What Will My Caravan Appliances Draw?

Planning a caravan or camping trip around the country and wanting to know which appliances you can take with you and comfortably run? Researching battery & solar products for caravanning and camping? Looking for real life power draw examples of popular caravan appliances? Like rooftop air conditioners? This blog answers all your questions!

 

How To Work Out Your Power Draw:

To calculate the power draw of each appliance, refer to the product specifications or check the data plate on the appliance itself. For products that run directly from battery power (usually 12V appliances) it is easiest to refer to the product specifications.

Look for the “average” amp hour (Ah) rating. For example, the power consumption of the Dometic CRX110 fridge is listed as:

“1.2 Ah/h (@12 V, +5 °C Fridge, -17°C Freezer, 25 °C ambient temperature) setting 3”.

 

What Does All This Mean? Let’s Break It Down:

The manufacturer at Dometic has tested the fridge in an Ambient Temperature (outside temperature) of 25°C. They have changed the fridge to setting Number 3 and recorded the average power draw. The fridge on average draws 1.2Ah per hour..

As your fridge runs for 24 hours, the above power draw equals 1.2 * 24 = 28.8Ah

Therefore, this fridge on average draws 28.8Ah per day.

It is important to note the difference between factory testing and real-world testing. It would be nice if the ambient temperature was 25 degrees every single day, but we know that the temperature can soar above 40 degrees in summer. And if you are like me, you will want your beers cooled down to below 5 degrees.

We will refer to the Trip In A Van video regularly throughout this blog post as they are travelling guru’s. Their CRX110 is shown to draw uapproximately 1.95Ah and up to 4 - 4.5Ah in some conditions.

For 240V appliances, you will need to check the back of the appliances and crack out the calculator. For example, a basic coffee pod machine will display 1300 watt / 240V input on the bottom of the machine. To power this at an off-grid campsite, you will need to connect it to an inverter which is in turn, connected to your battery. The current draw in amps for this product is calculated by dividing the wattage (1300) by the battery voltage (12V). Therefore, the pod machine will theoretically draw up to 108amps on full power.

Once again, our real-world testing slightly varies. The guys at Trip In A Van tested their pod machine, which was drawing around 90amps but then it quickly dropped down to 13amps after the water was heated.

The table below is a handy resource to help calculate your daily power consumption in amp hours. The major contributing factor to daily power consumption is not only individual product current draw, but the hours you plan to run each appliance i.e a coffee machine is a high current appliance but only runs for 5 minutes, and the inverse is true for a 12V compressor fridge.

 

What is the difference between Amps and Amp Hours?

Amp Hours are simply amps Multiplied by hours of use. A Fridge that draws 2 amps and runs for one hour is drawing 2Amp hours (2Ah). The table below is calculating the daily power consumption of each product by multiplying the amps by the daily hours used. Some high current appliances (toasters) are only run for a couple of minutes and some low current appliances (12V fridge) are run 24/7.

 

List Of Popular Caravan Appliances And Their Power Draw:

Trip In A Van Testing:

 

Trip In A Van Testing Summary:

 

Appliance: Amps: Hours Run Per Day: Average Daily Consumption:

CRX110 Fridge*

2A

24

48 Ah

Dometic RUC 8408X Compressor Fridge & Freezer 224L

4A

24

96 Ah

Washing Machine

7-15A

15-30 minutes

8 Ah

750W Toasted Sandwich Maker

40A

5 minutes

4 Ah

Toaster

45A

5 minutes

4 Ah

2000W Induction Cooker

Max 100A

30 minutes

50 Ah

Coffee Pod Machine

Up to 90A

5 minutes

8 Ah

Milk Frother

25A

2 minutes

1 Ah

Microwave

93A

5 Minutes

8 Ah

Kettle

147A

5 minutes

12 Ah

12V Water Pump

6A

1 hour

6 Ah

Rooftop Air Conditioner

45 – 55A

Up to 3 hours

50 Ah

Other Combined Loads

3A

24

72 Ah

*CRX110 is running off of battery in ute canopy.

 

With the exception of the CRX110, we can use the above Trip In A Van testing to approximate their daily power draw. To calculate this, multiple the amp hours by the hour runs per day.

