Minimal solar

Albertg

Member
Looking for a minimal solar system and wonder what I may need. I really only need power to run my water pump and some LED lights for two people. If I understand correctly my elec. tongue jack and slider will run off of my truck power when hooked up so if my battery is low I can still pack up. I also think i need some power for my electronic ignitions to work even if they are already on when the power is depleted.
I have a 50 db generator that I can use when not in a campground as needed but I think I need a solar option.
Thanks for your input.
Al
 

Go-Fly

Well-known member
Sounds like you just want to keep your battery charged. Take some time and figure out what your power consumption is per day. Match a system that will keep your battery full. I like to use a company named Renogy. They do a kit that has everything you need. Gave you a link below. I now have a 600 watt system from them that gives me all the power I want. It's 8:40 at night and I'm sitting here with the TV on, working on the computer and all the lounge lights are on. All off of batteries charged during the day. On a sunny day the panels will run our crock pot all day and still charge the batteries. Don't cut yourself short. It's free power for the next 20 years. I have made and used over 500Kw of power to date.



https://www.renogy.com/products/solar-kits/
 

Oregon_Camper

Well-known member
Here is a link to a video I did for a 120w portable solar system from GoPower. We have 540w of solar on the roof, but this little guy does a GREAT job of adding power when we're camping in locations with trees, as I can move it into the sun...hard to move RV into sun. :rolleyes:

https://youtu.be/-gi0JZZVizE
 

LBR

Well-known member
$150.00 at Harbor Freight will buy you 4 - 25 watt panels that set on the ground, complete with all wiring and adjustable charge controller. A 100 watts will do what you requested.
 

RossRagan

Well-known member
Just purchased a Renogy portable 100w suitcase kit/system and hooked it up last night to verify functionality. If it turns out 100 doesn’t quite cover my needs I can add another 100W panel without upgrading the controller.


Sent from my iPhone using Tapatalk
 

RossRagan

Well-known member
Ah...I see. You must have the newest model that uses Solar and Moonlight. Very nice. :)



Yup...Moon-o-crystalline
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RossRagan

Well-known member
I mentioned my Renogy suitcase solar panel kit previously. I just set it up in full sunlight and it is indicating 5.9 amps, 4.8 Ah into 13.9V at 2:45PM. That is pretty much in line with its specifications. It remains to be seen if that kind of solar support will allow me to dry camp without hook-up for any period of time. It dropped down to 3.4 amps when a thin cloud drifted over.
 

Silverado23

Iowa Chapter Leaders
I mentioned my Renogy suitcase solar panel kit previously. I just set it up in full sunlight and it is indicating 5.9 amps, 4.8 Ah into 13.9V at 2:45PM. That is pretty much in line with its specifications. It remains to be seen if that kind of solar support will allow me to dry camp without hook-up for any period of time. It dropped down to 3.4 amps when a thin cloud drifted over.

That is roughly 60-80 watts per hour. The RV Fridge alone will use around 300 watts per day of 12v power while using propane. Chances are you will use around 800-1000 watts per day or more. Also your panel will have a peak power that as you found out will drop quickly with cloud cover and lower sunlight levels such as morning or late afternoon.

Depending on how your panels charge your battery, It may not provide full output without higher power consumption.
 

Albertg

Member
That is roughly 60-80 watts per hour. The RV Fridge alone will use around 300 watts per day of 12v power while using propane. Chances are you will use around 800-1000 watts per day or more. Also your panel will have a peak power that as you found out will drop quickly with cloud cover and lower sunlight levels such as morning or late afternoon.

Depending on how your panels charge your battery, It may not provide full output without higher power consumption.


Why does the frig use so much power when on LP?
 

RossRagan

Well-known member
That is roughly 60-80 watts per hour. The RV Fridge alone will use around 300 watts per day of 12v power while using propane. Chances are you will use around 800-1000 watts per day or more. Also your panel will have a peak power that as you found out will drop quickly with cloud cover and lower sunlight levels such as morning or late afternoon.

Depending on how your panels charge your battery, It may not provide full output without higher power consumption.

Good info, thanks. Sounds like 300 W worth of solar panels would be minimum to hope to be self-sustaining with Refer, overnight furnace (55 degree setting), waterpump, minimal LED lighting. My pair of 175 A-Hr 6V Golf Cart batteries should be sufficient if I can get sufficient solar to charge them during the day. Coincidently, the Solar Charge Controller that came with the suitcase can handle about 300W...any more and I'd need to upgrade the controller also.
 

Silverado23

Iowa Chapter Leaders
Good info, thanks. Sounds like 300 W worth of solar panels would be minimum to hope to be self-sustaining with Refer, overnight furnace (55 degree setting), waterpump, minimal LED lighting. My pair of 175 A-Hr 6V Golf Cart batteries should be sufficient if I can get sufficient solar to charge them during the day. Coincidently, the Solar Charge Controller that came with the suitcase can handle about 300W...any more and I'd need to upgrade the controller also.

Your pair of Golf cart batteries are a good start. That has a capacity of 12V x 175A of 2100 watts. With about 1000 watts readily usable (50%).
To recharge this capacity with your panels you would need 10 hours or more of full sunlight using 100 watt panel.
300 watts would probably recharge your capacity in about 3.5 hours of full sunlight.

