Does This Sound Like A Plan?

Oct 1, 2013
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After lots of help and advice on here and other places, I've decided on a plan.

This is mainly aimed at when I'll be in driving through Spain and living in Lanzarote, so plenty of sunlight.

1) I'm gonna stop the van battery powering the fridge and connect it to the leisure battery.

2) Gonna add a second leisure battery (110 AH)

3) Gonna fit a split charger relay so that leisure batteries get a charge from the alternator. Not going for a fancy one as want to run the fridge when parked,

4) Finally hoping to fit a 200W solar panel.

We only ever run the lights and water pump. I have a 300w inverter to charge phones and laptop.
So nothing major to drain the batteries.


Questions ...

A) While driving through Spain, will the combined charge from the split relay and the solar panels allow fridge to be used while driving and still keep batteries fully charged ?


And, in Lanzarote, assuming that we will be setting off into the 'wild' with 2 fully charged batteries (220AH). (We can hook up to EHU at my dad's.)

B) In Lanzarote, will the 200w solar panels put enough (extra) into the leisure batteries to power the 100w fridge for a 4/5 days at the beach?

C) Can I also run a smaller 65w beer fridge which I may just wanna run occasionally?

D) If I get the fridge to work off gas, can I run the 65w fridge just off a 100w solar panel ?

E) Can somebody recommend a decent 200w solar set up?


Thanks in advance


Yorick
 
Last edited:

Chris

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I am bumping this for you.

I can't even begin to help but I am sure a Funster can
 
Sep 23, 2013
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Yorick

What are the make & model of the two fridges?
 

hilldweller

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B) In Lanzarote, will the 200w solar panels put enough (extra) into the leisure batteries to power the 100w fridge for a 4/5 days at the beach?
Yorick
It's not that easy.

That 100w fridge, is that the estimated 24hr rate or just running rate ?

A 100w solar panel on the roof might give 100w at noon on the equator. At 50deg north it will be 76w at noon ( sin(50) ), much less either side of noon. It will depend on how many hours sunlight.

Certainly get 200w and two batteries then suck it and see, it's the only real way.

Yes, gas fridge is best.
 
OP
Yorick
Oct 1, 2013
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Yorick

What are the make & model of the two fridges?
The main fridge is a Dometic 4200 series.
Manual says ...
input
230v - 105 watts
12 v - 100 watts
Energy consumption 2.3 KWH

The beer fridge is just a little one from Woolworths. It says 65w on the label
 
OP
Yorick
Oct 1, 2013
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It's not that easy.

That 100w fridge, is that the estimated 24hr rate or just running rate ?

A 100w solar panel on the roof might give 100w at noon on the equator. At 50deg north it will be 76w at noon ( sin(50) ), much less either side of noon. It will depend on how many hours sunlight.

Certainly get 200w and two batteries then suck it and see, it's the only real way.

Yes, gas fridge is best.
So it doesn't sound too far out eh ? Good

And the manual says the gas option on fridge will use 0.24 Kg per 24 hours
 
Sep 23, 2013
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The Dometic 4200 is a 3-way absorption fridge, so it will be running on gas or 230V mains when stationery. It only cools on 12v while you are driving. So you can ignore it when calculating battery capacity. It may still use your leisure battery to ignite the gas & power the interior light, but that's trivial.

The little one may well draw the 65W more or less continuously. At midday in Spain, a 100W panel should just about keep up, from what I remember about panel outputs, but the rest of the time the fridge will be drawing between some & all of it's power from the battery.

Depending on how much you use it, my guess is that you should get your 4 - 5 days with two batteries & a 100W panel. With a 200W panel, you should be fine indefinitely during a Spanish summer. If you start to run short, you will either have to sacrifice salad space in the main fridge to make room for the beer, or drink warm beer. I don't suppose that question really needs asking really, does it? ;)
 
Jun 5, 2012
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yorick if as i have stated if it,s power u want why not adapt a bike starter fitted under front wheel,s connected to a power boosting charger, run as needed just a thought
 
OP
Yorick
Oct 1, 2013
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Sorry. I'm
yorick if as i have stated if it,s power u want why not adapt a bike starter fitted under front wheel,s connected to a power boosting charger, run as needed just a thought
Sorry being thick. Not make sense.
 

sedge

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I know I'm just the pillion, not the rider (me little legs aren't long enough for Pete's bikes, even if I could ride em) BUT your possible reasoning for some of this really really puzzles me.

You know when you are bimbling along at more than tickover in a motorised vehicle of most kinds, I have always understood that the action of the fan belt going round, somehow recharged the vehicle battery whilst said bumbling is in course. So as it's a 'side effect' if you like of the driving in the first place, this battery charging is 'Free' ie it costs you nowt and it doesn't detract from that battery being used to power not only the engine but whatever else you happen to want it for - lighting a fag, keeping the charge in your SatNag, or whatever.

The fact that it will also run the fridge in your MoHo or the caravaln you are towing at the time, is a bonus. A FREE bonus.

So I don't understand why you don't want it to? I don't see what benefit you might gain from doing this?
 
Dec 12, 2010
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Hi Sedge, you know the old saying about a free lunch, well the same thing applies to alternator produced electricity, there is a cost involved though I'm not sure how much. Simplest thing to compare it to would maybe be how your mpg goes down if you put the air conditioning on ? If you're drawing power to run something, you have to produce that power from somewhere in the first place.
 

sedge

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Well - I do appreciate that, but won't it cost something to actually convert the fridge wiring to run off the other battery/ies ?

What's the power consumption of the A/C in comparison to the fridge - and you could say 'I never go above X Revs at any time when driving the vehicle, cos it will reduce my MPG' - you just go at whatever speed is comfortable for you and safe at the time and if you need to accelerate suddenly to do the manoeuvre in that fashion - when does MPG enter that equation?
 
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