Parksy
Moderator
Hi Anseo
With a bit of research you should be able to obtain the components for a good solar set up for around £200.
A typical 150 watt 12 volt solar panel with mounting brackets which bond to the caravan roof is around £120
[*]you'd need a MPPT solar regulator to avoid frying your leisure battery, around £35 should do it
[*]A waterproof cable entry shrouded gland will get your cables from the outside to the inside
We're up to around £165 worth of haggis bonds now, but you also need suitable automotive flex and the bonding agent to roof mount your solar panel and entry gland, so around £200 or slightly over should get you there for a good solar set up that will do the job for you.
You might find less expensive components, I just had a very quick look and it pays to shop around.
I'm sure that forum members will be happy to offer advice on how to assemble and fit your solar set up, Click Here to see how I did mine.
With a bit of research you should be able to obtain the components for a good solar set up for around £200.
A typical 150 watt 12 volt solar panel with mounting brackets which bond to the caravan roof is around £120
[*]you'd need a MPPT solar regulator to avoid frying your leisure battery, around £35 should do it
[*]A waterproof cable entry shrouded gland will get your cables from the outside to the inside
We're up to around £165 worth of haggis bonds now, but you also need suitable automotive flex and the bonding agent to roof mount your solar panel and entry gland, so around £200 or slightly over should get you there for a good solar set up that will do the job for you.
You might find less expensive components, I just had a very quick look and it pays to shop around.
I'm sure that forum members will be happy to offer advice on how to assemble and fit your solar set up, Click Here to see how I did mine.
There's plenty of choice on ebay - you should find a 100w kit for well under £200.
The kit you were looking at only had corner support brackets. Personally, I would select a kit that has 2 side supports as well i,e 6 in all , to stop the panel flexing in the centre, and provide more bonding area. A good kit will come with correct solar wiring as opposed to automotive wire, and proper solar connectors, not croc clips
The kit you were looking at only had corner support brackets. Personally, I would select a kit that has 2 side supports as well i,e 6 in all , to stop the panel flexing in the centre, and provide more bonding area. A good kit will come with correct solar wiring as opposed to automotive wire, and proper solar connectors, not croc clips
Parksy
Moderator
The random example that I demonstrated isn't a kit and while I agree that the solar panel will have pre - fitted tails the automotive flex is the correct material to use to hard wire the system to the caravan as I did.I didn't use crocodile clips, the regulator is connected to the charging circuit using a plug in from Sargent. Solar panel mounting brackets of various kinds can be bought separately.chrisn7 said:
Sorry Parksy but I will disagree with you on the wiring. A roof mounted panel may need a longish wiring run, and correct solar cable has far more fine copper wire conductors than automotive cable, to minimise voltage drop. This cable is the same as the tails that come pre fitted to the solar panel. You only have to look at the bared cable to see the obvious difference.
Of course the correct cable connectors should be used too for similar reasons - they have be soldered to the cable, are water proof and polarity protected. Forget any automotive plugs, cables, connectors for minimal resistance and reliability in the system
Of course the correct cable connectors should be used too for similar reasons - they have be soldered to the cable, are water proof and polarity protected. Forget any automotive plugs, cables, connectors for minimal resistance and reliability in the system
chrisn7 said:
Are you saying there are more conductors, but finer, so the total cross-sectional area could well be the same as automotive cable. If so then the voltage drop will be the same if the copper material is the same. The only difference will be that the overall cable will be more flexible. The same reason that caravans have flex cable rather than solid for its 230v wiring.
Parksy
Moderator
chrisn7 said:
I think that we'll have to agree to disagree on this issue Chris.
I conducted the research which indicated that no matter what cable is used voltage drop will occur, but the difference between the correct true 6mm automotive flex cable (the insulation isn't included in the cross section) and 'solar cable' (which is exactly the same only tinned) is negligible in terms of voltage drop (if any) but with a 100% difference in price for the same cross section.
Please be assured that having conducted the research before I did the work, the interior connections that I made are fit for purpose, secure, soldered and fully waterproof. The panel connections on the roof are from solar cable fitted to the panel through solar couplings to extend through the cable entry gland and shroud.
The plug supplied by Sargent is the correct part for my particular caravan, it plugs directly into the caravan charging circuit via a female connector fitted during the manufacture of the caravan by Swift. for that specific purpose.
It's all a matter of individual choice, but my system isn't some kind of cheapo bodge job, I read up all of the information I could find at the time and used components widely recommended and reviewed.
There is quite a lot of mis-information in general about caravan solar installation and from what I've seen for myself a significant amount of it is designed to part an enthusiastic fool from his money, and ''kits'' with the word 'caravan' associated with them always attract premiums for no good reason.