For example, the daily consumption of the RUC8408X equals 4*24 = 96Ah

Another example is the microwave, which equals 93*(5/60) = 7.75Ah. For this calculation we have just converted 5 minutes into hours by dividing it by 60 minutes.

There are several resources on the internet to help you calculate your daily consumption. For example, the guys at My Generator have put together a solar panel calculator, which allows you to plug in the average current draw and how many hours run per day.

Using this calculator, we found that running all of the above appliances will draw 319Ah per day, which is A LOT. However, it is unrealistic that you will run all of the above appliances every day.

This is why it is so important to have sophisticated monitoring tools as part of your power system. A quality battery monitor allows you to maintain a pulse check on what is coming in and going out of your system. We highly recommend the Simarine Battery Monitor, which is found in an extensive range of the Enerdrive Battery Bundles.

The other side of your daily power consumption is your charging inputs, which offset your power draw.

Trip In A Van have 720W of rooftop solar, with a max input of 30amps per hours for 4.5 hours of full sun.

This equals 140amps of power going into their caravan battery setup each day (in perfect conditions). They also run an Enerdrive 40A DC to DC Charger which inputs 40amps per hour while driving.

 

How Much Power Does My Caravan Rooftop Air Conditioner Draw?

Caravan Air Conditioners are 240V appliances. To calculate power draw you will need to find 240V AC input in watts or amps. This is not to be confused with the cooling capacity or AC output, for example the Dometic Harrier Plus has a maximum 240V AC input current of 7.9A. This figure is the current draw at 240V, to calculate the current draw from your caravan battery system convert the 7.9A to Watts.

7.9 x 240 ≈ 1900W

1900W drawing form 12V ≈ 160A

Therefore, this air conditioner theoretically draws 160A from a 12V system, on full power and the coldest setting.

The Trip In A Van real-world testing has uncovered some fascinating revelations about the power draw of the Dometic Harrier Plus Rooftop Air Conditioner.

While set to 16C on full fan, the air conditioner only pulled between 45 – 55Amps from their 12V lithium caravan battery setup. One reason for this would be the lithium battery is above 13V which will lower the current. But that will only account for about 20Amps. We do not really know why this air conditioner is drawing such a low current from this system, but it is likely due to the inverter technology within the Dometic air conditioner keeping it as efficient as possible. We have seen plenty of examples of this in other installations and on the workbench at Enerdrive.

In Summary, we recommend installing an Enerdrive Lithium battery (minimum 200Ah) system with a minimum 2000W Enerdrive inverter if you are looking to run any of the inverter style Dometic roof top air conditioners. The low current is phenomenal and allows you to pop the air conditioner on for an hour to get the van cooled down on a really hot day. 

The Trip In A Van power system is a beast. They have opted for the Enerdrive Pro Series 400Ah with a 3000W Inverter Charger.

Some other popular bundles to pair with a Dometic Inverter Roof Top Air Conditioner are:

Do I Need An Inverter?

If you want to run any 240V appliances you will need an appropriately sized inverter.

 

How Much Solar Do I Need?

Solar is super important in maintaining your charge levels of your power system. Solar panels are relatively cheap compared to the rest of your power system. Essentially, fit as much solar as you can on the roof and pack a portable solar panel too. 

 

Other Noteworthy Appliances That Aren’t Included In The TIAV Video:

Here are some other critical appliances and their power draw while running from 12V:

 Appliance:

 Amp Hours:  

 Laptop Charger

4A

 Phone Charger

0.5A

 Tablet Charger

1A

 12V Fan

3.5A

 12V Television (Small) 

6A

 12V Television (Large) 

10A

 

Overall:

The Trip In A Van video featured in this blog is an example of a high end off-grid caravan battery setup. For running high current 240V appliances such as air conditioners, kettles and toasters most customer still choose the convenience and inexpensive option of an inverter generator

For under $1,000 you can purchase a generator that will comfortably run these types of appliances.

For the typical off-grid or semi off-grid battery installation we recommend a 100-200Ah lithium battery and charging bundle.

Hopefully, this guide can assist you to calculate your power consumption on both 12V and 240V. If you need further assistance with this or other caravan and RV related enquiries, please contact us on 1800 787 278 or via our live chat at the bottom of your screen.