Higher wattage panels would offer more reserve charging capacity in case of lower sunlight levels and/or higher daytime usage.

Depending on your power needs, You may need more battery capacity and/or charge capacity.

Your Furnace will be a pretty good portion of load overnight but may run your batteries down faster than can be recharged in the morning.



My system has 3 - 12v batteries for a total capacity of about 4100 watts and have around 2100 watts available (50%). I have 765 watts of fixed (flat flexible panels on curved roof) panel capacity and my system is usually recharged in about 3 hours in the mornings. However, On dark rainy days it could take more than one day to fully recharge. My usages is around 1000-1200 watts per day. Mostly lights, water pump, furnace and fridge (All 12v power). I have about 2-3 days usage capacity without recharging much.
 

RossRagan

Well-known member
Ordered another Renogy suitcase 100W panel thinking I would expand to 200W. Found out the suitcase without the controller has the MC4 connectors reversed on the solar panel output wires compared to the original solar panel kit that I purchased which included the charge controller. My intent was to just get one of the MC4 "Y" connector pairs and just connect both solar panel outputs together and then run that into the original charge controller (controller is rated at 20 Amps which means that it could handle up to 3 suitcase solar panels). Since the the connectors are not the same polarity that wouldn't work so I called Renogy to find out if maybe the new panel had been wired incorrectly. The service tech said it was not and that the solar suitcase Kit was not intended to be expanded. He then said that I should have purchased two solar suitcases (no "kit") and then purchase the controller separately if I wanted to double up the inputs. He said any modification of the panels (doubling up the input to the kit is considered a modification) would void the warranty on the solar panel.

It must be in the small print somewhere...oh well....I'll have to make due. Still debating if I want to make an adapter to change the polarity of the MC4 output connectors on the new panel and just proceed as originally planned.
 

CarterKraft

Well-known member
What about just buying a Y connector then reversing the one for the new panel and installing that in-line. No mods to the original suitcase or the new panel only the low $ Y connector?
 

LBR

Well-known member
Ordered another Renogy suitcase 100W panel thinking I would expand to 200W. Found out the suitcase without the controller has the MC4 connectors reversed on the solar panel output wires compared to the original solar panel kit that I purchased which included the charge controller. My intent was to just get one of the MC4 "Y" connector pairs and just connect both solar panel outputs together and then run that into the original charge controller (controller is rated at 20 Amps which means that it could handle up to 3 suitcase solar panels). Since the the connectors are not the same polarity that wouldn't work so I called Renogy to find out if maybe the new panel had been wired incorrectly. The service tech said it was not and that the solar suitcase Kit was not intended to be expanded. He then said that I should have purchased two solar suitcases (no "kit") and then purchase the controller separately if I wanted to double up the inputs. He said any modification of the panels (doubling up the input to the kit is considered a modification) would void the warranty on the solar panel.

It must be in the small print somewhere...oh well....I'll have to make due. Still debating if I want to make an adapter to change the polarity of the MC4 output connectors on the new panel and just proceed as originally planned.
Seems really odd that they would wire a kit panel opposite from a non-kit panel. Even so, you could cut one plug off, flip it, and resolder it back on, effectively reversing the wiring polarity, right?

I had bought 2 complete 100W kits thru Harbor Freight for my Zamp connection and connected them with a hub. After awhile, I got tired of the clumsy looking hub, so bought a pigtail and soldered up my own "Y" to cleanup the looks.

So would this hub work for you? One can plug in up to 8 panels, then pigtail from the hub into the controller.
84d324defc814dd4d3d19e3276d97f1f.jpg
 
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RossRagan

Well-known member
Seems really odd that they would wire a kit panel opposite from a non-kit panel. Even so, you could cut one plug off and resolder it back on, effectively reversing the wiring polarity right?

I had bought 2 complete 100W kits thru Harbor Freight for my Zamp connection and connected them with a hub. After awhile, I got tired of the clumsy looking hub, so bought a pigtail and soldered up my own "Y" to cleanup the looks.

So would this hub work for you? One can plug in up to 8 panels, then pigtail from the hub into the controller.
********************************
Your reply started me thinking and I realize I was mistaken...The kit actually had the solar panel wired directly into the controller (see diagram below from manual). I had disconnected them from the controller and wired them into the MC4 connectors like the ones used on the kit's output wire (which is made to connect to a wire cable with alligator clips on one end to connect to the battery). I matched the wire color and polarity of the connectors that I put on the solar panel output with wire color and polarity of the controller output wires, so I guessed wrong...it wasn't Renogy changing the polarity. I made the changes when I first received the kit, planning for expansion but that was a couple of months ago...Sorry for the confusion.

Renogy.jpg

I have MC4 connectors here that I bought in preparation of adding another solar panel, so I can just switch the connector on the kit panel to match the factory polarity on the standalone panel and I will be able to parallel them up. In case you hadn't figured out already, I wired in a pair of wires to the solar input to the charge controller that have MC4 connectors that mate with solar panel output connectors. I'll need to change those as well to keep wire colors matched.
 
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