Adding solar panel

[wademartin]

I have a 5th wheel camper with two Exide Stowaway Group 27 Marine/RV batteries wired parallel that powers my 12 volt panel and connected to a 300 watt inverter that powers my CPAP machine, my satellite receiver, flat screen TV, electric razor and cell phone charger when off shore power. To maintain my batteries I proposed to add a 100 Watt Polycrystalline Solar from Grape Solar on the camper roof with a Sunforce 10 Amp Digital Charge Controller. Any comments, suggestions or advise will be appreciated.
Thanks, Wade

[kjchipmunk]

I have 450W and an inverter with (4) 6V batteries in series parallel. I'm surprised at how quick the batteries draw down. You can read more about my stuff here http://www.jeromesrving.com/5thwheel/2015/2/9/solar-on-the-rv . Zamp Solar has a CPAP system that is stand alone, but it sounds like you could just power up more on what you have and be OK. http://www.zampsolar.com/product/cpap-power-system-zp-600ps-cpap/

[justme]

http://www.gonewiththewynns.com/flexible-solar-panels-rv

[laknox]

wademartin wrote:
Following suggestions from responses I have received, I have decided to go with a 200 watt kit with a 20 amp charge controller. I may have to add to my battery bank since my CPAP runs on 110 volts. Your responses were very helpful. Thanks to all of you.
Wade

Wade, seriously, if you're going to add more 12v batteries, re-think and think about changing to 6v. You can get 6v golf cart batteries at Costco or Sam's for about $80-90 each (last I looked), and cross-over cables are about $12-15 each. If you're going to go to 4 batteries, make 'em 6v and you'll have a =lot= more capacity, even if you take the other suggestions to heart. There was one post I read a couple years ago on here, from a =serious= boondocker, who has 6 2v batteries and a =lot= of solar, so was power-independent. Almost 1,000 lbs of batteries, though. 🙂

Lyle

[SkiSmuggs]

wademartin wrote:
Following suggestions from responses I have received, I have decided to go with a 200 watt kit with a 20 amp charge controller. I may have to add to my battery bank since my CPAP runs on 110 volts. Your responses were very helpful. Thanks to all of you.
Wade

Check to see if your CPAP will run on 12V (most do), then you can eliminate the inverter overhead. I have 2 different CPAPs and was able to find a 12v cable for each. Another idea to keep from depleting your house batteries is a 35AH sealed deep cycle battery to run your CPAP that you can charge independently. I haven't tried that, but it should be good for 2-3 nights with direct 12v.
Since most CPAPs run on 12v, the standard adapter converts 120v to 12v. When you use an inverter, you convert 12v to 120v, then back to 12v via the adapter to run the CPAP. Direct 12v makes so much more sense.

[wademartin]

Following suggestions from responses I have received, I have decided to go with a 200 watt kit with a 20 amp charge controller. I may have to add to my battery bank since my CPAP runs on 110 volts. Your responses were very helpful. Thanks to all of you.
Wade

[laknox]

wademartin wrote:
I have a 5th wheel camper with two Exide Stowaway Group 27 Marine/RV batteries wired parallel that powers my 12 volt panel and connected to a 300 watt inverter that powers my CPAP machine, my satellite receiver, flat screen TV, electric razor and cell phone charger when off shore power. To maintain my batteries I proposed to add a 100 Watt Polycrystalline Solar from Grape Solar on the camper roof with a Sunforce 10 Amp Digital Charge Controller. Any comments, suggestions or advise will be appreciated.
Thanks, Wade

Off the top of my head, dump the 12v batteries and go with 2 or 4 6v golf cart batteries. Also, as others have said, 100w of solar isn't likely to be enough to keep you charged up. Besides panels, your solar charge controller is probably =more= important than quality panels. A =good= controller can actually increase charge efficiency upwards of 10%, maybe a bit more, over a "standard" controller. Personally, I'd have a minimum of 1,000w inverter and 200w solar; more, if I could afford it.

Lyle

[pianotuna]

Hi,

Then make her responsible for deploying them and striking them before you roll down the road.

SkiSmuggs wrote:
The DW is allowing no panels on the roof of her fiver. LOL
However, if we were to boon dock in one spot for a few days, I could lay the panels on the roof with stand offs. Or go with two 100w panels for that and keep the suitcase as is for reserve power and portability. It is still up in the air. So many choices.

[2oldman]

camper19709 wrote:
The 100watt may be a little small for your needs.

Yeah. That's a 7 amp charger running a few hours/day.

[SkiSmuggs]

I got a 100w suitcase solar kit with 10w built in controller and have already ordered a 30w Solar30 controller from ebay. I plan to bypass (remove) the built in controller, mount near the battery bank to minimize loss. I will buy a 100 watt panel to combine with the suitcase kit using a homemade stand. I will have the capacity to add a third panel if I want. The DW is allowing no panels on the roof of her fiver. LOL
However, if we were to boon dock in one spot for a few days, I could lay the panels on the roof with stand offs. Or go with two 100w panels for that and keep the suitcase as is for reserve power and portability. It is still up in the air. So many choices.

[justme]

After you determine the watts you need, consider flexible solar panels. Some RV's, especially Heartland products, can be a challenge to install encased panel solar units because they don't have ply wood roofs to anchor them properly. Flexible panels work as well as encased panels and some brands offer better partial shade spec's.

[amandasgramma]

We have 2 140 watt panels and a 2800 watt inverter....with 6 golf cart batteries. We run all that you talk about on the batteries....with exception of the tv. DH does not want to trust running the tv on batteries...he's afraid he'll have to hear me snore during the night if the batteries die. As others said, camping under trees does not work for getting sun power.

[pianotuna]

Here is a simple flow chart.

Budget-->Energy Audit-->Battery bank size-->number of watts-->PWM or MPPT. What ever type of controller is chosen, make sure it has adjustable set points and a temperature probe that is on the battery.

One rule of thumb is between 60 and 150 watts of panels per 100 amp-hours of storage. The smaller the battery bank the higher the wattage needed (per 100 amp-hours). Here is a link to the rather special spreadsheet which includes an energy audit, that N8GS has created to help size solar battery charging systems!

Solar Spread Sheet by N8GS

For a nice explanation of solar, try this link:

Golden rules of solar

For such a tiny battery bank I'd recommend about 270 watts.

[camper19709]

The 100watt may be a little small for your needs. I would go with a 160 or 200watt panel. You can always add panels later. Make sure you get a controller that can handle the watts you decide to buy. Also when you buy new batteries get 2 RV deep cycle batteries.
I would not want to be without my 120watt panel. I can go for days without needing to run the genny. I only run the genny when I need A/C or run the microwave.

[time2roll]

100 watts might be a bit light depending on use. You can add more later if needed so good to go.

Is that a local panel to save shipping or do you want to compare prices?