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Post Info TOPIC: total solar confusion


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total solar confusion


have just joined the forum, for a lot of reasons, but mostly to try and get some clarity on solar systems.

My needs are very simple, I just want to have a fridge for trips of over 3-4 days max 2 weeks away from mains, I may need to charge a laptop at a later stage. But I dont need power for lights or showers or microwaves or washing machines.

So, on the strength of giving notice of my retirement...yippee....I have bought a fridge.....a 2yr old engle 38lt elipse (there is only me) reported by engle to be the best thing since sliced bread and better than all the rest... yeah right!!!!    I got it for $2-300 under new inc cover & residule warranty....so i'm happy enough with that.  I'm sure you'all have something to say about it....but its done and dusted so the point is mute.

The question for me is how to power it.   Obviously while driving it can plug into the 12 volt at the back of the xtrail.  Although there seems to be some question of some fridges cutting out??? if the feed level is too low or fluctuates or something... When stopped I can apparently then:

A.   Leave it unconnected, having prefreezed the unit, added a couple of icepaks and carfully planned storage and access, should give me maybe an extra day or so, so why not just use the esky.

B.  Get a battery.  

C.  Get Solar.   

D.  Get both.   

So choices .....I'm not planning to wire up a battery to the xtrail....i cant do it myself, know no-one who is capable....and don't want to spend the money on something that is only for the next couple of years till I upgrade.

Currently I sleep in the back, and have an enclosed awning off the tail which works well for now.

So due to space restrictions I cant fit a large heavy battery or large solid panels. I will often have a kayak or 2 on the roof so don't want to permanently mount cheaper solid solar, and there seem to be some issues with overheating anyway.....

In the worst case scenario I will be away from the car for up to 3 days, The fridge will be in the closed up car, so ambient will be quite high and will obviously need power to keep stuff at least cool.

From what I understand a single battery, even lithium wont give me this sort of capabality.

Engle state that a blanket can plug straight into the fridge.....????   goodoh,  but what happens at night when im not there, does the fridge power off and restart on the resumption of a power feed with sunrise (or a bit later)  - or do I need some sort of control hub....or do I need the battery in the middle of the chain to keep the feed going thru the night till the blanket starts to feed again.

All my research....i'm leaning towards lithium120 battery and a solar blanket 90......suggest these will be the most practical all round.......however many $$$$$$$ later.

so, if I can delay the purchase of one of these till a bit later, would be good.  

Engle promote a range of blankets from the US that read well....and there is an chance of a saving there if I move on it..

So my question is,  can I just use the blanket when I'm not there to monitor it (forget security for now) or do I need them both.....

 

bit of a rant I know....but its my intro as well as a querie.....



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Solar plus a battery is the way to go, but the ones you mention are about the most expensive way I have yet seen to achieve what you want.
A conventional folding solar panel (as big as possible) plus an 120Ah AGM battery plus a method of also charging it from the car will give you good performance and reliability at a much more reasonable cost.

Cheers,
Peter

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OKA196, 4x4 'C' Class, DIY, self contained motorhome. 960W of solar, 400Ah of AGMs, 310L water, 280L fuel. https://www.oka4wd.com/forum/members-vehicles-public/569-oka196-xt-motorhome
 

 



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Work out your usage . Then double it . Get solar,regulator and battery/s then your done . Depending on size and weight then consider a generater etc . IMO with low load things like fridges, TV etc . Purchase 12v . Makes for easier low cost usage than going through a 12v to 240V inverter . Then use gas to heating water. Or genie for electric jug . Nothing is more anoying on overcast days seeing your battery voltage go go down . Solar is relatively cheap now especially if you fit it yourself .. On roof or folding ..

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thanks peter, I agree with your suggestion re the folding panel & AGM battery.

but..carrying the stuff around is a really big part of the issue, large solar panels would completely cover my bed area during transit,  if I had an overnight layover I would have to move them outside to sleep, inconvenient and irksome with a high risk of damage to them and me, lower back doesn't like that bent over lift position.

Also I don't want to spend on wiring up this xtrail, when in a couple of years I will have to redo it all with a more dedicated vehicle, though not a nice truck like you have....

In theory the money I save on not needing to double up at the auto elec will help to offset the more expensive cost....just a little bit...I've still to compile a comparison budget on the different types available, I know this choice is the most expensive....

But the question remains, what happens at night when i'm not there to fick the switch or whatever is required.....will my fridge restart in the morning from solar alone, or do I definitely need the battery and some controller thingy to keep it chugging thru the nite.....

thanks for your reply....happy trails.....nuby



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thanks aus-kiwi  for your comments......a generator is not for me......the roof mount is out, cause of the kayak and Ive got a sun roof on the car....the folding panels are too big and unwieldy for my current set up.....but I will double check my requirements,  fridge and laptop charging are the only things that I will need. Lighting is independent solar, hot water is solar bag, cooking is gas....its a very basic, no frills setup....for me its all about the getting away, not so much about taking it with me....

thanks for your reply....happy trails....nuby



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Grab some heavy cable / welding cable etc and run under chassis to battery from your main motor battery . Just cable tie so cun be used or swapped into any vehicle . In some cases it can be threaded through chassis rail ? Use relay as isolater switch so there's no chance of flattening starter battery .

