Is solar worth it?

[dsrtrat]

It's all about watts/amps. Checking voltage will give you a rough idea of what you have in battery charge but it depends on many factors. Is the battery under load or resting? Different voltage readings. Is the solar charging the batteries? Different voltage. Cold or hot out, different voltages.

The green yellow red panel lights are just about useless in showing the charge state, you need to be able to log the amps you are using over the course of a day.

You need to see both watts in and watts out.

Nameplate draws on appliances are often inaccurate. Poor installation will cause the fridge to run more than necessary. The wiring in these campers is the weakest link.

Check the voltage at the batteries and then check it at the fridge, you can see what your voltage drop is.

Driving should charge your batteries, check your trucks gauge, it should read lower when charging and move above 14 volts when they are charged.

If they aren't charging the problem is often in the wiring from the truck to the camper, bad connections at the plug, too small a wire from the truck.

The 10 gauge wire from the truck to the camper is marginal to charge one battery much less two discharged batteries.

My 65 watt panel keeps up with my Engel 45 fridge and other minimal draws, runs the furnace overnight and still is above 12 volts in the AM.

Remember that there are losses throughout the system, you only have about 50% of the total amps available in your batteries before drawing them down lower than is good for maximum battery life.

Add up the other losses due to voltage drop and temperatures and your reserve drops even lower.

Dsrtrat

 

[norcalhawk]

DonC....I think solar is a good thing. Surely FWC installed compatible components, i.e., Panel size (watts), controller and wire, etc. Could your Refer be defective? What size is it? What size solar panel? That said, I am replacing my 3-way absorption refer with a compressor type...my luck with propane has been rocky to say the least.

 

[SLEDAWG]

DonC. For the first two years with my Fleet with 2 batteries, I suffered the same problem you describe. I have a Fleet on a Tacoma with a 130amp alternator. After 3 days of camping and 6 hours a day driving my batteries were dead. Multiple calls to FWC resulted in no solutions and comments from Brenda that it is "not an unusual problem." Well...that was frustrating and I too wondered why FWC install their product knowing it wouldn't recharge. Hmmmm...

Before FWC or everyone gets spun up, I am overall happy with my Fleet...not so much with the electrical design.

So, being an electrical engineer I did a complete analysis of the system. I determined there were two flaws to my electrical system to my Fleet. The first was the isolator. The isolator installed in the Fleet did not operate correctly and it ran extremely hot. I resolved the problem by shorting the FWC installed isolator and installing a 200amp rated isolator that I control manually with a remote switch. The second major flaw to the electrical system is the wire gauge provided by FWC is insufficient gauge provide amperage required to charge off of the alternator. I added a 6 gauge "hot" and ground wires along with the appropriate fuses. 8 gauge would be sufficient. All of this solved my electrical problems and the two AGM batteries now completely charge after an 2 hours of driving. I also ended up adding a 100W solar flat panel with a mppt controller and digital monitor that keeps up with everything if I don't run the engine. I have a Fully loaded fleet with a 60L Ac/Dc Compressor Fridge, LED lights and I rarely run the heater.
I suggest a couple of things to check:
1. With the engine running, are the 4 "idiot lights" on the bat monitor illuminated? If not, the isolator is not closing. If you have a volt meter, check the voltage on the engine battery and then check your camper battery. If there is more than 1V drop....you are not charging. BTW the battery monitor lights are useless...you can be down to a 50pct battery capacity and still be read 3 or 4 idiot lights.
2. Find the battery isolator and check the voltage on both sides of the isolator. With the truck running, the isolator should close and the voltage should be less than .5V across the terminals.
3. Find out the amperage of your truck alternator....if it is less than 80amps it will have a difficult time keeping your camper batteries charged.
I am overall happy with my FWC...once I fixed the electrical system. Suggest you read the plethora of posts on WTW solar and batteries...lots of good data. Hope you work it out. I am am finally "electrically stress free with my FWC!"

FWC: I suggest you add to your "Truck fit" a discussion on electrical requirements for the truck alternators and highly recommend you increase the wire gauge for FWCs.

 

[DrJ]

Sledawg,
What battery isolator did you use to replace the stock one?

 

[esimmers]

Coming to this discussion late and having read much which speaks my mind already, I can only say that RV solar systems are still "cutting edge" technology for most people. Unless you have a way to measure each of the real-time loads on your battery, and make sure your battery is getting fully charged, you are shooting in the dark when it comes to trouble-shooting.

Those who need their teenage grandson to help them figure out their smartphone must plan to spend a lot of time learning a lot about electricity in general and RV solar power in particular. I know; that was me.

The TriMetric monitor that has been discussed is a great tool but it's expensive, not simple to install and somewhat difficult to understand.

I have a TriMetric and was really surprised when I used it to measure overnight loads. The water/battery meter and the gas alarm draw about .1 amp, my rear porch light (LED) draws .25 amp, the 3-way Dometic RM2354 refrigerator averages .35 amps when it's running on gas, my CPAP machine draws .6 amp. That's a total of 1.3 amps; that doesn't seem too bad except that when you consider night is about 8 hours long, you're using over ten amp hours of battery capacity (8x1.3) during the night. That's a significant amount; over 25% of the useable capacity of a typical FWC "80 AH" battery like I have in my Hawk.

