solar

[SteveH]

After you choose what panel to go with I would get a battery bank monitor. That way you know exactly how many amp hours are being consumed and put back in, instead of guessing. There are many of them on the market. I have something similar to this. But you can also find less exspensive ones.

[Garyhjr]

Lots of Variables as you see to answer your question! Let me put it this way! 100watt solar panel is pretty much the equal to a 7.5amp battery charger! (I also am partial owner in a cabin in Canada, and am in charge of the solar power side! HAHA we have a 105 watt solar system and it came out to 7.5amps) So how much you use it and deplete the battery charge you will have it charge what it can! Running the 100 watts and see! how it works! all our lights are LED there and we run the radio pretty much all day and the lights at night and Never have issues! But each is different. But on our RV never run were we need the solar enough for it! Battery usually Last us 2 days in the camper with no issues! But then the TV charges the battery when you are moving! and when we are at home charged. I hope you got a little information from me to help.

[Bill Johnson]

Originally Posted by lefoster

I have two 12V deep cycle batteries. would a 100W solar panel recharge those in a day, or do I need 200W? I just want to get the briefcase, easy to carry, hook onto batteries as needed kind.

I know there are many factors, sunlight, use, etc., but in general would 100W or 200W handle it? or something totally different?

NO For a 100 AH battery:

Amps = Amp-hours / 20

Amps = 100/20

Amps = 5

So the battery will deliver 5 amps (at usable current, defined as 10.5 volts or higher) for 20 hours. You can draw more amps for less time, but the capacity decreases as the discharge rate increases. A 100 AH battery will only give you about 40 minutes at 100 amps of usage.

You can use amp-hours to figure out how fast your battery will charge as well. For a 100 watt solar panel, we already know that it produces 8.33 amps. In this case, 1 amp of current flowing for 1 hour charges the battery by 1 amp-hour. So 8.33 amps of current create 8.33 amp-hours of charge per hour.Fortunately, experts have come up with a rule of thumb. On average, a 100 watt solar panel will generate 30 amp-hours per day.

[Dgibbster]

I would highly recommend getting the 200w system.

[Thomson]

Here's a little pair of tools I use to determine what the actual draw is on the RV. First, I made a cheater cord from a piece of Romex known as 12/2 with ground. I cut the sheating near the center so I could put a clamp-on ammeter around the conductors. To know the current for example when the coffee pot is making coffee versus while it is keeping it warm. So you plug the cheater cord into an outlet and measure the currents and write them down. Now you can determine all of the current draws from each 110 volt appliance, tool, TV, etc. BTW the black wire is the hot wire. Also, suggest you insulate the ground bare wire.

Now the neat thing about this clamp-on ammeter is that it also measures direct current (battery). So you can shut off the power to the RV and get the draw on the batteries. Then start turning stuff on to see those effects, like the fridge, inverter for the TV, etc.

The name of the meter is Voltcraft Current Clamp Meter VC330; CAT II 600 V, CAT III 300 V, 2000 Counts, Compact and Robust, AC/DC Current Reading, Multimeter Functions, True RMS Readings, Resistance Reading.

Lastly, it's a noncontact voltmeter so you can use it to check a pedestal at a campground.

No I am retired, never worked for the company, etc. I just want to help.

[GHen]

I’m not aware of any 100 watt solar panel that will generate more than 5.6 amp hours.

I see quotes above at 7.5 and 8.3. You either of you have a specific product that generates that much?

[paulms]

Thanks for the info on calculating for solar panel.
How handy do you need to be to add the panels. While waiting until the campgrounds open I thought I would try to replace my batteries and add solar panels.
Everyone be safe.
Thanks.

[GHen]

My goal was to not need the generator for a 7 day boon-dock.

I installed one 100w panel and found it was particularly good at maintaining battery voltage as long as I didn’t use too much power. The solar charges four 6 volt batteries.
Then I added a second 100w panel and it was able to keep up with plenty of radio and a little bit of furnace, maybe 3 hours of satellite dish and tv.
The third 100w panel is giving me enough power that on most days I don’t need the generator. Unlimited satellite and tv and furnace.
Over time I’ll probably add a 4th panel to fully charge on cloudy days.

I may not get as much solar power as some, I live the the NW, lots of clouds and trees blocking good sun. Of course with good batteries I have no problem on day one or two with one panel. With three panels they get fully charged most everyday.

I can tilt my panels but would like enough power by letting them stay flat on the roof.

[X213_2015]

Originally Posted by GHen

My goal was to not need the generator for a 7 day boon-dock.

I installed one 100w panel and found it was particularly good at maintaining battery voltage as long as I didn’t use too much power. The solar charges four 6 volt batteries.
Then I added a second 100w panel and it was able to keep up with plenty of radio and a little bit of furnace, maybe 3 hours of satellite dish and tv.
The third 100w panel is giving me enough power that on most days I don’t need the generator. Unlimited satellite and tv and furnace.
Over time I’ll probably add a 4th panel to fully charge on cloudy days.

I may not get as much solar power as some, I live the the NW, lots of clouds and trees blocking good sun. Of course with good batteries I have no problem on day one or two with one panel. With three panels they get fully charged most everyday.

I can tilt my panels but would like enough power by letting them stay flat on the roof.

