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Ean Austral
26th August 2009, 09:40 PM
Gday All,
I see a few threads on solar panels and 80w seems to be the general view but wondering how you have these set up..As a battery charging system for the duel battery....Or somehow run fridge etc straight off the panels.
80w seems alot to use as just a charger..Excuse my ignorence but never used a solar panel set-up before..
Thanks and Cheers Ean

Ean Austral
26th August 2009, 10:17 PM
Its OK I had a brain lapse,the watts convert to amps of charge...Should make sure the brain is working next time.
Cheers Ean

land864
26th August 2009, 10:51 PM
Hi Ean

I've just done a fair bit of research on the same topic.

80 Watts is recommended by all those in the know.

I just bought an 80 watt set up.

I am told that the idea is;

If you're going to prop for a while and not run your vehicle for a few days then , fit the solar panel to the vehicle battery ( that is your deep cycle second battery if you have one or just the single battery ) as soon as you can , in full sun.

This should ensure that your battery is always being topped up with more amps than what your 12 v camp lights and vehicle internal lights and fridge can draw.

It can be too late when they are already flat.

Given time they will come up in charge again but best to avoid that if possible.

Do the old electrical equation ( volts x watts = amps? )for all your lights and fridge and stuff ( fridge may already list amps drawn) and work out how many amps you will draw for the time you are stationary.
See how many amps you will use per hour for that period and deduct that form how many amp hours your battery is rated for. ( I think that's right:confused:)

Some tips for the fridge are ; keep it out of the sun if possible, buy a cover , set it on 6 degrees and not 4 to reduce run time , as you empty the fridge fill the empty space with crumpled up newspaper ( open vacant air space is more difficult to cool than the little voids made by crumpled up newspaper.

Some people run their fridge as a freezer only. When everything is frozen the thermal inertia made by the frozen stuff assists in keeping it cold.
(You freeze it at home on 240v power)

They tell me the secret to this , is to have a seperate smallish esky and two good size freezer bricks.

Open your fridge/freezer once a day in the morning to get frozen food out.

Use that and one freezer brick to keep the drinks cold.

Swap the freezer bricks as necessary.

Sorry , that turned into the Second Epistle of Paul , regarding Fridges :)

Pete

Ean Austral
27th August 2009, 12:48 AM
Thanks Pete,Did you come across anyone that stood out for price etc when you purchased yours or were they all much 4 muchness..Not to sure on how much competition there would be in Darwin so may have to source from else where.
Thanks again, Cheers Ean

land864
27th August 2009, 01:34 PM
Ean

Only buy monochrystalline panels.

Do a google on mochrystalline versus polychrystalline versus amourphous

Fleabay units sell for around $550 with controller , leads etc. Not sure what % efficiency they are. That is important.

I managed to get an ex demo set of e solar panels c/w controller , carry bag , leads etc for $ 350 but that was a bargain.

I'm told they normally retail for $ 1100.

When I started out looking , someone told me a rough rule is $ 10/watt therefore 80 watts x $ 10 = $ 800 plus controller and leads and carry bag if needed.

Good luck

pete

numpty
27th August 2009, 05:42 PM
I'm no expert either, but do concur with most of the previous post. I intend sooner rather than later to go solar, but remember you will normally only get 5 to 6 hours a day of full output from the panel.

handy
29th August 2009, 06:56 PM
I've used solar panels on a 3 vehicles in the past. I always use Uni-Solar 64 Watt panels. They are shade tolerant & supposedly bullet proof, which basically means it is going to have to be very nasty hail to do damage to the thing. The Uni-Solar 64 Watt panels are larger than other's of the same rating, but according to the experts (sorry no links) they are equivalent to an 80 Watt panel due to their high efficiency. Unlike other panels, as the temperature increases they work better, the other panels output decreases with temperature.

You will need a regulator for your panel(s) this will ensure that you don't damage your battery(s).

If you are serious about understanding the solar systems (which in reality once you read up on them are very simple) I can't recommend the following book highly enough:

"Solar That Really Works! - Motorhome Edition" by Collyn Rivers.

