Solar vs. Generator

[cyberrick1]

This is our first year with our 2018 Rockwood GeoPro G19FBS and we love our trailer. However, we are finding that our batteries (2 12V deep cycle marine), don't last as long as we hoped they would. We are using a CPAP all night, sometimes the furnace, fridge, and I'd like to use the TV. Of course this isn't an issue when we are at a KOA, etc. We like going to the National parks and other campgrounds but are afraid we can't stay longer than a couple of days.


So we are considering either a generator or solar panel. The TT is pre-wired for "Go Power" solar.


We feel the solor direction would be the cleanest and quietest solution but I'm concerned about the price difference. We just want to be sure we are good neighbors while we camp and still be able to allow my wife to use her hair blower in the morning and watch some movies at night, etc.


What do you think?

[Flybob]

First off do you really have deep cycle batteries or the general purpose marine batteries (labeled deep cycle)? Then you need determine your daily 12V current demand. A good battery monitor will help here. Next you need to think about where you camp ( full sun or shade, generator restrictions). The pre-installed solar prep will most likely not meet your needs as it generally is just some minimal wiring and connectors. Also remember you can not count on sun every day, there are some solar applications that provide amount of usable sun in various locations. Best to get all the data before spending any money.

[Duckogram]

I think your expectations are not realistic. Solar is to recharge your batteries i.e 12 volt. Generator is to produce 120v AC power. The hair “blower”/ dryer is a 120v energy pig appliance. To run that you will need a bank of batteries and a fairly large Inverter. Then pray for a whole lot of sunshine.

[SlowrideHD]

We carry a Honda 2000 inverter generator with an adaptor I made for an extra external fuel tank. It is extremely quiet and very frugal on gasoline.

[Cypressloser]

We started with solar about 8 - 9 years ago and always had a backup generator on board but we used it so little that we felt it was a waste of money, space and weight. We do keep an open mind however and will buy a generator if we run into a situation where we feel we must have one.

With our setup we run the res. fridge on solar 100% of the time regardless of weather, even when we're on shore power. On a good day we turn the water heater on electric and even do laundry sometimes when we feel naughty, yes we use the dryer too - and the hair dryer, microwave, tv, etc.. Only caveat is, no AC as it runs the batteries down to fast and the huge amount of weight of the batteries and the inverter(s).

In your rv it is likely the wire size coming from the roof that dictates how much solar you can install and what solar voltage you want to go with, either PMV or MPPT. After that you need to figure out what your energy requirements are, we use around 150 - 250 AH per day and our system can handle it when we adjust our consumption according to the amount of sunshine we get. We have 6 Volt AGM batteries (5 years old now), not because I'm too lazy to regularly check the water level in the batteries but because they don't off gas and will never be the cause of corrosion that you'll find on vented lead acid batteries, we have one 1000 Watt inverter dedicated to the fridge and a 3000 Watt inverter/charger when we need more power.
As far as cost goes, you can compare a good solar setup to a built in Onan gen set and with the batteries you have right now and the need to power a CPAP machine though the night plus furnace (occasionally) you need to upgrade the batteries anyway to true deep cycle (golf cart type) batteries.

[ScottBrownstein]

You will not do what you want with 100 AH of usable capacity. Furnace and CPAP will use it all and solar cannot be counted on except for over the long average. You would need at least 500 watts of solar and a good controller. You will need more batteries as well. Even if yours are deep cycle, it only give you a little more than 100 AH...if the units are fully charged.

A generator will allow you to run heavy use items, but you will need to run it at least 3 hours in the morning and 3 in the evening to get your batteries up to 80 or 90 percent SOC. Solar will take you the rest of the way. People who use solar for everything generally have more reserve battery power so that they can count on a long term average of 4 days or so.

[TitanMike]

If you want to be 100% covered you'll really need both, solar and a generator.

Example would be the camping trip I just returned from. If I had only Solar to recharge my batteries I'd be disappointed. Campground was so shaded by the trees I wouldn't have been able to keep the panels in the sun without moving them every 30 minutes or so in order to follow what little sun penetrated the trees with enough intensity to generate meaningful amounts of electricity.