FWIW: I did a writeup of the install I did on my X213 here:

Jayco X213 Solar Installation – Restricted Ayerspace

I have boondocked for 7-day stretches all over the country. Part of the answer to the question "will it be enough" is highly dependent on weather and load. The fridge takes barely any battery to operate (running on propane)..the heater however is a different story and my one (old) battery overnight on a recent trip to Vermont in the fall was not up to the task (we also had rain/no sun to top-off the battery during the day). I was fine down in Yakima for a week and in Olympic for a week - but I didn't need to run the heat and it was manly used to charge phones and lighting.

I had good luck in Shenandoah Valley for a week too...with mixed weather - but again temps were nice enough to not need heat.

We also had only one day of overcast/mist in Olympic which is unusual - the rest was sun. I'm pretty happy with the system I installed and it met my needs - but I think I would go to dual batteries and maybe add a 3rd panel. So where you plan on boondocking will make a difference when answering the question. Northern Canada - chances are you'll need more pannels to top off your battery.

[BCx213]

I have a Go Power 120 watt Solar suitcase, the controller in full sun shows 6.7 amps. If you want full charging it has to be facing the sun. Cloudy/rainy days as well as shade effect the output...It drops to about 1 amp or less. I back up with my generator as needed

[GHen]

X213, nice write up on your solar install!

[turbo130]

I really like your write up on your solar install, I use a predator 3500 watt generator. In the 5 1/2 years that we have owned our trailer we have only used it 3 times. I can't justify installing a solar unit, how ever as we start using our trailer more solar may be the way to go.

[Bill Johnson]

I'm surprised more campers don't use the predator generator instead of Honda and others. They have great reviews, low prices, quiet and put out more amps. Most of the lawn equipment is going to Chinese engines and they hold up well. It's to bad we can't make anything here in the US

[turbo130]

Sad but true, just started and ran my predator for 30 minutes started and ran like a spinning top.

[Colorado]

I bought this last Fall when it was $360, it has the Bluetooth battery monitoring included. The set up works great.



Renogy 200 Watt 12 Volt Off Grid Premium Monocrystalline Solar Panel with 20A MPPT Rover Controller/Mounting Z Brackets Adaptor Kit/Tray Cables Set /MC4 Fuse, 200W-20A https://www.amazon.com/dp/B07CTHCZJ3..._7AKPEbKAJQGMX

[daveobieone]

We have 600 watts of solar on the roof...But we are power hungry animals!!!

By 10am on a sunny day we are fully recharged. By noon if it's cloudy.

Seriously, we use power when we are off-grid like we are at home...except we don't run the A/C.

The two 300 watt panels feed two 6 volt golf cart batteries in series, via a 40 amp MPPT charge contoller. 100 watts on the roof would never be enough for us. We burn mega-watts. :-)

dave o.

[Akraft]

Use what ever your proposed battery is rated at to estimate your solar panel size. To use me as an example, I have 215 amp-hr batteries. You can actually use half. That leaves me 107.5 amp-hrs.

If wanted to get the most out of my batteries for dry camping I need to calculate how much it would take per day to replace that.

Sunny Day: On a good day you get your full current. At 30 amp-hrs per 100 watts (per day) on a good sun light day it would take 358 watts to re-charge may battery if I drained it to 50%.

Hazy Day: On a hazy day figuring only 60% output current that would reduce to 18 amp-hrs per 100 watts. So if you want to insure you can replace 107.5 amps hrs on a hazy day that comes out to 560 watts.

If you just have the standard 75 amp-hr battery it lowers the size panel to about 1/3. Sunny Day 107 watts and on a Hazy day 186 watts to replace a 50% discharge.

[jeffmcpa]

Originally Posted by Akraft

Use what ever your proposed battery is rated at to estimate your solar panel size. To use me as an example, I have 215 amp-hr batteries. You can actually use half. That leaves me 107.5 amp-hrs.

If wanted to get the most out of my batteries for dry camping I need to calculate how much it would take per day to replace that.

Sunny Day: On a good day you get your full current. At 30 amp-hrs per 100 watts (per day) on a good sun light day it would take 358 watts to re-charge may battery if I drained it to 50%.

Hazy Day: On a hazy day figuring only 60% output current that would reduce to 18 amp-hrs per 100 watts. So if you want to insure you can replace 107.5 amps hrs on a hazy day that comes out to 560 watts.

If you just have the standard 75 amp-hr battery it lowers the size panel to about 1/3. Sunny Day 107 watts and on a Hazy day 186 watts to replace a 50% discharge.

If I understand this correct on the sunny day - It would take about 3.5 hours @ 30-amp hours to get the charge back (3.5x30 = 105) ?
On the cloudy day - around 6 hours at 18 amp hours (6x18 = 108) ?

Do I have that correct, or am I missing something?

[GHen]

Yes, but to get 30amps per hour you would need 6 100watt solar panels. In the south with tilted panels you might get away with 5 panels.

[SammyG]

I would like to add Solar panels to my 2019 Entyegra Odyssey 26D with solar prep package? I would like to be able to run a TV, LED lights, charge batteries, phones, maybe DISH satellite. My coach does not have an inverter. Can someone chime in on what I need to get myself going solar.