Solar panels

[EricHarmon]

Hi all,

I have a question that I couldn't find a better place for. When you install solar panels onto the roof of an RV, do they automatically kick in if you're connected to electric? For example, let's say you have solar panels and are staying at an RV park in, say, Florida, for three months at the monthly rate (which doesn't include electricity). If the RV is plugged into electric, will the solar panels do all the work until they're exhausted, and the shore power only pick up the slack when necessary, thereby saving money on electricity? Or will the presence of shore power override the solar panels?

[DQDick]

That's going to depend on how your rig is set up. First you need to understand that the solar pannels charge the batteries and then the batteries, thru the inverter, powers whatever you have it set up to power. Under no circumstances do you want to run your batteries down to less than 50 percent. That said, on our old rig we had seven pannels, six golf cart batteries and I had it set up so that when we were parked I had a switch in the breaker box I could throw and then the solar powered most things and the shore power powered things like the AC, water heater etc that you don't run on solar anyway. you also need to understand that that setup cost a lot of money and would never pay for it'self. I just set it up that way to get a little of the money back.

[scottz]

You are mixing apples with oranges. The solar power system is DC, shore power is AC. The solar power system (DC), through the solar controller, simply keeps your batteries (DC) charged. The shore power system (AC), through the converter, does the same thing; keeps the batteries charged plus it powers AC devices. They will not interfere with each other. It is hard to measure, but if you are connected to shore power the converter is keeping the batteries charged all the time so the solar power system will probably do nothing.

Keep in mind, your RV has a mix of DC and AC devices.

The DC devices (most things: lights, water pump, furnace, hydraulic system, etc) run off the batteries which are replenished by your solar power system through the solar controller or shore power through the converter.

The AC devices (air conditioning, microwave; some other things could be either AC or DC; in my unit TV's, ceiling fan, power recliners, etc run off AC) are powered only when you plug into shore power.

Don't confuse the converter (converts AC to DC for battery charging) with an inverter (converts DC to AC to allow SMALL AC devices to run off your batteries). You cannot run high power devices like air conditioners or microwaves off the types of inverters usually found in RV's. With the exception of the residential refrigerator package, an inverter is usually something you have to add yourself along with the associated wiring/controls.

This is a complicated way of answering your question. I doubt the solar panels will reduce your shore power electric bill. If they do, it will be very small and difficult to measure.

[EricHarmon]

Thank you both! I certainly wouldn't buy solar panels to reduce electric costs. I was thinking of them because of an upcoming trip through Alaska, when there will be several days in a row on the road without much in the way of civilization. I didn't even realize they wouldn't power the microwave. So perhaps I'm looking at the wrong thing, and what I would need to look into for those days would be a generator. Apologies for what turned out to be a silly question; I'm incredibly new to this (so new that I don't even have my RV yet; making a list of what I need to buy and equip it with).

[scottz]

Originally Posted by EricHarmon

Thank you both! I certainly wouldn't buy solar panels to reduce electric costs. I was thinking of them because of an upcoming trip through Alaska, when there will be several days in a row on the road without much in the way of civilization. I didn't even realize they wouldn't power the microwave. So perhaps I'm looking at the wrong thing, and what I would need to look into for those days would be a generator. Apologies for what turned out to be a silly question; I'm incredibly new to this (so new that I don't even have my RV yet; making a list of what I need to buy and equip it with).

No problem. I dry camp most of the time and have both solar and generator. I don't run the generator much; if I do it is because I need to run the microwave, air conditioner or charge my batteries because the sun is not out. If I had to chose one, it would be solar.

It is possible to run a microwave from an inverter, but it has to be a big inverter. I think microwaves are about 1500W, so the inverter has to be bigger than that. Of course, you would have to consider how long your batteries would last pulling that much out of them; my inverter is 2000W and I would not do it.

[Mudchief]

There are no silly questions on this forum. This is where you come to learn. Our unit will run everything on solar even the AC for about 5 hours. However for your trip to Alaska what you need is 4 6 volts batteries a good inverter and a Honda 2000 generator to charge up your batteries. Unless you stay off the grid like we do you don't need to invest in solar.

[scottz]

Originally Posted by Mudchief

There are no silly questions on this forum. This is where you come to learn. Our unit will run everything on solar even the AC for about 5 hours. However for your trip to Alaska what you need is 4 6 volts batteries a good inverter and a Honda 2000 generator to charge up your batteries. Unless you stay off the grid like we do you don't need to invest in solar.

You must have a huge inverter!

[PNW Fireguy]

Big inverter and lithium....a nice combination.

[EricHarmon]

Originally Posted by Mudchief

There are no silly questions on this forum. This is where you come to learn. Our unit will run everything on solar even the AC for about 5 hours. However for your trip to Alaska what you need is 4 6 volts batteries a good inverter and a Honda 2000 generator to charge up your batteries. Unless you stay off the grid like we do you don't need to invest in solar.

Thank you! I've got so much to learn, which is why I'm researching all this incredibly early. We're still 18 months away from purchase, but slowly but surely, we've determined our model, our route for the first year, most of the addons that we need to purchase, have visited some RV and truck dealerships, and so on. So much to learn and prepare for!

[scottz]

That's probably smarter than those of us that go into an RV show with no plans to purchase, and leave with an $80k fifth wheel.

[EricHarmon]

Originally Posted by Mudchief

There are no silly questions on this forum. This is where you come to learn. Our unit will run everything on solar even the AC for about 5 hours. However for your trip to Alaska what you need is 4 6 volts batteries a good inverter and a Honda 2000 generator to charge up your batteries. Unless you stay off the grid like we do you don't need to invest in solar.

