A basic guide for understanding RV power sources

Learn about RV power, recharging, solar panels, and generators. Enhance your travels with expert tips.

When it comes to choosing a suitable power supply for your RV, there are plenty of options available — just make sure you consider the types of trips you want to take before making your choice.

Many underestimate the importance of power supply when choosing a motorhome, but not being able to power all the essential gadgets we can have come to rely on in our modern world can make or break a holiday. There are several separate and related power sources you may need to consider when setting up your rig, potentially making it one of the most complicated parts of motorhome life.

Most of your RV’s appliances (lights, TV, etc.) will run on either (or both) 240V mains power or 12V battery power. Others such as your cooktop or perhaps a water heater will probably require gas, while a generator or space heater may use diesel.

To make your RV travelling experience as enjoyable as possible, all these power sources need to be understood and considered. Without understanding all the available options to you, you may make a misguided and regrettable decision when choosing a power system for your pride and joy.

While there are many variables to consider when it comes to power supply, above all it’s a good idea to learn when and where you can access 240V power if needed, how you’ll power your 12V batteries and where and how you will source and carry your additional fuels of gas or diesel.

POWER SOURCES

240 volt

No matter what sort of RV you have (entry-level, offroader or top-of-the-line, etc.), it will be built to operate on 240V mains power. This is the same power your house runs on and the same power available in caravan parks.

When you’re hooked up to mains power, you won’t be depleting your on-board power source (12V battery power) and can run any appliances within your RV — even high-draw items such as coffee machines or hairdryers — without issue.

12 volt

When heading out to remote locations without caravan parks and mains power, you’ll need to rely on your 12V battery setup. This will differ between RVs and the options chosen at purchase or build. Different travellers have different needs, and these can vary wildly, making your battery choice a personal one.

Batteries are power storage devices which, when correctly charged (more on this below), can power a range of modern small appliances for limited periods — including items such as lights, TVs and radios but excluding high-draw items such as kettles and toasters.

It goes without saying that once the appliances have used up all the stored power within the batteries, they’re due for a recharge.

Gas

Despite the recent introduction of gas-free motorhomes, and their growing popularity, most modern RVs use at least one (if not more) gas appliances. These include internal gas cooktops, external gas barbecues and even gas space heaters.

If your rig has gas appliances, you’ll need to carry one or more gas cylinders with you — depending on your needs. These are the same cylinders you would use for your barbecue at home, so they’re easily swapped or refilled when required.

Diesel

Diesel appliances are less common than gas, however, you may choose to run a diesel generator to supplement your power sources, or even a diesel space heater to keep your RV warm.

If your rig has diesel appliances, you’ll need to source and carry diesel on your trips. Diesel is usually carried in dedicated jerry cans on the outside of the vehicle.

Petrol

If your tow vehicle’s engine runs on unleaded petrol, you will need to consider your fuel requirements during every trip. If you don’t have a long-range fuel tank or you’re doing long stretches in remote areas, you’ll need to carry fuel with you to ensure you don’t run out and become stranded.

RECHARGING

The central element of any RV power system is the battery and all other energy management equipment — such as solar panels or battery chargers — should work closely with the battery. Finding effective and efficient ways to charge your motorhome’s 12V batteries is vital … read on for our tips.

Battery charger

The most obvious method to charge your 12V batteries is a battery charger. A charger basically reverses the chemical reaction that takes place within a battery when an appliance is drawing power from it — which charges it instead of depleting it.

You must remember that most chargers require 240V mains power to work and so are not very useful is travelling away from civilisation for long periods.

Solar panels

Solar panels work by converting available sunlight to electrical energy, which is then managed by a solar regulator and stored in a deep cycle battery. 12V DC electrical appliances can be run from the battery while an inverter will be needed to power 240V AC appliances.

Using solar energy to recharge your 12V batteries while away from home is a popular option as solar power creates no noise, no fumes, is environmentally sustainable and comes with basically no costs after you pay for the initial setup.

A well-managed solar system is more than enough to power most standard 12V usage, however, and this is an important aspect to consider, the efficiency of your panels is reliant on weather and often the position of your motorhome (for roof-mounted panels). This means you need to be parked in direct sunlight to take advantage of the sun’s free power, which may or may not be where you actually want to camp for the night.

Vehicle alternator

RV batteries (12V) can be set up to charge from the vehicle’s alternator while underway. Unfortunately, in some cases due to the length of the cable required for this setup, voltage drop can be an issue. The method is therefore not 100 per cent reliable, however, there are after-market devices — such as boosters — available which minimise voltage drop.

Generators

A portable generator creates electricity from a gas-powered engine which turns an on-board alternator to generate electrical power. Power outlets on the unit work just like the power points in your home, so there aren’t many limits to what you can run using your generator.

Despite being noisy and expensive, generators are a reliable way to get your power needs met. Due to them being so noisy and expensive, they are generally considered a last-resort option, but they can certainly be a useful addition to any power setup.

The cost of a generator depends largely on its size and unlike solar panels, generators require ongoing costs to run after the initial purchase. These ongoing costs include fuel and servicing.

It’s also important to note that generators are now banned in many national parks and campsites due to their impact on other campers.

QUICK TIP: Always be mindful of the availability of charge. In the same way that you keep note of distances between petrol stations, pay attention to how far the next 240V mains power is or whether the sunshine will be sufficient on cloudy days.