We are electric everything (fridge, freezer, bread maker, electric jug, electric blankets, lights, couple of computers, cameras, central heating fans, bed fans, ........) except hot water (diesel) and cooking (gas).
We have 600W of solar, all fixed and that is plenty 99.8% of the time. For that 0.2% we can charge from the alternator. We have no generator and no 240V input capability.
The more you travel, the more you will want "set and forget".

Cheers,
Peter

Passingthru wrote:

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Hi, Just wondering the about the Pros and Cons of having Solar Panels mounted on an RV - VS - Not Mounted?  Perhaps some of you have both?  I'm looking at buying a Toyota Coaster in the near future.  

I'm thinking for more long term RVing ... Not weekend getaways.

Thinking with Off Grid 'Full Time RV Living' in mind and digitally dependent with photography and video rendering off a high end gaming laptop, I'm currently thinking in terms of 600W minimum Solar panel capacity.  I'm unsure as still learning and no experience.  I'm amusing with those kind of expectations I will be hard pressed as is counting everything else that I'll need to run fans, lights, small fridge and so on.  At any rate ... the capacity of system is not decided other than it will need to be larger than your average weekender.  So just keep that in mind with regards to formulating a response.  I really don't want to use a generator except in extreme conditions for AC which I am intending to avoid.  Yet something else I have no idea about.  

Forgive my ignorance.  We all have to start some place.
_________________________________________________________

So how much of an annoyance is it having to rely solely on parking in the sun with regards to 'solar only' setups?  

What is the the appropriate distance from RV with an unmounted solar setup could one expected to run without too much loss or disruption to self and others?  I'm thinking in terms of efficiency loss, hindrance and safety in various circumstances?  Anyone with experience in this kind of setup?  Would love to hear your thoughts.

I'm thinking of having both Vehicle mounted and unmounted, yet wondering if Panels on the roof will only add more heat to RV?   

Additional thoughts for now:
Having Air Con roof mount Vs rear mounted?   Roof Mounted AC with additional roof mounted Fan Vents would mean little space for roof mounted solar panels?  Fans Vents being more solar friendly?  

How beneficial is it having a dedicated fan setup with ventilation in mind - for Full Time Rving off grid in the Summer months Nth QLD.

TY

 

 

-- Edited by Passingthru on Monday 4th of December 2017 06:57:44 PM

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Welcome to the forum, Passingthru

Pro and Cons as I see it, which may be different than others see it

Panel on the roof

Pro, fit it and forget it
Con, If you wish to park under the shade of a tree (to cool the vehicle), the solar will not be much good

Portable panel carried inside the vehicle

Pro, you can park in the shade, and place the solar panel in the sun
Angling the panel to the sun, will give more amps/watts than having it flat on the roof
Con, It takes up space inside the vehicle
You have to set it up, at each camp you stop at, then move it with the sun to get the best benefit

The appropriate maximum distance from the vehicle for a portable solar panel, is the length of the cable which is attached to it
As an explanation of the above, a portable solar panel usually comes with the regulator, and cable already attached

A roof air conditioner could be putting some shade over the roof solar panels  
A rear mounted air conditioner should work just as good as a roof mounted one, as long as it is up high
Cold air will eventually go lower than warm air

Concerning the fans, I am unable to answer as at the moment I do not have any fans hard wired, but I do carry 12 volt fan

For the record, I have 1 x 300 watt solar panel on the roof, going through a 20 amp DC/DC regulator, set up at the 2 x 120 AH AGM batteries
I have a roof mounted air conditioner, with the solar panel, fitted between the air conditioner and the end of the vehicle
With the rear of the vehicle facing a northerly direction, the air conditioner does not shade the solar panel

I will shortly be fitting a 12 volt upright 110 litre fridge, in lieu of the three way fridge I have recently removed,
I shall find out on my next trip, (within the month), if I need more solar/battery/regulator

Hope that this info is useful to you, but remember that it is only my opinion, from experience of my situation

Thanks guys. I certainly have a lot to think about. My RV solar proposal being a one off purchase (for many years at least) means I won't have the advantage of hindsight with regards to first time jitters, but I do heed the weight and storage concerns re an unmounted system. That said I am tending to have both a roof mounted and unmounted system. I've opted out of using my high powered laptop. I have another laptop that uses half the power still capable of rendering video that could be restricted to processing @ daylight hours. That would mean I could at least half the size of an unmounted system which would make for easier storage plus easier setting up and breaking down.

I'm thinking 12V fans for an intake and outtake - need to research more on that. Those fan recommendations that you make meetoo look good. Perhaps a little pricey but I would not know as of yet. Having 'quiet' fans would be a bonus! Main reason I do not want to use a generator is due to my sensitivity to noise Fullstop. However - fan noise might come in handy if and when I find myself surrounded by others. : ) Then of course quality products tend to cost less in the long run.

I'm excited ... no doubt about it. I just don't want to get caught out with not having enough power and also would like to not drain my batteries past 50%. I can't underestimate that my first time setup is going to be it for many years to come. In the beginning we wont be full time RVers, but we are planning on it soon enough. I guess reading my books off a kindle, surfing the net on a tablet and using USB chargeable devices in general would be a wise decision with respect to digitally minimizing. I would imagine there are some backpacking lithium battery solar systems that could help carry such a load without too much fuss?