He is an Australian multi disciplined engineer that actually knows what he is talking about, here is his website URL:

Cavavan and Motorhome Books by Collyn Rivers (http://caravanandmotorhomebooks.com/)

All the best, you will absolutely love having a compressor fridge that would probably run upside down as opposed to the headaches of having to run a gas powered fridge on level ground. :)

Hoges
30th August 2009, 05:34 PM
Quote: Do the old electrical equation ( volts x watts = amps? )

Almost :) actually, Watts = volts x amps :angel:

101 Ron
30th August 2009, 06:43 PM
I have a Jayco camper van which was factory fitted with one 64 watt unisolar panel and a waeco 110 litre 12 volt fridge.
other 12volt drains is internal filiment lights and a 600w inverter usually charging camera batteries and running a small DVD player for the kids.
( one light of about 20 watt is left on all night for the kids to find the toilet)
The panel is fitted flat to the roof.
Naturally one panel was not enough.
So I fitted another unisolar 64 watt......a good improvement , but I was still ending up with a flat battery after a couple of days.
The battery is a Gel 700cca size.
I have now fitted two 20 watt monocrystalline panels as well and thing is now just self sufficient on the East coast.
I have 170 watts in total.
I get about 7 to 8 amps in real terms for a few hours on a normal sort of day with about 2 amps every other time during daylight.
You can never have to much solar panel.
I know I could get more power if I angle the panels and park the camper in better locations etc............but I wanted to park and play.
I could go to more battery storage , but if you can afford it the panels are a lot less weight and at the end of the day you still need to charge them if you are set up in one spot for a long time.
Where you live and what season it is greatly affects how much solar.
Three cloudy days can stuff up the cold beer department.

101 Ron
30th August 2009, 06:52 PM
I highly rate the Unisolar for they will work if a shadow from a tree branch moves across the panel.
The unisolar have no glass in the construction and are lighter and harder to break.
The monocrystalline panel drop right off if any shadow is around.
The amphrous panels (I have some portable small ones , may be cheap , but the out put is very poor for the size and they are glass construction and easy to damage.

Tombie
30th August 2009, 07:08 PM
If you are serious about understanding the solar systems (which in reality once you read up on them are very simple) I can't recommend the following book highly enough:

"Solar That Really Works! - Motorhome Edition" by Collyn Rivers.

He is an Australian multi disciplined engineer that actually knows what he is talking about, here is his website URL:

Cavavan and Motorhome Books by Collyn Rivers (http://caravanandmotorhomebooks.com/)


Sorry, but having read his scratchings, I can tell you he has quite a bit incorrect...

Like Sol says "Engineers aint engineers......" :cool:
Not everyone with a piece of paper is right :wasntme:

land864
31st August 2009, 09:20 AM
Geez Hoges , you're a hard man :)

By background is mech services plumbing and I did add a question mark :angel:

Anyway hope this all helps Ean

Hoges
31st August 2009, 11:19 AM
Yeah... my son is passionate about his daily life of engines/airframes (helicopters) and wrestles similarly with avionics... I gently coach him occasionally of what's Watt...!! :eek::eek::D:D :wasntme:

land864
31st August 2009, 02:03 PM
Who's on first :D:D

isuzu110
31st August 2009, 02:28 PM
I struggled for several years to get by on just 80W of solar if I wanted to base camp for a week in queensland in summer. I run a 60L evakool fridge/freezer.

80 W certainly helped a lot but only stretched my run times to 3-4 days after which I'd be running the 110 to top the batteries up.

I aimed for 100W but ended up overshooting to 145W which is more than ample now. Got a 65W panel for too good a price to pass up.

I hope that 80W works for you. Good on you if it does. Certainly, if you go driving for say 30 minutes a day when camped you should be fine.

PhilipA
31st August 2009, 07:26 PM
Also get a BIG chain like I saw a bloke have at Lakeside camping at Ningaloo.
He had his Unisolar tied to his van with what looked like a 20 tonne chain!!! LOL.

Regards Philip A

awabbit6
31st August 2009, 07:57 PM
We have two 64 watt Unisolar panels on our camper trailer (http://www.aulro.com/afvb/camping-tucker-bush-basics/69547-solar-power-our-camper.html)and they work well. We are charging a deep cycle battery with them and run a Waeco 80L fridge, two 8W flouros and a water pump on our camper. So far, the two panels have just been sufficient. The only time we have had the battery go flat is after several days of overcast weather.
We bought the panels 12 months ago and at the time (and possibly still), there was no other panel with the same performance and durability. Unfortunately, I don't think that the panels are available at the moment. My understanding is that Unisolar have scaled down the production of the portable panels and put their effort into panels for residential installation.

handy
1st September 2009, 04:17 PM
Sorry, but having read his scratchings, I can tell you he has quite a bit incorrect...