I opted for a nice quiet Inverter/Generator (Champion 3500W Dual Fuel) that merely idles along while providing enough power to charge my battery bank with as much as a 56 amp charge rate (from a PD 9260 Converter and monitored with a Victron battery monitor). More than enough to recharge a 240 Ah bank in 4-5 hours with enough power to go another couple of days (based on my needs).

Yes, the Generator/Inverter is fairly expensive (~$1100) but not nearly as expensive as some "Big Name" units.

I would personally only "Go Solar" if I was camping in a climate that could pretty much guarantee me 10-12 hours of sunshine each day. The fact that the OP needs reliable power on a regular basis would just about demand either a much larger battery bank or a more controllable power source like generator.

On the "quiet" note, the Champion unit I have is barely noticeable in adjoining campsites as long as the sites are reasonably spaced. I recently appologized to a neighboring camper for running my generator and he responded that he hadn't even heard it. (what sounds loud while standing next to it is often hidden in background noise 50 feet away).

Final note, I chose a Champion based on previous experience with the unit and not wanting to spend over twice the money for a "Big Name" generator/inverter. There are many units on the market that are just as quiet, reliable, and cost a lot less than the "Big Name" so don't be fooled that spending twice as much will get you unquestioned reliability, yada, yada, yada. As for using two units to meet one's power needs, like an old airplane pilot told me once when I asked about twin engine "light planes", his response was "just twice as much chance of an engine failure". Two units to change oil on and constantly refuel. I just leave my gen/inverter in the bed of my truck and purchased a 25' power cord of the same size as the one that came with my trailer. Overall, saved $1,000.

Others have their own ways and ideas, this is just what I chose for a minimum of hassle and expense. FWIW, my original Champion has uncounted hours on it and has been running reliably since 2005. Only "repair" expense? One spark plug and a couple air filters.

[cyberrick1]

Thanks. We've been looking at the generators and it looks like the Champion brands are also quiet and most cost effective too. Thinking of a smaller 2000W generator as they are just easier to carry and move around.

[TitanMike]

Originally Posted by cyberrick1

Thanks. We've been looking at the generators and it looks like the Champion brands are also quiet and most cost effective too. Thinking of a smaller 2000W generator as they are just easier to carry and move around.

Yes, they are smaller and lighter in weight. As long as they meet your power requirements they're great. I went with the 3500 W unit as it allows me to power the AC, use the microwave, and still provide power for the longest part of battery charging. The absorption stage that puts the finish charge on you batteries doesn't draw all that much current compared to the initial bulk charge but it can be enough to keep a smaller unit from carrying the load of AC and Microwave.

As for weight, yes, the Champion weighs in at around 110# with fuel. I just put a small pickup bed crane (from Northern Tool) in my bed and for a $90 investment and 60# of added weight I don't need to lift anything heavy into or out of my pickup bed. After 75 birthdays I don't feel like lifting anymore. If I'm really lazy the crane is easy enough to use I can load gas containers and propane tanks with no more effort than pumping the handle on the hydraulic crane cylinder (jack). When not in use the crane tucks up against and the side rail of the pickup bed and fits nicely under a hard, folding, tonneau cover.

[Cypressloser]

Cyberrick, if you buy a generator (nothing wrong with going this route) I would suggest you use a stand alone battery charger to charge your trailer batteries more quickly and efficiently. This way you won't have to keep the generator running as long, just make sure you stick to the charging parameters for your batteries.

[TitanMike]

Originally Posted by Cypressloser

Cyberrick, if you buy a generator (nothing wrong with going this route) I would suggest you use a stand alone battery charger to charge your trailer batteries more quickly and efficiently. This way you won't have to keep the generator running as long, just make sure you stick to the charging parameters for your batteries.

Is your stand alone battery charger going to deliver more than 55 amp charge rate? My PD9260 Converter with Charge Wizard starts bulk charge at 55-56 amp and slowly tapers down to a steady 30 amp or so near the end of Bulk Charge. It charges a battery bank about as fast as a Flooded Lead Acid battery should be charged.