And this doesn't take into consideration at all the daytime draws from the water pump, ceiling lights or the Fantastic Vent ceiling fan (2.5 amps by itself), cell phone chargers, etc.. By the way, unplug the CPAP machine when you're not using it. Mine draws 1/3 as much power just sitting there turned off as it does when it's on and blowing.

If you're careful and have a friend to help, you probably can measure amp draws at the battery with a pocket multimeter. Everyone ought to have one in their camper toolkit to check voltages, fuses, batteries and low-load amp loads under 10 amps or so.

Good luck. Think of it as an adventure; it's actually pretty interesting. Before long, you'll know more than the $80/ hr experts.

 

[NorCalSteve]

My first issue with the charging system in my Hawk was the 30 amp "auto-resetting" breaker, by the battery, was continually tripping (it was warm to the touch and I could hear it clicking and clicking). I replaced both the one by the battery separator and the one under the hood with a 50 amp breaker that has a manual reset. My truck has a 100 amp alternator. Neither one has ever tripped.

My battery in the truck is in the front right so the wires to the camper go from the front right to the firewall, across the firewall, under the truck, into the pickup bed, into and back across through the camper to get to the camper battery. I figured this was about 20 feet. So I decided to run the wires straight back and also upgraded the wires to 6 gauge, like Sledawg, I also left the existing #10 wires from FWC connected since they were there. I had to add some heat protection at the exhaust manifold because of the proximity of the new wires.

Since I have a three way fridge, I ran a pair of 8 gauge wire directly from the battery to the refrigerator so it would operate better on DC. The voltage drop on the wiring through the fuse box to the refrigerator was way to high. I have driven eight or more hours with the refrigerator on DC and it worked great. But, since there is always a chance I might forget to switch back to LP gas (again), I usually just let it run on LPG most all the time these days. Propane is pretty inexpensive.

Solar charge controllers are all a little different so it is hard to tell someone what they will see on their setup. With a good summer sun overhead and a camper battery that is not completely charged, I will get over 14 volts measured on my Camper batteries. If the battery is charged, it will drop to somewhere around 13.4 to 13.6 volts. My battery charged with very little connected to it, is about 12.8 volts,

Another experiment would be to start the car at night or with the solar panel covered and check the camper battery voltage with the engine running and not running. If the camper battery voltage comes up into the 13 or 14 volt range with the engine running, the truck is charging the camper battery. If the truck is trying to charge a fairly dead battery in the camper, the measured voltage at the camper battery could be a volt or more lower than the voltage measured at the truck battery. This difference in voltage is a loss of charging ability. And this is why myself and some others have beefed up the wires between the truck battery and camper.

Not sure any of this helps but it might give you a couple of things to take a look at. It does seem to me like something is not right with your setup.

Steve

 

[craig333]

I know I sure learned a lot. My off the top of my head calculations turned out to be wildly inaccurate. I knew the truckfridge wasn't the most efficient fridge but hey, I have a big battery and 100w of solar. Its enough, in ideal conditions. Middle of summer with no shade it covers my usage, barely. I pooh poohed the gain from mppt controllers, not worth the extra cost when I'll have plenty anyway. The trimetric and others are nice but do I really need one? Well yeah. My guesses aren't very good. Its expensive but down the road when I can afford it I want the trimetric, another 100watts of solar in addition to the portable panel (nice but you need to be nearby to move it into the sun) an mppt controller and the smart controller for my fridge. Yes, you can go cheap for a weekend but when you try and push it it doesn't work. Either that or go back to using an ice chest and I hate wet food.

I don't doubt I've damaged my expensive batteries running them too low.

I'm also not convinced and isolator is even necessary. I know my batteries are charging when I'm driving. I do need to add a larger gauge wire (and since I have the wire I have no excuse for not getting that done). But I have two batteries just for starting the truck and even when I have them in parallel (most of the time) I've never had an issue with starting even at 11.5 volts (worst I've gotten them to).

Right now my camper battery is at 12.5 sitting in the driveway. I don't think its getting much solar at all (fridge is off for the year, just the alarms running).

Maybe I'll do the trimetric (or similar) before I do any upgrades. Should make it easier to which upgrades are most efficient.

 

[NorCalSteve]

I just saw esimmers' post and it reminded me that I had just finished looking at meters. Getting a meter that can measure both voltage and current/amps is a great item to keep handy. I use mine often. The best ones, although more expensive can measure amps just by clamping around the positive (only) wire. Otherwise, measuring amps is kind of a pain. There are a number of these meters available but you want to make sure it can measure DC Amps. Doing a search on amazon brought up this one. Much cheaper than the one I bought although the one I bought "might" be more accurate at lower amps.

Steve

 

[SLEDAWG]

Dr J:

I used the PAC PAC 200 - http://www.amazon.com/PAC-PAC-200-200-Amp-Battery-Isolator/dp/B000CEBXRS. My measurements show negligible voltage drop and resistance.

