade losses and cloudy days. Time will tell.

[Rustynail21]

There are some pretty smart guys here that have nailed it. If you can afford it, don't cheap out. The MPPT controller will rock your world. I can switch from parallel to series depending on the camp spot and sun and really crank out the amps. Series for full sun on both panels and parallel for if I'm headed to the beach so I can catch the sun at two angles. Setting it up in series also will save on loss through the cables.

I'm a Renogy guy, did some research and heard some good things from a few buddies. Had one warranty issue on a bluetooth adapter (letting me check my stats from my phone) and they sent me an upgraded new one to ensure I would have no further issues. I used their Rover 20 amp MPPT which is affordable around $100-$150 and one suitcase 100 watt and one flexible 100 amp panel. Love them so much I've had to buy a portable controller (not MPPT) for friends that come camping so I don't need to hear their generator. I give them one of the 100 amp panels and even one 100 amp panel each keeps us both topped off enough for a long weekend as long as we have a few hours of sun.

For batteries, I started with 4 Costco 12 volt deep cycle batteries and intend to go to 4 - 6 volts when they go. That being said, the 4 12 volts are dated April 2009 and are still doing great. I never let them drop below 75% when camping and store them inside during the winters.

It's a lot of fun playing with solar, I've had a blast getting to where I am. I enjoyed researching and paying around with arrangements to make things work. Few other heads up, your inverter should be pure sine wave, not modified or stepped waves. My pellet smoker won't run on anything but pure sine wave, worst time to find out is 3 am when prepping a cook for 20 people. Eventually you'll upgrade your converter in your trailer as well, it becomes a never ending rabbit hole (and money pit). Add lots of fuses, they are your friend. Zamp connectors for the trailer make things easier and fit a standard 2 prong, which you can get in 10 gauge from princess auto.

Good luck and reach out if needed!

R

[BUSHRVN]

I should mention also, you can mix and match components. My solar panels are Renogy 160 watt flexibles because they were quite a bit cheaper than GoPower yet a very reputable brand. I chose GoPower for the controller because of its features, add on accessories and flush mount.
These’s some very good points here like the advantages of the MPPT controllers and residential solar panels which I never though of while researching my system and piecing it together.

[slabm7]

Thanks guys! This is the exact type of info I was looking for!

I've been really looking at the Renogy stuff, seems reasonably priced for the wattage you get. And the clarity on the different types of controllers is perfect. I didn't know much about them. I was looking at buy a 2000w inverter generator to compliment the solar system if needed but I'm getting the impression that if I do the solar system right I won't need it. The only thing a generator would be nice for would be to run the A/C if the trailer is hot before putting the kiddos to bed.

Time to start shopping!