Fridges & Batteries
Selecting the right fridge can be a bit of a daunting task, they are expensive, bulky and require power. There are many options as to where you can store your fridge, in the 4WD, on the back of a ute, in your camper trailer and so on.
Depending on where you are travelling to, i.e. hot or cold climates, it can make a huge difference to the efficiency of the fridge. When the ambient temps are cold, like in the zero degree area, your fridge will reduce the amount of power it draws compared to being in a hot climate at say 35c, where the fridge will work hard to maintain temperature, and therefore be a bit of a drain on your batteries.
When looking at fridges, be aware of what your fridge will draw amp wise from your battery. As an example, a 80ltr Waeco fridge freezer will draw approx 6.8 amps, where as a 40 ltr Engel will draw approx 2.6 amps when running. The size of the battery you are using also comes in to play especially when the vehicle is turned off and not receiving any charge.
Auxiliary batteries come in a range of types i.e. Gel, AGM & deep cycle for example.
A battery with high amp hours will help your cause greatly, a deep cycle battery will have a much better performance efficiency wise with fridges, as it will draw down amps at the same rate throughout all voltage levels until it can no longer hold charge. An AGM battery for example that is a combination of crank voltage and amp hours, will draw efficiently until it reach's about 12 volts, at this point the amp hour side of the battery will quickly dissipate and become ineffective to the point where the fridge may even cut off. Now there are millions of forums regarding the battery
& fridge debate, but in a nutshell, choosing the right fridge and battery combo is something you need to get right, or you may end up with warm beer and nobody wants that.
There are many ways to charge your batteries to keep your fridge fresh, obviously when you are driving your car the alternator has the job to charge to the battery. On longer drives even while the fridge is turned on, you can probably get that battery fully charged again. Having an inline charge system like a CTEK or Redarc charger for example will greatly increase the efficiency in getting the battery fully recharged and ready for time at camp with no charging. Solar panels are great when at camp, but you need sunlight to keep a charge going through the battery. If there is power available and you have a charger, you can always recharge at camp as well. For the most part, the idea is to get a fridge set up that allows you to camp anywhere at anytime and not get into a pickle when there is no 240v power available.
In the past we have used a dual battery set up in our trucks and it has worked fine on the shorter weekender type trips. As we have progressed to longer outback stays in Cape York, The Simpson Desert and trips to the top end / Kimberley regions, an extra upgrade was needed to run 2 fridges in HOT climates.
Now without getting into a debate about who has the best fridges, we found that the hard plastic type fridges in the larger size i.e. 60 & 80ltr, this fridge type will struggle in hot climates (35c)
Even with fridge covers and solar shielding on the rear windows of the cruiser, they just struggle to hold temp and as a result, the fans are constantly working, drawing power, and pushing hot air around the cabin.
Smaller Steel construction fridges like the 40 ltr Engel for example are in our opinion, are superior all round. They draw less amps, stay at temp, and deal with the climate more efficiently.They are also very well built with a superior quality outlasting all competition over decades of time. They don't need replacing after 5 years either.
Coupled with a third dedicated 150 amp hour Full river deep cycle battery in the back, and a REDARC 1225 inline charger which receives power from our dual battery system up front, our fridges: one running as a freezer and the other as a fridge, draw less power than one big plastic construction fridge and allow a family of 4 to easily fit approx 3 weeks of food in them.
If travelling daily, the inline charger will keep the batteries topped up. We can sit for approx 3 days without charging batteries depending on how hot it gets. Add a solar panel and we can sit for nearly 10 days before we would need to turn the car on and go for approx a 1-2 hour drive.
When travelling for long periods like a month to 6 weeks, or even longer, we have found this extra set up of a third battery, inline charger and steel construction fridges to work best for us.
Our second Auxiliary battery has never had an issue, as it runs all other accessories inc camp lights, winch and USB's etc etc. We also have this battery connected to the main battery system in case we ever have a dead start battery. At the flick of a switch, we can start the car off the second battery as a back up. That's not really possible to do if you run 2 fridges off that 2nd battery after sitting around camp for 2 days as well, there just won't be enough crank in them to start the car, so hence the 3rd battery system covers all bases and gives you some great options.
Whatever you do, remember that these ideas do come at a cost so you want to get it right the first time. In our opinion, if your going to travel to Hot climates for longer stays, upgrading your fridge and battery system will make life much more enjoyable during your travels, especially if travelling as a solo family.
Must be time for cold beer !