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Whats out there


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My 20 cents worth. A 10Ah lithium battery, light weight portable panels that can be slide up under the roof mounted kayak when not needed. The whole lot is plug and play using Anderson plugs so you can just unplug it from this vehicle and plug it into the next. The battery weighs around 17.5kg, the panels about 3 kg, the whole set up probably about $1500 all up and you would be self sufficient at the minimum loads you are looking at powering. The system can be added to at any time, not a matter of throwing away what you have, you just add as needed.
The problem with the fridge shutting down when there is no solar but starting up again when the solar returns is the heat trapped in the vehicle could defrost the food, then refreeze and you would be none the wiser and end up with food poisoning. You need a battery that is mall and light, recharges quickly and can give all it has if needed to keep the fridge going even if the sun doesn't show for a day or two.
I would recommend adding a few fans that mount in the wound up windows to pump the hot air out, reflective type bubble wrap insulation over the windows to keep the sun out and this should keep the vehicle interior cool enough for the fridge to work properly and cycle on/off to maintain temperature and that will also save on battery power. In a hot closed up vehicle the fridge doesn't stand much of a chance in keeping stuff cold, even if it runs flat out all day, better to keep the car cool so the fridge has an easier job to do.

T1 Terry

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Thanks terry, keeping the car cool is part of my solution... Have already sourced an external windshield shade, I use those mesh covers over all the windows for sleeping anyway, and can easily suplement with sunshade offcuts, I'm planning on running a smallish tarp over the roof racks and back spoiler so I can leave the sun roof ajar and not worry too much about rain. I know this will keep the inside temp down. Ideally the solar gear would then attach above the tarp on the roof rails. The preference for the solar blanket was the ease of getting it up there without dropping, security wise, I was banking on chaining it to the rails or something and running the power cords thru the roof... The other reason for the power blanket is it's apparent ability to charge, albeit not as efficiently, in all light conditions, including somewhat overcast days. I'm taking that to mean a little shade from trees which in turn will help with inside temps...one of the other interesting aspects of the blanket is it seems to be less dependant on perfect angle to the sun to produce a reasonable charge, rather handy for the static setup I'm considering... Good to hear you agree with lithium... they appear to be far superior in every way... I'm hoping 120ah will be sufficient.... This all seems like an expensive indulgence just so I can have a coldie with my cheese and crackers after a lazy 3 day paddle up the Noosa for the Aust day weekend, but a few more days in camp after and it will save the hassle of a longish drive out to pick up ice supplies, and that's well worth it. Thanks for your comments...happy trails...nuby

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Aus-kiwi...lt sounds simple, I really would like too....but as a 64 year old woman... cop out I know... who's managed to get thu life with only needing to change light bulbs and rewire the odd frayed plug, and they don't even fray anymore, I can't see me rolling around under the car threading cables thru the chassis...etc...yeah I could maybe do it...with a real lot of inappropriate language...and an awful lot of time...so best to leave it till the next car, and pay someone else to practice their language skills...thanks for the input though...every bit helps the understanding, even if not the doing. Cheers nuby

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Surf bars for canoe?.

How much room behind sliding roof? on surfbars.

2 lengths of angle aluminium, across roof of car. behind sunroof
Panel fits between them. with 2 locking pins at rear to stop sliding right out.

2 x Caravan shop Extending legs. length to suit, with fittings at top to clip/pin/bolt onto outer end of panel.
Legs extended to height req'd. Having panel standing out at side (either side)
not fr or back of car.
and behind drivers door so no obstruction to.

You'll have canoe on top. sunroof usable.
Panel slides out from under rails and extended legs on ground,
support the panel at whatever angle to suit.

SImple, easy and under 1\2 day work.

Somebody here will probably volunteer. for a coupla coffee's or a drink?.
Coupla women together will sort it real quick. hey.

I will if you anywhere near Yeppoon QLD.
All us old farts have plenty of spare time.

Wouldn't bother with Lithium or any fancy battery, till you established with whatever.
and KNOW what size.power you need and can fit.
You could end up with wrong one/size
98% of us use Wet or gel/AGM at most.
But temporary. I'd think twice.
Wet cells fine....

Just put in rear. and have an ELECTRONIC unit between them to charge it from car.
The solenoid units do NOT fully charge. only equalise at most.

 

IF NOT using that battery as a second charger.

You do NOT need heavy starter cable to it.

I only have 8mm wire to my two in tub. and use long jumper leads if need starting power.

and a micro sw on dash, to activate charging from when car starts out.
not when car battery at set charge.

