I love my RV solar system!

[NCmountainsOffgrid]

for some reality, as for the OP's 'question' about why so many other RVrs don't deploy 'solar', and use their generator, it really comes down to frequency of use: most RVs are used very infrequently. There's little need or desire for those owners to spend the type of money involved in making solar power any type of even long-term financial payback.
Also, most who 'camp' want to do that in the shade, since most 'camping' is during the hot summer months, so solar, again, is problematic, especially if you have 'roof mounted' solar arrays. Most who camp also don't buy a camper so that they can then go out and spend more on another type of 'power' system, when they already have 12v systems, 120v systems, and a generator, which they'd need anyway, even with any solar.
The camping world is also not a 'single track' mindset, when it comes to 'who' is doing the camping, what they are doing it 'for', and for how 'long' they are doing it - it's a recreational activity, not a business, and for the vast, vast majority, certainly NOT a full time home, where an investment in solar and other types of power sources might be more financially advantageous.
The RVing industry has certainly added their fair share of 'solar' products, pre-wiring options, and some newer high-end models that are 'all battery powered', as for the electrical systems, anyway - doing away with a generator in place of lithium battery packs, dual or triple inverters, and solar arrays on the roof... IF you have the money for that type of RV.

it's all good, no matter 'how' you do it! : )

[Wrybread]

Well again your opinion and not what others are thinking concerning solar to be easy and cheap.

My costs for the charging part of my system (the solar stuff) are about $530, and that's for 900 watts of solar power. That's a lot:

- $130 for a 300 watt panel (I have 3 of them, but 2 would do)

- $140 for a charge controller (link)

Without the 3rd mostly unnecessary solar panel it would cost $400, plus a bit for the wires. I call that cheap for limitless power that doesn't require any work and drastically extends the life of my batteries by keeping them charged, but as you say that's opinion.

As far as being easy, with the various solar forums on the internet, it's dead simple. There's lots of people who loving helping with this stuff.

I am glad your Trojan's are lasting a long time. Most people kill off their system quickly.

Honestly I'd be amazed if anyone's batteries could last 2 years without solar. Unless they're super diligent with charging, but then I couldn't imagine why someone would want to work so hard when there's such a simple alternative.

If someone needs batteries too, the simplest thing to do is add either 2 or 4 Trojan T105's ($135 each). Or I've had great luck with the Costco 6 volt cheapies (about $90 each), just make super sure to keep them topped up with water. Plus about $400 for a good inverter, the wires, fuses, etc. If money is tight you could easily get away with one or two 300-watt solar panels, that charge controller, the 600 watt version of that inverter (or just get a cheapie inverter), and 2 Trojan T-105's or the generic alternative. That would cost well under $600 for a solar system including batteries that would probably be far and away the best one in any RV park.



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[SunEagle]

I'm looking out at a sea of RV rooftops and don't see a single solar panel. I see lots and lots of room for them though! A real shame. And my camper is a 25 foot Class C, probably one of the smallest campers here, and I have 3 "house style" panels and could fit another. All it takes is a little ingenuity.



The cost of the gas is the least of it. The biggest factor I see is the hassle of having to do it every single day, and the damage you'll do to your batteries when you don't keep up with it. Why would someone choosethat over something that happens automatically? And of course there's the noise and the smell and the fact that if you don't keep on top of it you damage your batteries.



I know that's the prevailing wisdom on this forum, but 'm living proof that it's wrong. I deep discharge my batteries occasionally, and my 6 year old Trojan T-105's are going to last me at least another year, probably more. I don't know how much experience you have with Trojan T105's, but 6 years is really old for them. The fact that mine still work so well is proof that adequate and modern solar can charge a battery bank beautifully. I'd like to see someone keep their batteries this healthy after years of only relying on engine charging. Even if they're moving every day I'd say it would be impossible.

And besides it's not either/or, people can still of course start their engines in a pinch. But to rely on engine charging alone is a really silly idea idea in the modern solar era, with our access to dirt cheap high quality solar panels and MPPT charge controllers.