My individually sourced solar system has worked fine for the past three years using the components described in the fitting instructions from my earlier link.
Parksy
Moderator
I forgot to mention that all of the panels that I've seen are protected against reverse polarity.
All electrical conductors (Even super cooled super conductors) offer some resistance to the flow of electrical current. The value of a resistance (R) is measured in Ohms, and the more Ohms the greater the resistance it offers to the flow of current. The converse of resistance is Conductance and is described as Siemens (S) S = 1/R
At low voltages (i.e. less than 1500v dc or 1000vac) the current flowing an a copper conductor can be considered to have equal current density across it's cross sectional area. In other words; there is no surface charge effect that arrises with electrostatic voltages. Given that, the current handling capacity of a conductor can be considered to be directly related to the total Cross Sectional Area (CSA) of the conductor. It does not matter if its a single core conductor or mutli-strand conductor.
At low voltages (i.e. less than 1500v dc or 1000vac) the current flowing an a copper conductor can be considered to have equal current density across it's cross sectional area. In other words; there is no surface charge effect that arrises with electrostatic voltages. Given that, the current handling capacity of a conductor can be considered to be directly related to the total Cross Sectional Area (CSA) of the conductor. It does not matter if its a single core conductor or mutli-strand conductor.
ProfJohnL said:Hello Anseo,
I suspect you may be over complicating the answer to your problem. Referring back to my quick calculation, I suspect you will more than enough capacity with a the 150W panel a simple controller, and a 110Ah battery.
A second battery is a another possibility, but then how do you charge it, and as has already been mentioned it adds weight and it must be secured and stowed properly in an acid proof container ventilated to the outside. It may seem a lot of work and expense for little reward.
Whats the worst that could happen? :huh: (perhaps i'm opening an can of worms herehmy: but) you may have to curtail the television hours a bit. :blink: You may have to relearn the art of conversation over some liquid refreshment!" :cheer: Or discover the delights of arguing if "ix" is a allowed in Scrabble. :evil:
I like your quips there Prof! Wish I'd seen all this before I posted my question earlier. Don't know how I missed it? I have found a supplier here local that has both 90 watt and 60 watt folding options that will suit me. I plan to bond plastic corners on plastic squares onto the roof just behind my roof light.Not being regular off grid caravaners, I'll just place it there when camped and drop the leads to the battery.
Not sure how old this is but we like to watch
Quite abit of tv and do mostly rally's I just got another 110 battery and run the TV just from that (cello 16w) can get 4 nights easily and because I have a battery just for the TVs will never run the main battery down, I have changed all lights to led, changing the van Next month and I'm told the new heating has no convection fire just blow heating so not sure how the main battery will get on then ?????? I'm getting a xplore 554
Quite abit of tv and do mostly rally's I just got another 110 battery and run the TV just from that (cello 16w) can get 4 nights easily and because I have a battery just for the TVs will never run the main battery down, I have changed all lights to led, changing the van Next month and I'm told the new heating has no convection fire just blow heating so not sure how the main battery will get on then ?????? I'm getting a xplore 554
Peter_374304682 said:
Me too, I wonder what the draw on the battery will be using the blown air system.
I can't answer the question of how much current the heating will take, but I suspect the manufacturers are expecting most caravanners to be using sites with mains hook ups.
Looks I will be getting an100w portable panel to keep the battery topped up, if I have to start going on commercial sites the van will be up for sale and back to premier inns god i sound like a right miserable git
ProfJohnL said:
Guess I will need to get out there and find out Prof, I have a spare battery for back up so not too concerned about battery depletion.
And I will get round to purchasing the solar panel (I'm having second thoughts and considering a portable folding panel now :blink: ).
Anyone used gas and the blown air system off grid ? Even a rough estimate of current consumption would be helpful.
Anseo said:
The blown air system when on full blow will consume no more than 1.5A an often less when its turned down
ProfJohnL said:
Prof, can you help me a little bit more please ?
Is that 1.5A per hour, or what ?
Thanks,
Anseo
Anseo said:
Hi
Ok in simple terms a current of 1.5A (Amps) if running continuously will deplete a battery by 1.5Ah each hour.
Current x time = "Ah's" which is how the capacity of a battery is indicated
But as I suggested that is its peak current consumption when turned on fully, In most cases once the caravan is warmed up the fan speed can be dropped and that will reduce its current consumption quite significantly.
If you halve the rotational speed of the fan, it will reduce its current consumption to about 25% of the previous speed, so at half speed it will draw something like 0.375A (or 375mA) and if you take it down to 1/4 speed it will only consume about 0.1A or (100mA) This in not perfect description as there are other factors involved but generally the lower the fan speed the less power it will use from the battery.
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