I added a rocker switch in the cab to manually control the isolator- http://www.amazon.com/Daystar-KU80011-Light-Rocker-Switch/dp/B001GH1PU0/ref=sr_1_1?s=automotive&ie=UTF8&qid=1416203036&sr=1-1&keywords=rocker+switch&pebp=1416203043428

I also added a remote voltage monitor in the cab off of my alternator and the camper batteries so I know I am getting a good charge. Bottomline: I am no longer guessing/hoping if the camper batteries are getting a charge while I am driving. (0.2V drop from the alternator to the camper batteries) With the solar panel and alternator combined, I run between 13.5V to 14.5V. Cold beer, wine and steaks are the norm now in any weather.

I left the FWC isolator in place and moved the connectors to one pole. For the 6 gauge wire, I ran it from the PAC PAC 200 through a 50A fuse direct to the camper batteries. Make sure you add a 6 gauge ground wire off the negative side back to the frame to ensure you have a good circuit for the amperage. The heat generated by the FWC isolator mounted in an enclosed storage compartment just didn't make sense to me. I feel much better without that isolator to worry about in the camper.

Craig333: I recommend an isolator. When you start your engine, the starter pulls a significant load (amps). By not having an isolator, you risk damaging your refer and other electronics in your camper by the repeated voltage and amperage drops. Just my perspective.

I ended up installing the following solar system for those who care. Yup...it cost a some $. But not having to sweat power has made me a happy camper! I still press the "idiot light" button occasionally for amusement.

http://www.ebay.com/itm/Semi-Flexible-100-Watt-Solar-Panel-12V-High-Efficiency-Sunpower-Marine-Rated-/141374996655?pt=CPUs&hash=item20ea9b40af

http://www.ebay.com/itm/Tracer-20A-12-24V-MPPT-Solar-Charge-Controller-2215RN-/131250826009

http://www.ebay.com/itm/Tracer-MT-5-Remote-Meter-/141470712269

 

[Kispiox]

I left it on gas and went fishing......

 

[Tomas Tierra]

Did you catch?

 

[deethe]

is the issue that the ventilation fans are not on a thermostat and therefore run all the time draining the battery bank?

 

[ntsqd]

I put two fans on t-stats in the upper opening. Worked fairly well for our Utah trip this Oct. Unfortunately my t-stat temperature guesses were too low and with my on/off switch they would've run all day. Even those 170mm "computer" fans were less than an amp each, but I still don't think that they need to run that much. Were it that I could recall what temp I chose.....

Going to guess right around 100°F. I think now I'd go with something in the 120°-150°F range.

 

[rotti]

I left it on gas and went fishing......

If I was in the ordering process and picking out my options and I read through this thread I would have second thoughts about solar. You shouldn't have to be an electrical engineer to use solar.

Guess I was lucky.
I spent $269 on a solar suitcase, plugged it in and it worked great.

 

[billharr]

I have only a top vent on my DC Fridge. Did add a computer fan only 0.2 amps. I wired to the fridge so it runs anytime the fridge runs.

 

[Captm]

Bill does the fan on your fridge exhaust past the coils and your fan mounted at your vent exhaust as well ? Looking at your set up I am wondering where your make up air is coming from. One of the fridges that I have is very similar to yours with the exception that the fan and coil are turned so that the fan draws from the left side of the unit past the coils and then the condenser.
Tim

 

[billharr]

Bill does the fan on your fridge exhaust past the coils and your fan mounted at your vent exhaust as well ? Looking at your set up I am wondering where your make up air is coming from. One of the fridges that I have is very similar to yours with the exception that the fan and coil are turned so that the fan draws from the left side of the unit past the coils and then the condenser.
Tim

The fridge fan blows through the coils, toward the computer fan blowing out of the camper. Air can come in to the right of the fan and from under the fridge from inside the camper.

 

[Ramblinman]

If I was in the ordering process and picking out my options and I read through this thread I would have second thoughts about solar. You shouldn't have to be an electrical engineer to use solar.

Guess I was lucky.
I spent $269 on a solar suitcase, plugged it in and it worked great.

Same my solar suitcase worked great for the first trip and then died. They made a quick exchange for. New one. We will see how the new one works. I am not very optimistic.

FWIW, I am considering just swapping out the second battery I have under the hood when the camper battery dies. Or stick with Generator as it is more reliable (gasp!). And mor versatile. Simplicity is king.

 

[deethe]

I have only a top vent on my DC Fridge. Did add a computer fan only 0.2 amps. I wired to the fridge so it runs anytime the fridge runs.

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

 

[deethe]

this sounds like an electrical drain (short) somewhere in the wiring systems.

maybe test all the 12v circuit breaker fuse taps for continuity to ground shorts with an audible voltmeter.

the house battery Ah total maybe too small for the daily loads to recover from deep discharge to full charge with the array size?
(FWC doesn't really link array size with load options when selecting the PV system- sort of a starter kit really.

i'm installing a 390w array on an mppt controller to a 2x12v 140ah bank. the array is calced to provide ~138Ah/day and the bank will have a 2 day capacity on my estimated demand of 140Ah'day.

there's alot of wiring in these campers, i'd start with the voltmeter- & be curious to know what troubles were found the first two times