Well again your opinion and not what others are thinking concerning solar to be easy and cheap.

I am glad your Trojan's are lasting a long time. Most people kill off their system quickly.

But since I can't smell, running my engine is not an issue and the noise can be controlled. But in real life I choose to RV in campgrounds that provide power and water so I don't have to run my engine or worry about my batteries.

[Wrybread]

Sometimes there just isn't enough room on the roof of an RV to in stall solar panel to recharge the batteries properly

I'm looking out at a sea of RV rooftops and don't see a single solar panel. I see lots and lots of room for them though! A real shame. And my camper is a 25 foot Class C, probably one of the smallest campers here, and I have 3 "house style" panels and could fit another. All it takes is a little ingenuity.

Remember the cost of gas has been below $2 for a lot of states. So running the engine is not as expensive for some than for others.

The cost of the gas is the least of it. The biggest factor I see is the hassle of having to do it every single day, and the damage you'll do to your batteries when you don't keep up with it. Why would someone choosethat over something that happens automatically? And of course there's the noise and the smell and the fact that if you don't keep on top of it you damage your batteries.

Also solar may not provide enough charging amps for batteries that have been deeply discharged

I know that's the prevailing wisdom on this forum, but 'm living proof that it's wrong. I deep discharge my batteries occasionally, and my 6 year old Trojan T-105's are going to last me at least another year, probably more. I don't know how much experience you have with Trojan T105's, but 6 years is really old for them. The fact that mine still work so well is proof that adequate and modern solar can charge a battery bank beautifully. I'd like to see someone keep their batteries this healthy after years of only relying on engine charging. Even if they're moving every day I'd say it would be impossible.

And besides it's not either/or, people can still of course start their engines in a pinch. But to rely on engine charging alone is a really silly idea idea in the modern solar era, with our access to dirt cheap high quality solar panels and MPPT charge controllers.

[SunEagle]

I get that of course, but I don't get why that is. Now that solar is so cheap and easy, there's just no reason not to have all the wattage you need.

I think a lot of it is just misinformation. Saying that the motor charges "more effectively" for example is just factually wrong. There's not a chance my 4 Trojan T-105's would still be healthy after 6 years if I was relying on engine charging for example. They'd have dipped too low too many times years ago.

Sometimes there just isn't enough room on the roof of an RV to in stall solar panel to recharge the batteries properly. Again it is what someone wants to do and for most just running the engine is easier to charge the batteries then installing solar. Remember the cost of gas has been below $2 for a lot of states. So running the engine is not as expensive for some than for others.

Also solar may not provide enough charging amps for batteries that have been deeply discharged

[Wrybread]

Some people do not have enough solar wattage or charging amps to come even close to what an alternator can provide

I get that of course, but I don't get why that is. Now that solar is so cheap and easy, there's just no reason not to have all the wattage you need.

I think a lot of it is just misinformation. Saying that the motor charges "more effectively" for example is just factually wrong. There's not a chance my 4 Trojan T-105's would still be healthy after 6 years if I was relying on engine charging for example. They'd have dipped too low too many times years ago.

[J.P.M.]

I'll never understand that logic.
And the craziest part to me is that if someone is relying on their engine to charge up, they already have batteries, an inverter, etc. The solar panels are the cheap and easy part.

Comes down to you can't always get what you want.

[SunEagle]

I'll never understand that logic. My solar charges as fast as most alternators (I routinely hit 50 amps of output from my solar, measured at the battery), and I don't have to do a thing, it happens almost every day whether I'm using my camper or not. No noise, no fumes, no having to remember to drive around, no dead batteries because I forgot to do it. I don't have to use any gas, I don't have to stink out my neighbors because I'm running my vehicle without moving, no having to sit in the driver seat while it runs, no carbon monoxide, no fumes, no having to remember to stop the engine after awhile. I'm just always charged up, without having to do a thing.

But you think having to drive around or just run your engine every single day just to charge up is somehow preferable?

And the craziest part to me is that if someone is relying on their engine to charge up, they already have batteries, an inverter, etc. The solar panels are the cheap and easy part.