Mudchief, I'd love a bit more info if you could. I'm on Camping World's web site (only for search capability; not because I'm buying anything any time soon!). I can't figure out if the inverter is built into the generator? I did a search for Honda 2000 and it almost seems like some say they're Inverter generators, though I may not be understanding correctly. I also didn't find a single 6 volt battery (though maybe they simply don't sell them there, I suppose).

I'm seeing a Honda 2000iA generator (as well as a 2200iA so I'm guessing that's the same but just slightly beefier). Is the inverter part of the generator? I'm also seeing sine wave inverters from other companies. I'm totally lost here; I want to do some reading on some recommended products to learn how these pieces fit together and how they operate.

So I guess what I'm asking, if it's not too much trouble, is can you specify the model of the Honda that you'd say is good? As well as a good inverter? And I'll do an Amazon search for 6 volt Lithium RV batteries :-)

Thank you so much in advance...

-Eric

[EricHarmon]

Originally Posted by scottz

That's probably smarter than those of us that go into an RV show with no plans to purchase, and leave with an $80k fifth wheel.

Well, you apparently already had a truck capable of towing, so you were just asking for trouble! Haha. My little RAV4 isn't going to be towing anything anytime soon, so if I were to walk into a show and buy something, I'd have to push the darn thing home by hand!

[scottz]

Don't get hung up on the inverter style generator. That is not the inverter we are talking about. Regardless of the style generator, it still outputs AC. (I don't want to get into generator technology, that will just muddy the water)

The inverter we are talking about takes DC from your battery & solar (if equipped) system and converts it to AC. So, you can run your AC devices off your inverter as long as you batteries last. Then, you will have to crank up the generator to run your AC devices. Or, any combination of the two.

A "pure sine wave" inverter puts out cleaner AC than a standard inverter; at a substantially higher cost. Most things (not sure I ever found anything that would not) run fine on a standard inverter. The thinking is that computers and other sensitive devices prefer the "pure sine wave". (Once again, no need to go into the technology of pure sine wave vs switched sine wave) I have a 2000W pure sine wave inverter; not because I needed it, but I could afford it and that is what I bought.

You know those little inverters you see at auto parts stores that plug into your lighter socket so you can run a small AC device in your car? We are talking about the same thing, only bigger.

[EricHarmon]

Originally Posted by scottz

Don't get hung up on the inverter style generator. That is not the inverter we are talking about. Regardless of the style generator, it still outputs AC. (I don't want to get into generator technology, that will just muddy the water)

The inverter we are talking about takes DC from your battery & solar (if equipped) system and converts it to AC. So, you can run your AC devices off your inverter as long as you batteries last. Then, you will have to crank up the generator to run your AC devices. Or, any combination of the two.

A "pure sine wave" inverter puts out cleaner AC than a standard inverter; at a substantially higher cost. Most things (not sure I ever found anything that would not) run fine on a standard inverter. The thinking is that computers and other sensitive devices prefer the "pure sine wave". (Once again, no need to go into the technology of pure sine wave vs switched) I have a 2000W pure sine wave inverter; not because I needed it, but I could afford it and that is what I bought.

You know those little inverters you see at auto parts stores that plug into your lighter socket so you can run a small AC device in your car? We are talking about the same thing, only bigger.

OK, I think I've got it, thanks! I was a bit surprised by the price of the sine wave converter. I do use computer equipment (I'm a software developer and will be working a bit on the road), but I can certainly run the laptop off battery (or refrain from working!) for those days that we are on the Alaskan Highway and have to make due with no-electric accommodations.

[h2ojocky]

I have read on this forum that there are several out there that have the less expensive inverters and report that they work fine for everything in there trailer including computers. As far as the inverter generator goes, they basically are referring to the quiet generators that people use for camping, as opposed to a construction generator.

[Carl n Susan]

Typically the lower priced inverters are Modified Sine Wave (MSW) rather than the more expensive Pure Sine Wave (PSW) ones (although the prices are getting closer together.

The MSW models run most everything including laptop computers and any others which transform the incoming 120V AC to 12V (or 5V or 19V) DC. The two things which don't seem to react well to MSW are laser printers and things with 120V motors.

I have been running a cheap MSW for 10 years running TV, stereo, DirecTV box, power inserter, laptops and cell phone chargers. Never a problem. YMMV

[Mudchief]

Eric, the 6 volt batteries are lead acid or agm. You can get those at Sam's or Costco or any place they sell batteries. On our other Montana I had a 2000 watt inverter that cost around $400.00 and it would run everything except the Microwave. When we needed to run the microwave we just started the generator. On the Honda either one will work. The 2200 is just the new model of the 2000.

[jcurtis934]

And don't count on any model of fifth wheel still being available when you are ready to buy. If it is, the layout may have changed.

[artfuldodger]

I have a3000 watt Go Power inverter and it will power up the micro., but for battery reasons , not for too long and not on convection mode. The size of electric cable is very important between the batteries and between the battery and inverter. A good generator is a must because the sun isn't always out. I have a Honda 2000, but there are other good products on the market too.

[AZ Traveler]

Also have a GoPower 3000 watt inverter and a battery bank of 4 6 volt golf cart batteries. No issue running the microwave or coffeemaker for short periods. Recharge with shore power or Honda gennys. Solar going on in 2 weeks.