Have you ever wanted to venture out to the Great Outdoors but don't know where to begin? One of the things to consider when creating your unbeatable rig or campervan is how much power you will need to keep devices charged or run essential appliances. The best way to learn exactly what to expect is to get advice from someone who has been through the journey. We invited Grant and Linda from My Aussie Travel Guide to share their experience setting up 12V appliances off-grid.
Powering 12V Appliances Off-Grid: Advice From Aussie Tourers
When we (Grant and Linda) first started out setting up a vehicle for touring many years ago, our approach was very hit and miss. We spoke to a lot of salespeople who all pushed their ideas and products, and we ended up with a very mixed bag of 12V off-grid appliances products that "sort of" worked. But we still found ourselves running short on our total power supply.
With the benefit of hindsight now on our side and insights gained from many trips to some far many trips to some far-flung places, we feel like we can now help others avoid some of the pitfalls and mistakes we made along the way. There’s a lot of information out there about 12V off-grid appliances and setups, and it can be too easy to get caught up with all the hype.
Begin By Working Out Your 12V Power Requirements
It’s important you take the time to develop what your 12V power requirements will be when looking at your essential needs and your wish list.
1. Determine Your 12V Off-Grid Travelling Style
Here are some simple steps we followed when designing our setup. Ask yourself these questions to help you decide the type of travelling you want to do.
1) How will you travel - Will you tow a camper or caravan, live out of your vehicle using a tent or stay in cabins?
2) Type of touring – Do you aim to live off the grid, or do you plan on staying in service towns?
3) Time on the road – Are you considering regular weekends away or a two-week road trip vs an eight-week remote desert crossing?
4) Type of traveller - Do you want all the comforts of home with you such as refrigeration, lighting, and electronic equipment (eg phones, tablets, cameras, etc.)?
5) Stay longer or move on - Will you set up and stay put for days on end, or will you be moving daily? This is important for how you recharge your batteries.
Of course what works for you today may change down the track, so at least consider you may want to expand your setup in the future.
Answering those questions put us in the category of remote, long term, self-sufficient, vast distance travelling, and travelling with some comforts from home.
2. Work Out What 12V Off-Grid Appliances You Will Need And How Much Power They Use
Let’s explain the process we took to working out the loads, recharging requirements, and the design for the 12V off-grid system we came up with.
The first step was to work out the 12 V off-grid appliances we would travel with and their loads. We listed out all the things that would need power and charging, iea 12V fridge/freezer, phones, lighting, torches, cameras, video cameras, tablets, laptops, navigators, water pumps, and battery powered tools. Then there were creature comforts such as stereo systems, fans for heating and cooling, and what 240v appliances we would like to travel with.
Dive in deeper: Building a camper trailer power system
3. Find the Amps or Wattage Of Each 12V Appliance
Now when you take a look at most 12-volt items, they will have the amps or watts usage labelled on the product. Determining the total amps we would consume allowed us to calculate the Amp Hours (A/H) we would need covered by battery capacity. For example, if our total daily usage was 60A/Hs, you’re now in a position to talk about battery size, type and capacity.
4. Determine How You Will Recharge Your 12V Off-Grid Power Supply
But before doing so, there is one more step you need to calculate, and that’s how will you recharge those A/Hs you drain from your batteries? Ideally you want to aim for a system that has a greater charging capacity than usage.
Our rule of thumb is that we only aim to discharge our system by approximately 30% of its capacity. This means we start the next day at 70% capacity. That way we have a greater supply than demand which allows us to be back to 100% capacity early the following day. As we use more power during the morning while recharging cameras, portable lighting and battery packs, this still leaves enough time in the afternoon to ensure we are back to 100% before the end of daylight hours.
5. Choose High-Quality 12 volt Power That Will Last The Journey
Due to the type of touring we like to do, we use a combination of different battery circuits that can be recharged via our alternator using BCDC chargers and solar power to replenish the daily amps drawn from using our appliances. We also add a three-day safety margin to cover for cloudy days when solar calculations would fall short.
Choosing the right charger for your dual battery system can be the difference to a seamless trip and finding that you have run out of power during a cloudy day or week. REDARC’s dual battery selector tool can help you determine your power requirements and some options that will suit your specific vehicle so you can build your own ultimate rig.
(Shaun Whale also has great advice on getting started with 12V power)
6. Monitor the State of Charge of your batteries (SOC) Of Your Batteries
This is a very important area because knowing how much charge you have left at any given time allows you to make adjustments in advance, well before it’s too late to be doing anything.
Relying on a 12v gauge to measure the voltage in your second battery will give you an indication, but only provides part of the answer. This is why having a gauge that calculates the amps being used and the amps being recharged back into your battery bank can give you a more accurate reading of the capacity remaining in your batteries.
The REDARC Battery Management System we have fitted to our set-up provides this information and more. Real-time information allows us to stop recharging our optional appliances such as camera batteries if we are down on overall capacity.
Our recent travels using the new set-up has returned outstanding results for us, with all of our 12v appliance needs being met whilst we are off grid. Our average SOC remained around 68% capacity and was replenished daily by midday, either by solar or our alternator BCDC combo.
Don’t Be Caught Without 12 Power Off-Grid Due To Overly Thrifty Calculations
The best tip we can give you is to take the time to work out your power load requirements. And when doing so, don’t be too thrifty in your calculations! The answers you get from this activity will put you in the best position to talk about battery capacity, and how you will recharge.
Safe and happy travels!
Grant & Linda
Looking to start your 4x4, camper trailer or caravan upgrade but not sure what products will allow you to travel the way you want? Take the REDARC Hilux product tour to find out what products are best for your power management and towing needs.
Frequently Asked Questions
Can I run a 12V fridge on solar?
Yes, you absolutely can, provided the sun is out! Generally, a 12-volt fridge will require 40-80 watts per hour, depending on its efficiency, insulation and size, as well as the temperature and where the fridge is kept. Plan for between 320 and 680 Wh per day, which can be delivered by a 100W solar panel in most Australian conditions.
How long will a 120Ah lithium battery run a 12V fridge?
This depends on the size of the fridge, however, most 12-volt fridges require 2-5 amps per hour. A fridge cycles on and off during the day and night, so effectively runs for about half of the time. If we assume the fridge uses 3A per hour and runs for 12 hours in a 24 hour period, it will use 36 Ah in 24 hours. If you want to keep your battery over 50% charged (less conservative than the example above) you can run the fridge for 40 hours before recharging the battery.
Will a 100W solar panel run a 12-volt fridge?
Yes, as long as the sun is shining you should be able to run a 12-volt fridge using a 100W solar panel. If you want to run other appliances at the same time, consider a larger solar panel or a battery to cover those cloudy days or twilight and overnight hours.