Like Sol says "Engineers aint engineers......" :cool:
Not everyone with a piece of paper is right :wasntme:

That's your opinion which you have every right to.

I have only one of his books, & I can't find fault in it & that is from experience not just being an armchair critic.

Anyone with the amount of experience that Collyn Rivers has will always gain my respect & attention:


Caravan World
January 2002

Collyn Rivers knows his stuff - he's been a research engineer for GM, and specialised in measuring vehicle behaviour and performance. In the 1960's, he drive a 4WD laboratory-motorhome across Africa monitoring track conditions. He migrated to Australia in 1963 and subsequently founded the worldwide Electronics Today International magazine that was later to earn itself a global award.

With more than 20 books and magazines in electronics, business computing, communications and music to his credit, he later became Technical Editor of Australian Business and The Bulletin and also wrote the Federal Government's Guide to Information Technology.

Collyn has twice drive across Australia with his sculptor wife Maarit in a full on OKA motorhome. The couple's treks have included making it to the tip of Cape York, across the Simpson Desert and along most of Australia's inland major and minor tracks.

With 40 years experience in designing and using motorhomes and campervans, Collyn Rivers has now put his encyclopedic knowledge of the subject into print in a comprehensive work, The Campervan and Motorhome Book.

Collyn says, "There are tens of thousands of people travelling around Australia in caravans, campervans and motorhomes and the Campervan and Motorhome Club of Australia has around 26,000 members with its ranks swelling at the rate of 300 every month."

"For retirees in particular, this is a regular way of life, but despite the rate of growth in the following of the wandering lifestyle there's little independent information available about buying, building, converting or even using these vehicles."

He concluded, "The just published The Campervan and Motorhome Book will fill this need.".

Collyn Rivers' book deals with a host of issues germane to campervans and motorhomes and there's quite a bit that is relevant to caravans too. In the many appendices there is virtually no issue that he hasn't covered. Certainly his engineering background is a superb credential but best of all, Collyn has done it all himself and is still doing it, and he has represented a fine catalogue of experience in this comprehensive handbook.

There's mechanical advice, advice on tyres, advice on choosing a vehicle, building your own RV, gas, water and electrical systems including solar power, what medium of fuel to use, what to carry and how to prepare for a trip. There's also a lot of information on the economics of living on the road, something that is of utmost importance for those who have never done this sort of thing before.

flagg
8th September 2009, 07:36 PM
Looking into the uni-solar panels I found this:

Uni-Solar panel..A word of caution. @ ExplorOz (http://www.exploroz.com/Forum/Topic/4577/Uni-Solar_panelA_word_of_caution.aspx)

..interesting point to be made.

Crackerjack
8th September 2009, 08:21 PM
has anyone thought about using a small wind turbine instead, you see them on yachts occasionally

Bushwanderer
9th September 2009, 03:44 PM
Hi Crackejack,
Yes, you do sometimes see wind turbines on yachts, but generally on land they are less reliable than solar panels (unless you have a fixed system).

Best Wishes,
Peter

incisor
9th September 2009, 05:23 PM
That's your opinion which you have every right to.

i bought the book and it has some dam good stuff in it and it was well worth the cover price

BUT

my 2c says

what is good in theory aint always good in practice.

driving round with live lethal voltages in vehicles that have no form of warning on them for the sole purpose of obtaining a theoretical gain over using non lethal voltages is nothing short of the lowest form of selfishness i can think of.

people have already been very seriously injured by this sort of self centered drivel.

at least they could have the common decency to warn people they have live 240v on their vehicles so emergency workers and others can stay the hell away when things go bad.

any vehicle with an inverter and 240v charger on it should have a sticker like a gas equipped vehicle has too, in the hope that it will warn people of it's existance.

rant over...

Crackerjack
11th September 2009, 08:46 PM
driving round with live lethal voltages in vehicles that have no form of warning on them for the sole purpose of obtaining a theoretical gain over using non lethal voltages is nothing short of the lowest form of selfishness i can think of.

...

I think you need to get out more, In a news article a few days ago in England, a young man 2 days away from dying of cancer had his car nicked while he and his family where all inside, That is selfish.
His family kept it from him so he did not add to his worries, he died not knowing.