Is solar worth it?

[Otis]

http://youtu.be/npOCVDVkft4

I just happened onto this video by Tom of FWC, in which he does a nice job comparing and contrasting fridge types. His discussion of power consumption by the 2-way and 3-way is in nice simple language for the non-engineer type (me!) I now know why running my fridge on DC while driving still sucks my camper battery way low. I will likely just run it on gas all the time from now on.

I had FWC retrofit their 100w solar panel and Zamp controller and we are completely satisfied. On my last 3 night outing (lows in the 20s, cool sunny days) the controller read full the entire stay; I have one camper battery, gas fridge, and used lights (led), water pump, and furnace as much as I wanted and didn't seem to ding the charge at all.
For us, solar has definately been worth it.

 

[billharr]

did you wire the fan into the compressor positive so that it only runs when the compressor kicks in?

I wired into the wires to the fridge fan and put in a plug (white) you can see in the picture. for power I ran 12 gage wire to the fridge, yellow plugs to the right side.

 

[longhorn1]

After reading the threads, it appears that the majority of the postings are referring to older model campers. Our camper is a 2014, with 2 AGM batteries, 100 watt Zamp solar, with the Zamp controller and IOTA. When it was installed it was also connected to the truck battery. We have the 80 watt condenser fridge. When we first took the camper out to Indiana State Parks we spent several nights not hooked up to park electricity so we could see how we were doing and that included my CPPAP machine. While in Great Smoky National Park, we had a lot of shade and rain and managed to do fine. We did some driving to bring things back up to full.

I now have the camper stored and covered. I wonder if anyone has monitored how long the batteries will stay charged, during the winter, with all electricity turned off. My thought was that at least once a month, I would pull the tarp back so I could get 1-2 days of solar to re-charge the batteries. Thanks for any advise.

 

[billharr]

I now have the camper stored and covered.

I wonder if anyone has monitored how long the batteries will stay charged, during the winter, with all electricity turned off. My thought was that at least once a month, I would pull the tarp back so I could get 1-2 days of solar to re-charge the batteries. Thanks for any advise.

That is so sad to read.

As far as storing the batteries without solar working. I am a big fan of battery tenders. I have used on my motorcycles for years when I am not riding for a few weeks. Motorcycle batteries are as small as they can make them and cost almost as much as a AGM for the camper.
Costco has the tender of sale for $29.99 on black Friday. Buy one plug it in and forget it for the winter.

 

[longhorn1]

That is so sad to read.

As far as storing the batteries without solar working. I am a big fan of battery tenders. I have used on my motorcycles for years when I am not riding for a few weeks. Motorcycle batteries are as small as they can make them and cost almost as much as a AGM for the camper.
Costco has the tender of sale for $29.99 on black Friday. Buy one plug it in and forget it for the winter.

Thanks Bill. I store that camper at a storage place, so no power. When I retire, I will store it at home on the truck which would lend to the tender. I haven't checked my homeowners rules, but I suspect they will slap my hand if I put a tarp over it on the truck, so I will have to read up on the rules. It was 7 degrees this morning when I got up, broke the record set in 1976. I will have to check the AMPS every couple of weeks and pull the tarp back for a day. jd

 

[PaulT]

AGM batteries are better than the liquid cells at retaining charge in storage. However, you have two built-in options for keeping your batteries fully charged. Both the Iota & the Zamp charge controller will float charge the batteries and also return to absorption mode periodically if there is no discharge from use for some time. This keeps the batteries in good condition. IMHO, the Iota is likely better if you can keep the camper plugged in.

Remember that your gas detector and the Zamp controller both draw some current constantly. Read the FWC manual about the main pull out power switch.

If you see the display on the Zamp at night, it is pulling some current. My Zamp display backlight is always on unless AC power is attached.

I have not been able to get a wiring diagram for the camper other than the minimal one provided for installation. I don't know why FWC can't provide one.

Paul

 

[RC Pilot Jim]

Don,

For new owners of any RV used off the grid it takes time to learn to balance the needs of your 12 volt devices and available electrical energy input.

Recently I bought a Trimetric 2030-RV battery monitor because I wanted to monitor the amperage in and out and know the percentage of full. It is hard to diagnose source of problem with out all the facts.

As an example. Your system may be doing a great job during the day when the sun is shining - however may not be totally filling the batteries. If your daily hourly average amp usage is 5 amps and you have the 2 stock 80 amp batteries the formula is 80 x 2 = 160. 50% usable amperage = 80. 80 divided by 5 = 16 hours battery life . If you are camping in November in Death Valley you would experience 13 hours of darkness giving you a 3 hour reserve. If your batteries are not topped off each day...then after about 3 days your fridge will shut down.....because available voltage will be lower than 12 volts.


