The milk’s gone off, everything frozen has thawed and you guys have been out fishing all day!


Those words clearly summarized my first attempt in going camping with a 12v fridge and solar panel combination. My wife was clearly not impressed and to be honest, that camping holiday was a disaster. I was ill-informed, ill-equipped and I spent most of the holiday shuttling backwards and forwards to friends with powered sites lugging heavy batteries and chargers.


The setup I had simply did not work- even under the best conditions.


On my return to Melbourne I was determined to investigate this topic further and subsequently spent many hours talking to manufacturers and suppliers of solar panels, fridges and batteries.


This has not made me an expert on the subject but with some of my new found technical knowledge behind me and ten or so years camping for a month each year on an un-powered site and conversing with dozens of other campers using solar/12v fridge combinations I may be able to help you avoid my initial mistakes.


I remember a doctor friend who once said that there is a point in medicine where  its no longer a science but an art form! to a certain degree the same can be said about this subject. We can control the technical aspect but we can’t control the most important element, the sun!


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VERY IMPORTANT

First determine whether you intend to use the fridge occasionally on a short term stay. i.e. long weekends [3-4 days], or for longer stays of a week or more.


SHORT TERM [3-4 days]

A 50Lt to 80Lt fridge will require a 100w or preferably a 120w solar panel and a 100AmpHr battery as a minimum.


LONG TERM [1 week or more]

A 50Lt to 80Lt fridge will require two 80w solar panels and sufficient batteries to hold 340AmpHrs as a minimum.


Some may argue with the above figures however as I mentioned before we can t control the sunlight, its duration or clarity and we are preparing for the worst case scenario not just hoping for the best.


DEFINITIONS


The Solar Panel

The solar panel simply harnesses the sunlight, converts it into energy or power and stores it into a battery or batteries.


The Regulator

The regulator limits the amount of power the solar panel is putting into the batteries. Its function is to stop the solar panel from overcharging and therefore damaging the batteries.


The Battery

The battery is the store room of power. It receives power from the solar panel, stores it and disperses it to the fridge as required.  

The Fridge.

Here we are talking about portable fridges which work on 12v power. Most work on 240v as well but that does not concern us for the purposes of this article.

 

Some smart fridges are designed to work on either 12 or 24v and will automatically adjust to suit. The Waeco-C-F-80 is one of them. However all of our calculations and set-ups will be based on 12V systems.


 Duty cycle , when referring to the fridge, means what % of the the time the motor of the fridge is working over a 24hr period. Just like your fridge at home the motor only works in order to keep the contents at the desired temperature which you have set.

NOTE*the bigger the solar panel the more power will go into the battery. The bigger the battery the more power it will store. The bigger the fridge the more power it will draw from the battery.








More.........




TIPS and TECHNIQUES: SOLAR PANEL DIY  by George Linardos

SETTING UP A SOLAR PANEL/BATTERY

AND 12 VOLT FRIDGE SYSTEM

Download Printable PDF Version (4 Pages) Click Here