Rather than using a stand alone battery charger I'd recommend that the main 12V feed wire between battery(s) and converter be upgraded so there is less than 2% voltage drop across the entire wire. THAT will allow the Converter to charge at a rate it was designed to and also switch modes automatically.

A lot better than hooking up that old gas station "Battery Cooker" then forgetting it until your batteries are boiled dry.

For those who don't want to run heavier wire, just move the converter Module closer to the battery bank and run A/C to it in the new location. I chose to upgrade to #4 AWG and the difference in charge rate was like night and day.

[Cypressloser]

Originally Posted by TitanMike

Is your stand alone battery charger going to deliver more than 55 amp charge rate? My PD9260 Converter with Charge Wizard starts bulk charge at 55-56 amp and slowly tapers down to a steady 30 amp or so near the end of Bulk Charge. It charges a battery bank about as fast as a Flooded Lead Acid battery should be charged.

Rather than using a stand alone battery charger I'd recommend that the main 12V feed wire between battery(s) and converter be upgraded so there is less than 2% voltage drop across the entire wire. THAT will allow the Converter to charge at a rate it was designed to and also switch modes automatically.

A lot better than hooking up that old gas station "Battery Cooker" then forgetting it until your batteries are boiled dry.

For those who don't want to run heavier wire, just move the converter Module closer to the battery bank and run A/C to it in the new location. I chose to upgrade to #4 AWG and the difference in charge rate was like night and day.

Your statement is correct, this is why I included in my post that he stick to the charging parameters of his batteries which has a lot to do with the size and type of the battery bank.

When my battery bank is depleted I can pump 150+ Amps initially (bulk stage) into my batteries without seeing much of a change in temperature, the charger should be adjusted to the batteries, not the other way around. Heck, even my solar panels pump 60+ Amps down at times, as I said it depends on the battery bank. I'm not saying he should hook up a 150 Amp charge to 2 hybrid batteries and let it charge indefinitely but why not charge 2 or more batteries at the max. rate they are designed for for an hour or so when the OEM charger only puts out 50 or 60 Amp. Why else are so many rv owners upgrading to larger chargers? I charged my batteries this way many many times in the past and never had any problems with 'boiling' any batteries dry, keep the fluid level up, make sure the caps vent properly (or better remove them), the battery acid looks clear and not murky, feel or better measure the temperature and use common sense. Now with all this said, it is important on vented flooded batteries to check the water level (very) frequently and equalize / desulphicate the batteries regularly, and I believe this is where WFCO chargers could do a better job.

[rk06382]

Originally Posted by cyberrick1

This is our first year with our 2018 Rockwood GeoPro G19FBS and we love our trailer. However, we are finding that our batteries (2 12V deep cycle marine), don't last as long as we hoped they would. We are using a CPAP all night, sometimes the furnace, fridge, and I'd like to use the TV. Of course this isn't an issue when we are at a KOA, etc. We like going to the National parks and other campgrounds but are afraid we can't stay longer than a couple of days.


So we are considering either a generator or solar panel. The TT is pre-wired for "Go Power" solar.


We feel the solor direction would be the cleanest and quietest solution but I'm concerned about the price difference. We just want to be sure we are good neighbors while we camp and still be able to allow my wife to use her hair blower in the morning and watch some movies at night, etc.


What do you think?

Go Solar

I have six Renogy 100 Watt 12 Volt Monocrystalline Solar Panel (Slim Design) in parallel. Today I generated 1.76Kwh of solar energy & it is cloudy.

If you install solar panels on your roof, they will generate power even when it is cloudy. I have seen 150 watts when it is overcast. If you have to buy a solar charge controller make sure it is the latest MPPT. Which solar charge controller: PWM or MPPT?

I also bought a Victron BMV-712 Smart Battery Monitor to know my bateries SOC. (State of Charge)

[AlaskaErik]

I'd just get an A-1Power 2000 watt inverter generator from Costco. $499.99. It has a three prong twist lock outlet, a 30 amp receptacle that plugs into the twist lock, parallel cables if you ever get a second generator, tool kit, oil and oil funnel. That should run most hair dryers, except for those 1800 and 1875 watt monsters. It will also run everything except your A/C. Get two and you'll be able to run everything, although not necessarily at the same time.