Not sure about the detriment of charging of the vehicles alternator with high charge rates? The mounted system I really want to nurture with respect to doing all I can to preserve it's life. Seems I have a lot to read up on. I thought one could drain batteries to 40% and then even hearing others say all the way down to 30%. I have started reading and see there there is a lot of misinformation out there and no offence, the reported claims point towards the marketing and sale outlets misguiding purchasers. I remember reading up on solar as some 30 years ago at age 18. You would think we would have come further with regards to simplifying the process. I think in some ways it's been further complicated.

From what I am reading ... it's not worth going a 24 or higher voltage system in an RV. Other then my laptop ... I assume it's best just to focus on DC?

Hope you don't mind the ongoing questions.

Really appreciate the feed back and advice.

TY.

Hi,

Look at semi-flexible panels to make up portable panels - more expensive but a lot less weight.

David

Real life experiences. We have a Mazda 3500, sort of a mid wheel base Coaster size, all electric including cooking on an induction cooktop, 12v compressor fridge, 3,000/9000w inverter for heavy use 240vac appliances and 400w PSW inverter for the electric blanket and charging the myriad of things that seem to be battery powered these day. The fan is a Fantastic Vent unit that has a cover that lifts, the fan runs in both directions and can either be auto temp controlled or speed controlled over a large range of speeds. we added a Maxxair hatch cover over it so it can be left open in the rain. We mounted at the rear of the roof that is roughly over the middle of the bed, cool air blowing in at night makes sleeping in the warmest conditions quite comfortable.
We have 360Ah of lithium battery that are now over 5yrs old and 700w of solar. We have run it down so far we couldn't start the engine on one occasion (no start battery only house battery) so it was well below the point the Victron 700 BMV said 0% SOC, but the sun finally came out and the battery recharged enough to start the engine and the alternator combined with the solar had it back to 100% by the end of the day.... well by the time we reached where we were going it was 100% so no idea just when it got there. We have had it below 20% many times (this is when the Victron 700BMV alarm is set to go off) and as yet we have seen no reduction in either the capabilities or the capacity.
Initially we dragged 400w of portable panels (2 x 50w panels x 4 sets) but tired of that real quick, we only use the roof top solar and alternator now. Just like Peter, we don't have anywhere wired up to plug an 240v lead into, just haven't needed it so haven't ever gotten around to wiring it up again, so it just fills in a hole.

We have recently taken over the ownership of a Hino 145A, full 24v, a rooftop fan and vent cover the same as in the Mazda, split system 240vac air con, 240vac fridge, 240vac hot water and 3,000w inverter that runs 24/7. It has 180Ah @ 24v of lithium batteries that are now about 4yrs old and 720w of cheap Chinese solar on the roof. For the 3 weeks we were away doing an install we lived in the Hino, hot as hell in Crystal Brook SA so the air con got thrashed day & night. We did end up needing to plug in for 8 hrs after 3 days of overcast/rain and the coffee machine, jug, induction cook top, air con as well the fridge etc dragged the battery down to 5%. we weren't going anywhere so we couldn't really justify starting the engine to recharge the battery when there was an extension cord right there for us to use.

If you want to add portables, go with the suggestion regarding the light weight portable panels, or like a mate did, fold down panels that act as window shades that he swings out when parked up, even easier then :lol:

T1 Terry

Hi Passingthru.

I have a Hino rb145 which is 7mt long the same as the Coaster. Up top 4 x 200w x 24v panels run as two separate pair, two at the front and two towards the rear. This helps with shading as the sun moves. Plenty of panels also keep the sun off the roof which in turn helps with keeping the bus a little cooler. It's not a good idea to park under gum trees anytime especially in summer. I have also fitted LED lights throughout which also helps with keeping energy use down. The bus is run as 24v with a small 24v to 12v reducer for radio's etc. Fridge is 175 lt 12/24v and is never turned off. Batteries 190 ah @ 24v always fully charged well before lunch in Melbourne winter. A good idea to paint your roof with a couple of coats with Thermalite added. This can be done easily with a roller.

Good luck with your decision making.
Cheers Rob.

Again ... excellent information. Interesting point re tree branches. :) Much appreciated. Can't say about the coaster yet but get your point ... its all on the drawing board. Not sure about the alternator being the best charger - given the rate of charge? Is there a way to ensure slow charging rates from an alternator. Money is of concern to me so as good as the flexi panels sound ... I really like your point about using smaller panels for carting around. I have no doubts that everyone's points are valid and in the end the best way for me to work it all out is going to be from experience. That said the info given is this thread is already helping to alleviate concerns, although raising more question. :)

"A good idea to paint your roof with a couple of coats with Thermalite added. This can be done easily with a roller."  Nice Tip!  I like the sound of that.  I have some time to pass so going to research that now.