Fridge insulation.
Find an insulation merchants. and buy a mtr or so of 17mm Duct insulation.
solid grey with Silver ally outer coating.
Cut and fold to fit round Engel.
Wrapping with duct tape.(Nothing sticks to outer face)
and have one end/side cut to form a flap over top of fridge
as a lid.

My Waeco 80ltr. up in top end. with flap down in rear of Patrol.
When lifted it has a full coating of condensation over complete fridge/freezer lid.
IN rear of car at DARWIN.

That... is insulation. Magic stuff.
Just cut hole where fan/s are to let it out.



-- Edited by macka17 on Monday 31st of October 2016 04:31:31 PM

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Hi nuby,

If I understand correctly you may be away from your vehicle for up to 3 days at a time so I would think that any solar panels (portable, fixed or solar blanket type) set up with the vehicle would not still be there on your return. A decent well made icebox capable of holding 6-10 litres  of frozen block ice (frozen in 2 litre milk containers) + what you want to keep at  refrigeration temperature would remain suitably cold for up to 7 days or more if the icebox is left  unopened in the vehicle - this may be an option for you to consider & you could sell your fridge, have money left over & not have any more  expenses other than the cost of freezing your ice block containers each trip.

Regards,

David.



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Hi Rubysmile

Here are my thoughts for your thought biggrin

Very expensive to do what you are proposing for some small gain. But that is your call. The items you propose to consider, a solar blanket and lithium battery, are very expensive too but again if you see the value that is your call. The RR solution to a mini minor problem IMHO. confuse

If I wanted to do what you propose, and looking for 3 days, I might consider this for a budget solution. Forget the solar as it does not suit you to carry or set up and the theft risk is high. Go for a couple of AGM batterys of sufficient capacity to get the 3 days at 50% capacity drop. They would sit OK in the rear floor wells and are sealed. Then charge them from the car alternator during the trip there(assume a couple of hours drive). Use a VSR to handle the charging through some good cables. The fridge should have a seperate voltage cut out to switch it off so it does not kill the batteries just in case you paddle slow, as the inbuilt one is set too low.

With this setup you can park in the shade to keep the car cool and the cost will be reasonable. Not much work to get done for setup either. Put some water bottles in the fridge to take as much space as is left so that will help, and some extra insulation(blankets) over the outside toowink.

Cheers Jaahn

PS Terry I guess your 10AH battery should be 100 ?



-- Edited by Jaahn on Monday 31st of October 2016 08:18:53 PM

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Like runing a cable through to boot etc is an issue ? I am of similar age . Also the storage on roof won't totally restrict solar . Your looking for reasons not to !! A 100 amp hour keeps our 60 litre fridge freezer going for 3 days easy . Once cold ..

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Hello nuby

I would just like to say, welcome to the forum

I am not a techie but I can see some of your problem, so it is a pity that you do not have anyone to wire up a system for you.
Perhaps some members from your area, could assist when you decide what your requirements are

As daffyfrancis has already said, due to room constraints, an icebox may be the way to go, as you will not require a battery or solar panel



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Tony

It cost nothing to be polite



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Regardless of what you do/buy/use.

Get that 17mm ducting insulation hard sheeting. Stanley knife and roll of duct tape.

It really does insulate. fridge or ice box, Then sort out what you doing.

Go on net and ask/look.

We basically, in relation to. only have a few old farts on here,

that in general, are only wondering about things themselves.
Me included.
And I've been vanning and solar for over 50 yrs.

The knowledge on net is amazing.
Just ask.
Fridge forums. solar forums. Engel forums. car solar etc.

Whirlpool, and Caravaners forums are /have a lot of good. old info on them.
Just ignore all the b/s in van forum.



-- Edited by macka17 on Wednesday 2nd of November 2016 05:59:16 PM

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hi Ruby,

Flat flex solar panel can be stored and carried easily . eg 2 x 100 waters a few kgs each
200watters can replace around 50ah on an average solar day
Given u are mounting the fridge in a hot environment 40ah consumption maybe occur
plus extras charging etc
Solar panels pad locked to car with a security cable . Padlock each end


An Agm of 120ah capacity 50% usable or suitable sized lithium .
Will a big enough battery mount in the engine bay [ 2nd batt] or would it suit to have it in the back
Lithium might be lighter if u have to shift it around .

swamp



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hi everyone, thanks for all the advise, am rethinking all options...had a chance on the weekend to inspect a couple of setups re security.

things im pretty certain about....

will get the insulation sheeting,
wont use icebox for long term......have an everkool fibreglass icebox with frozen milk bottles already.....a week in the car at kosiosko at xmas didn't work... though when I do use it I will wrap it in the insulation sheeting rather than a sun shade.
wont wire up the car, already have std 12v outlet in back of xtrail to run fridge when driving
don't need to charge battery when driving......in the short term....

still uncertain re solar blanket and lithium choice...considering semi-permanent hard panel on roof racks.....

cheers, nuby



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