Even though you don't say you probably have a Waeco/Dometic compressor fridge.since you purchased your camper in the last 2 years. The absorption type uses 110 volt, propane, 12 volt. They draw 12 amps per hour on battery and will totally kill both your batteries in 13.33 hours

It is possible there is nothing wrong with your solar/alternator battery charging system. The cause of the problem could be the battery operated devices you run on it are drawing more amperage than the solar panels are replacing.

Usage
Repeating what I said above
There is a formula to determine how long batteries last
Your original post says you have 2 aux batteries. If stock FWC they are probably 80 amp hours each or 160 total.

USABLE amperage though is 50% so you only have 80 amp hours usable.

FWC can provide a chart that shows the amperage used by your various devices. Thebiggest users are the fridge and furnace blower. What else are you running? TV?, Digital camera chargers? fan? Lights? radio? Dish ?

Take the total and divide it into 80 (total hours available) will give you the number of hours before your devices stop working.

Most Devices won't run much below 12 volts. They Auto shut down to protect the circuitry.

Solar panels
Your original post doesn't say how many you have.
If it is one 100 watt it may not be large enough to run your devices and charge the battery.

Reason: Angle of the sun and shade.
Angle of sun:
On June 22nd sun is directly overhead. If batteries are at 60% charging rate will be 5.7 amps. In December might be 2,5 amps because you can't tilt the panel towards the sun.

Shade
If you park in the shade panel loses 70% or more of its charging ability. Reason many of us carry a small portable panel in summertime.

SurePower Separator
Purpose is to protect the truck battery. If voltage in the camper battery drops below 12 volts, SurePower will disengage the alternator to the camper battery. Only solar or shore power charger can charge battery back up to 12 volts which than brings alternator back on line.

Truck alternator
3 hours driving is not enough time to top off your batteries. You probably need at least 6 hours.

What is the total average amp draw of your 12 volt devices?

What are the conditions you camp in?

 

[Kispiox]

I just wanted to say that I find solar to be very useful. I have 100w, w/ two AGM, and when the batts do get to the end of their lifespan I will delete one from the system. The storage just isn't needed with all LED and 3way absorption refer. Case in point,.. I left my camper on jacks in a storage yard in direct sunlight, windy conditions in 90deg daytime temps for two weeks. I left the "refer fan" switched constantly on with with the refer on gas with a completely full bottle of propane. After two full weeks I returned from the city and the propane was almost gone. I cut it really close, one more day and I would have had a problem. The batteries, however were completely charged. After putting the camper back on my truck, that evening I enjoyed a salmon dinner from the freezer. Solar is definitely worth it, regardless what type of refer system.

BTW, Good video Otis!

 

[esimmers]

I'm responding to the question from longhorn1 about how long a battery will stay charged during storage.

IF you start with a fully charged battery, and IF you pull the fuses at the battery so that there is absolutely no drain on the battery, THEN it will stay well more than 50% charged for several months (5 months in my case), will not be damaged by freezing temperatures, and will easily top off when you're ready to use the camper in the spring.

 

[DonC]

wow - I appreciate all the conversation and information here. I'm sure FWC monitors this site but I sent them a link to this thread. As was said upthread, you should not have to be an electrical engineer to make this stuff work.

It is hard to answer all of the questions, either because my camper is at American RV, or because I don't understand them technically. But some of the basics I may not have provided:

- 2012 Fleet with compressor fridge (small), 2 camper batteries, solar panel (80W? or whatever they offered at the time), furnace, LED lights. I explained my typically usage to FWC at purchase and this is what they recommended would meet my needs.

- 2006 Tundra - stock, 60k miles, excellent shape. Install done by FWC.

- Before each trip I plug into shore power and completely charge. Turn on my fridge so it cools down during the night while plugged in. Before leaving all food/drinks put into fridge are pre cooled.

- Typical 4 - 6 hour drive to my designation - Death Valley, east side of Sierra.

- Never camp in a camp ground, no shore power available where I camp. If I can see someone, I move and camp somewhere else. I have 4x4 so usually go off to a side road. Usually camp in areas with full sun.

- Usually use the stove once each evening for 5 - 10 minutes, only use the LED lights for less than 5 minutes per day first 2 nights, then headlamp after that.

- Have never used the 12v plugs inside the camper, unfortunately... I use an inverter while driving during the day to recharge laptop, camera batteries, etc.

- Usually drive 2 - 3 hours per day to go to various hiking or photo sites. Usually park in full sun.

It is clear that my title should have been "is solar and a compressor fridge worth it". Those with solar and a 3 way fridge seem to have no problems with energy use.

 

[Riverrunner]

It seems most of the folks that have good luck with solar are lucky enough to live where the sun shines more often that not. I'll stick with my 3 way even with it's drawbacks. After a lot of research on this topic, no it's not really worth it for me given where I live and camp. I can do a 3 to 4 day trip with no power issues and one battery if I pay attention.