Hi again,

Before deciding on smaller portable conventional panels it is still worth checking out the huge weight difference of flexible panels - more expensive but can go a lot larger & still far less weight - check out on Ebay for weight to power & price  comparisons.

David 

Peter_n_Margaret wrote:

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Not sure about the alternator being the best charger - given the rate of charge? Is there a way to ensure slow charging rates from an alternator.

You should have no concerns about this.

Battery charge rates are determined by 3 factors.... 1. The voltage of the source......2. The rate of acceptance of the battery......3. The power available from the source.

Whilst the alternator provides a lot of potential power, at around 14.3 the voltage is relatively low and the battery acceptance rate (its chemistry) will control the actual charge rate. If you boost the voltage, the charge rate will increase significantly.

That is why your crank battery does not get overcharged by the alternator. Nor will your house batteries.

Cheers, Peter

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 Hi Passingthru

I agree totally with Peter about this. I have used it for years in two MH at 24V and 12V, works quite well and no problems. If you use AGM house batteries they charge easily and accept good rates of charge quite well. If your book says otherwise I would doubt its value

Al Toyota Coaster LWB busses have a six cyl diesel and use 24V system AFAIK. The SWB busses are older than <1990s,  and may be 12V petrol or 24V possibly if diesel depending on various factors. The old busses are dissolving as we speak.

Jaahn

Sounds like an awesome setup Aus Kiwi. 

Smiles re my apparent hang ups. Thanks for the analysis. I understand well enough the process on that score.  Despite my mention of it, I'm not wishing to calculate my power consumption at this stage. I like the idea of working towards using less whilst starting with as many panels as I can fit ... either on or off my intended vehicle.  What can I say ... I like to work backwards and then adjust in my own way.  Thx all the same John. 

Yep - if little bus runs on a 24V battery - I will still be using a 12 volt system.  (I'll work something out) I have my reasons. In fact I kind of see things a lot different from what I have been reading in general. But that's OK ... we need not all agree. It's good to be different. I'm just gleaning and working with what rings for me. In fact it's plain to see from many of the responses not everyone is the same ... nor agrees.  It really is a personal thing and what clearly works for one may not be appropriate for anothers means. 

I took your suggestion David and after some looking I came across the following. I am very interested in the 250W version using it by itself or with the option to hook up to RV: Even if I just run my Laptop off it!!!  lol Just kidding. :P 

KICKASS ULTRALIGHT 250W 12V Portable Folding Solar Panel

 

 

 

 

-- Edited by Passingthru on Thursday 7th of December 2017 02:04:16 PM

Speaking of Terry do you have any dc/dc chargers there I think mine might be kaput . I recon it could have a loose wire cause if ya punch it sometimes it works . And della is getting sick of traveling in the van boot to keep it running . I will rip it out wile there and if its not fixable I will install a new one

Dibs

Passingthru wrote:

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snip

Smiles re my apparent hang ups. Thanks for the analysis. I understand well enough the process on that score.  Despite my mention of it, I'm not wishing to calculate my power consumption at this stage. I like the idea of working towards using less whilst starting with as many panels as I can fit ... either on or off my intended vehicle.  What can I say ... I like to work backwards and then adjust in my own way.  Thx all the same John. 

Yep - if little bus runs on a 24V battery - I will still be using a 12 volt system.  (I'll work something out) I have my reasons. In fact I kind of see things a lot different from what I have been reading in general. But that's OK ... we need not all agree. It's good to be different. I'm just gleaning and working with what rings for me. In fact it's plain to see from many of the responses not everyone is the same ... nor agrees.  It really is a personal thing and what clearly works for one may not be appropriate for anothers means. 


-- Edited by Passingthru on Thursday 7th of December 2017 02:04:16 PM

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 No problem Passingthru. Just trying to be of help, seeing as you asked the question.

Regardless, the power required to run what you want to run is non negotiable, no matter if not everyone is the same.

Anyways, setting up a van or coaster etc for the first time is a daunting job. Just work through it and you will eventually get it done. I thought I had got it finished years ago hmm, still working on it 20 years down the track, always something more to do - the nature of the beast.

Cheers, John.

 

Hi John.

I totally agree with your comments re. moving and pegging portable solar panels John.
I started off doing that when using the camper trailer and became so fed up with it I extended the roof rack on the patrol to the bull bar and placed them up there.
I now have the perfect sunvisor and the panels can be removed if need to remove them.

daffyfrancis wrote:

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Hi,

I would think that most would realise that the idea of portable panels is to enable better positioning throughout the day & to enable parking the RV in the shade - I presume if moving it several times a day is a problem it would be still more efficient left in 1 chosen spot away from the shaded RV than having the same panel on the shaded RV.

The biggest problem with expensive or cheap portables may be their security when & if you are away from the set up.

David

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 You are absolutely right daffyfrancis, with normal portable panels. The panels the op is talking about, are very lightweight, don't have a solid aluminum frame and have a strap and peg system to hold them upright, also helping them not to blow over too. Lots of extra work with them over and above regular framed portable panels. And at the price of $1297.00 plus shipping costs, one might like to know any setbacks before rather than after purchase. Plenty other options available to the op as well.

Cheers, John.