No. of Solar Panels.

[Craig]

Have been away and recently revisited this thread. Having 7 panels on a 7Mr bus including a 4 seasons vent and the 2 big roof fans was a job. The result is still the same as before. The panels charge the LIPO battery pack. It feeds the inverter. It powers the F&P fridge. It also powers the satellite TV etc. The battery also feeds the led lights, the pump, the deisel heater and anything else I can think of. So far, even with crappy weather, on a good day, by 11am I am feeding the excess solar into the 240V hot water element. On a gloomy day, we use the gas for the hot water, the solar is busy with the fridge etc.
Still smiling, best investment ever made.

You can't have been away for too long, you made a similar comment yesterday.

[shonky]

Hi, all.

T I Terry - the fridge is a 6 year old Dometic 90ltr 12v compressor unit, and to date the light cable running over the roof has been replaced with heavier cabling direct to the batteries, a large intake vent installed and the exhaust fan replaced. Left alone it draws between 3.5 and 4amps and cycles on/off "reasonably often." We do turn it down as much as poss at night.

Did you receive my PM?

[T1 Terry]

Got your PM, do you have a fan inside the fridge as well, blowing air down from the top shelf across the evaporator plate? This reduces the ice layer build up and steadies down the cycling rate as the fridge temp evens out better. a second fan blowing air across the compressor housing seems to work well too, does the fridge have an air gap underneith to let the air enter and circulate? Just seems a lot of Ah over night for such a small fridge.

[Craig]

Maybe it is low on refrigerant gas. It will short cycle if this is the case.

[John M]

Maybe it is low on refrigerant gas. It will short cycle if this is the case.

I do not know with the Dometic, but my Waeco will short cycle on low voltage, when the compressor starts up it will drop the volts to below the cut out point, and the fridge will cut out, as soon as the compressor turns off the volts raise to above the critical point and the fridge starts again, dropping the voltage and so on ad finitum, until the fridge is turned off or the batteries are charged!

Shonky, one thing that may be worth checking is the diodes on the solar panels, they are situated in the connection box on the back of the panel, on a number of the better branded panels they use two diodes connected to a central connection, one of my older 80w panels had blown diodes, they are easy to identify if they are blown (or have a broken leg) they are cheap enough just take one of the old ones to Jaycar they will sell you a pack of ten (minimum quality) for a couple of dollars, (cant remember the exact price but less than a dollar each) same for fuses, from Jaycar, buy the 5AG 30A fuses under $2.00 each, and the fuse holder to suit, for under $10.00, the same fuse holder from Su######eap are $19.95 ea.

[shonky]

Hi, all.

Guys, my concern is not so much with the fridge - we're now keeping it at a temperature slightly above freezing and it's drawing just over 2amps. Three will just suffice and reading other forums this amp draw is fairly standard even with new Waeco 12v compressor fridges.
My frustration is with the low performance of the panels mid-year. They were all checked out by a local auto-leckie and pronounced satisfactory.
In hindsight one should have at least a third of his solar panels as folders for use from May to August. It crossed my mind to affix a 140w panel vertically on the back of the vehicle for this time-frame and only park facing South. Accordingly the new 140w folder will be hanging out the back window while we're at Maroochydore for the school holidays. You will recall that a 140w fixed panel gave out 8amps at 9am last month at Apple Tree Creek when resting it against the "bumber" - not my word but apparently RV jargon. I noted that there were many gensets running at the time so the problem appears to be a common one. Incidentally we were quoted $650 to install a 140w panel on the roof or $550 for 120w. 600mm of alloy angle chopped up, sikaflex, cable, screws etc. and use of a battery drill.
Quick question - if fitting a third AGM battery, allowing for the length and diameter of the cables, should it be the same amperage as the existing pair?

Incidentally, straying off the subject, Apple Tree Creek has it's own piecart and the Apple Crumble with custard - available after 0915 - is delicious. The "20" sign means the number of days you can stay there and for longer stays one moves to the paddock down the end. The council apparently believe that free camping means income for the town. Oh, yes, for horse lovers one can see the dressage ponies being worked out nearly every morning.

[shonky]

Hi, all.

Almost forgot - there's an article in an English forum about a folder resting vertically against the bumber of his RV with a mirror of the same size laid horizontally in front of it. And it works.

[T1 Terry]

Using that idea, with sun end at the forward panels, a piece of polished stainless angled over the rear panel should improve the solar collection during the winter mths. maybe it could fold back and slide under the rear panel. An easier idea is this one,

Solar panel mounting.JPG

Leg stored for travel.JPG

the idea is, the solar panels are mounted on 150mm x 50mm aluminium angle with the lip over the top of the panel. a second piece of aluminium angle, tall enough to hold the panels off the roof all the way across, is sikaflexed to the roof by the narrow side. Both pieces are 50mm longer than the panels, bolts positioned 10mm in from the ends and rivet nuts in the aluminium angle the panels are mounted to, corresponding holes in the angle fixed to the roof. The leg bolts on the outside 3 securing bolts for travel and bolts between the bolt hole on the roof aluminium angle and the rivet nut on the solar panel aluminium angle, the further along the panel, the greater the angle. Works well for cleaning and wiring maintenance as well.

[Craig]

Hi, all.

Guys, my concern is not so much with the fridge - we're now keeping it at a temperature slightly above freezing and it's drawing just over 2amps. Three will just suffice and reading other forums this amp draw is fairly standard even with new Waeco 12v compressor fridges.
My frustration is with the low performance of the panels mid-year. They were all checked out by a local auto-leckie and pronounced satisfactory.
In hindsight one should have at least a third of his solar panels as folders for use from May to August. It crossed my mind to affix a 140w panel vertically on the back of the vehicle for this time-frame and only park facing South. Accordingly the new 140w folder will be hanging out the back window while we're at Maroochydore for the school holidays. You will recall that a 140w fixed panel gave out 8amps at 9am last month at Apple Tree Creek when resting it against the "bumber" - not my word but apparently RV jargon. I noted that there were many gensets running at the time so the problem appears to be a common one. Incidentally we were quoted $650 to install a 140w panel on the roof or $550 for 120w. 600mm of alloy angle chopped up, sikaflex, cable, screws etc. and use of a battery drill.
Quick question - if fitting a third AGM battery, allowing for the length and diameter of the cables, should it be the same amperage as the existing pair?

Incidentally, straying off the subject, Apple Tree Creek has it's own piecart and the Apple Crumble with custard - available after 0915 - is delicious. The "20" sign means the number of days you can stay there and for longer stays one moves to the paddock down the end. The council apparently believe that free camping means income for the town. Oh, yes, for horse lovers one can see the dressage ponies being worked out nearly every morning.

Or maybe I made a typo. good luck with your set up

[shonky]

Hi, all.

This pretty well sums it up.
http://www.candm.com.au/forum/viewtopic.php?f=6&t=15552

Note one of the contributors has a folder, probably resting it on his bumber. Sorry, couldn't resist it.