 

[Captm]

Don, sorry to hear of your troubles. Your system as stated is basic and should be problem free. There is not much to trouble shoot - alternator output, wire (size) from between truck system and housed battery, connections, wire (size) between battery and solar, battery and fridge. Maybe 45 minutes to trouble shoot and a full day to replace the minimal gage wire, crimp connectors, frame grounding, etc. What has your down time been so far?
Attached are samples of what is stock on the Fleet. The single black and red wires in the ceiling box photo are for the solar connection . The 10ga sheathed wire in the second photo is what connects from the camper batteries to your truck system.

 

[SunMan]

I can do a 3 to 4 day trip with no power issues and one battery if I pay attention.

x2. We are rarely in once place for 3 or more days.

 

[Ramblinman]

It seems most of the folks that have good luck with solar are lucky enough to live where the sun shines more often that not. I'll stick with my 3 way even with it's drawbacks. After a lot of research on this topic, no it's not really worth it for me given where I live and camp. I can do a 3 to 4 day trip with no power issues and one battery if I pay attention.

X2 well said

 

[craig333]

I hope you/they have checked all the FWC connections. These things are notorious for bad grounds and I'd definitely not impressed with the connectors FWC uses (never seen what ATC uses).

 

[RC Pilot Jim]

Don,

As a retired computer tech I was taught to look for a simple answer (98% of time problem was bad cable).
Look for the simple answer...especially since the factory and the dealer checked out your system and found nothing wrong with it.

I don't think your solar panel is large enough to run the fridge and top off the batteries. My portable 60 watt puts out 3 amps max and the 100 5.7...in June. Camping in desert in fall-winter, Roof Panel is putting out 50-60% of rated charge.The 60 watt is portable and aimed at the sun..and is barely enough to run the highly efficient Engle top loader compressor fridge (avg hourly use 1.2 amps)

How much amps is the 80 watt rated for?

Is 80 watt a portable? or mounted on the roof?

How many amps does your compressor fridge draw? Guessing Probably around 3-4?

If the 80 watt is putting out 4 amps in June its putting out 2-3 in winter (mounted on the roof)...barely enough to run the fridge..not enough to top off the batteries thus you run out of juice.

If portable and you aim it at the sun than it should put out max amps still you are probably using more amps than solar is replacing.

Buy a larger panel - 100 - 150 watt.

 

[DonC]

RC Pilot Jim - I can't answer all of your questions at the moment, but the panel was installed by FWC on the roof. Everything is a factory install. If my batteries should be recharged in 2 hours of driving each day (as Tom says in his video) there should theoretically not be a problem. But they don't get topped off in 5 hours of driving in full sun - there were at 11.7v after driving home from Death Valley last week.

Are 2012 solar systems from FWC simply undersized?

How difficult is it to remove the current panel and install a new larger one? What does it do to the one piece roof?

 

[RC Pilot Jim]

I have a Waco CR 65 with 100 watts on the roof and a 120 watt solar in a bag. I just did a trip down 395 to southern Cal. I only used the solar in the bag on the 3rd day to see if it would raise my volts, still above 12v. I know if I did not have full sun I would need the 120 watt panel to stay in one place more than 3 days. I had propane and it did not just work for me. Frozen food, flame blowing out and just stopped working for a few hours.

How many amps does your fridge draw? Are you getting enough charge to fill it and charge the batteries?

 

[jha6av8r]

RC Pilot Jim - I can't answer all of your questions at the moment, but the panel was installed by FWC on the roof. Everything is a factory install. If my batteries should be recharged in 2 hours of driving each day (as Tom says in his video) there should theoretically not be a problem. But they don't get topped off in 5 hours of driving in full sun - there were at 11.7v after driving home from Death Valley last week.

Are 2012 solar systems from FWC simply undersized?

How difficult is it to remove the current panel and install a new larger one? What does it do to the one piece roof?

If you're driving and the batteries aren't topped off after 2 to 3 hours something is wrong between the truck and the camper batteries. My Grandby is a 2012 also. We picked it up on December 21st. At the time the solar panel was 90W. It doesn't keep up completely but I don't worry about my batteries sitting for a 3 or 4 day weekend and not driving much. However I expect my batteries to be full after driving for 3 hours.

 

[Captm]

You can lower the draw on the batteries by minimizing the on/off cycling of the refer with 1. extra insulation and 2. directing the flow of air thru the coils. In my case with the countertop installed the fan (located between the coils and condenser) draws all its air through the aft vent only. The air continues thru the coils, exhaust past the condenser, and is forced out the forward vent. A fan in a open box, your basic RV industry install, is cost effective for them but cost you money everyday you use your fridge.