Some people do not have enough solar wattage or charging amps to come even close to what an alternator can provide. So it does make sense to run the engine and charge their batteries that way.

As for not wanting carbon monoxide, noise or fumes to be the result in battery charging, all I can say it that choice belongs to each individual to make,

[Wrybread]

How about if you start your engine, drive around a bit, and you can charge your batteries faster and more effectively?

I'll never understand that logic. My solar charges as fast as most alternators (I routinely hit 50 amps of output from my solar, measured at the battery), and I don't have to do a thing, it happens almost every day whether I'm using my camper or not. No noise, no fumes, no having to remember to drive around, no dead batteries because I forgot to do it. I don't have to use any gas, I don't have to stink out my neighbors because I'm running my vehicle without moving, no having to sit in the driver seat while it runs, no carbon monoxide, no fumes, no having to remember to stop the engine after awhile. I'm just always charged up, without having to do a thing.

But you think having to drive around or just run your engine every single day just to charge up is somehow preferable?

And the craziest part to me is that if someone is relying on their engine to charge up, they already have batteries, an inverter, etc. The solar panels are the cheap and easy part.

[GeorgeF]

How about if you start your engine, drive around a bit, and you can charge your batteries faster and more effectively?

[ewarnerusa]

Wrybread, I always enjoy your threads and posts about how well solar works for your RV. I usually comment that I love mine, too. So I'll do it again here. But mine is so small and simple that it isn't much of a comparison. I'm actually <300 watts on the roof with 12V panels and using a PWM controller as well! But the thing is, it is well matched for how we use the camper and I knew that when I built it. I built with expansion in mind with wiring and controller capacity (I thought I'd eventually double everything) but actually never have. We're fortunate to spend most all of our camping time in our homestate of Montana where air conditioning is not a requirement, but I do haul along a generator strictly for AC duty these days.

Some specs
2x 140 watt Cynergy 12V panels wired parallel to junction box on roof. 4 gauge wiring from junction box to charge controller
Morningstar TS45 PWM controller. 4 gauge wiring from controller to batteries
2x Costco GC 6V batteries
300 and 1500 watt PSW inverters, wired with 2 gauge wiring to batteries
All camper lighting is LED.

[Wrybread]

I get that, but a 12 volt battery bank made of four 6-volt batteries is already two 12 volt banks in series (2S2P). So what's different if someone wired those 4 6-volt batteries as 2S2P and took their 12 volt connection from that (as I'm currently doing), and additionally added 4S connections for their 24 volt inverter? Probably should be a separate thread, but was wondering. I'm guessing they'd still discharge unevenly, but as you say that's inevitable in all configurations as far as I know. And maybe it's overcome by the charge controller's equalization cycle.

(And to be clear, I don't know about the above, just wondering).

[bcroe]

Out of curiosity, what would damage them? If you parallel the two 12 volt battery banks in a 24 volt system made of 6 volt batteries, the batteries should (I think, I've never done it, and not recommending it, just wondering) be discharging at the same rate. So what exactly damages them in that configuration?

If you connect a load from one end to the center tap, you are only discharging half
the batteries. Eventually one half will be charged when the other half is partly
charged, which can damage half and eventually both halves.

Connecting batteries in parallel will never discharge them exactly evenly, since
nothing under the sun is perfect. Eventually the same problem happens, and
as they get more unequal the life is shortened.

What you can do is momentarily connect banks in parallel for a short heavy
load, such as starting an engine. But after that the banks need to be separated
and individually charged up.

The battery experts may say more. Bruce Roe

[Wrybread]

the 18 VOtls from the panel directly to it.

Have you measured that voltage with a load attached to it? It's probably pretty close to 12 volts...

[Wrybread]

Yes people talk about tapping into a lower voltage on the battery string, a good
way to damage them

Out of curiosity, what would damage them? If you parallel the two 12 volt battery banks in a 24 volt system made of 6 volt batteries, the batteries should (I think, I've never done it, and not recommending it, just wondering) be discharging at the same rate. So what exactly damages them in that configuration?