Motorhome off-grid installations

What does going off grid really mean?

For some people, going off grid simply means spending a night away from an electric hook-up. For others, it means having the freedom to spend several days — or even longer — in a favourite location without needing to plug into mains electricity.

There isn't one off-grid system that suits every motorhome, campervan or leisure vehicle. Every MACSUK installation is tailored to each individual customer. The right solution depends on how you travel, how much power you use, the space and payload available in your vehicle, and your budget.

That is why, before talking about batteries, solar panels or inverters, it is worth thinking about what you actually want your vehicle to be able to do.

How do you want to travel?

Start by thinking about a typical trip.

Are you mainly staying on campsites, but would like enough battery capacity for the occasional night without hook-up? Perhaps you regularly use aires, rallies, festivals or simple stopovers and would like to comfortably manage two or three days independently.

Or perhaps your aim is genuine long-term off-grid touring, where you want to use many of the same electrical appliances you would use at home while relying as little as possible on campsites and mains electricity.

These are very different requirements — and consequently need very different systems.

The more time you want to spend away from hook-up, and the more electrical equipment you want to use while doing it, the greater the demands placed on your electrical installation.

It's not just about how long you stay off grid

One of the biggest factors is what devices you want to power.

Lighting, phone charging and a television place relatively modest demands on a leisure battery. Start adding high-powered appliances and the picture changes considerably.

An induction hob or air conditioning unit, for example, can require around 1,500–2,000 watts or more while in use. A hairdryer might use a similar amount. Microwave ovens, combination ovens, coffee machines, kettles and air fryers can all be significant consumers of electricity.

Even appliances that use less power at any particular moment can become important if they run for long periods. A compressor fridge is a good example: its instantaneous demand may be relatively small, but it operates throughout the day and night.

So, there are really two questions to consider:

How much power do you need at any one time, and how much energy will you consume in total over an entire day?

Understanding both is an important part of designing an effective off-grid system.

Where does all that energy come from?

Think of an off-grid electrical installation as having three basic jobs: storing energy, replenishing that energy and delivering it in the form your appliances need.

Batteries — storing your energy

Your leisure batteries are effectively your vehicle's energy store.

Increasing battery capacity allows you to store more usable energy and potentially remain away from hook-up for longer. Modern lithium batteries can provide considerably more usable capacity than many traditional lead-acid installations and can also cope with high electrical loads.

But simply fitting a bigger battery isn't necessarily the answer.

Once you use the energy stored in that battery, you need a way of putting energy back into it.

Solar — harvesting energy from daylight

Solar panels can replenish your batteries whenever suitable daylight is available.

For many travellers, solar is an important part of an off-grid system because it can replace some or potentially all of the energy consumed during the day and the night-time periods.

However, solar generation isn't constant. The amount of energy available varies according to the size of the solar array, time of year, time of day, weather conditions, location and even where the vehicle is parked.

A system designed around summer touring in southern Europe may therefore have very different requirements from one intended for year-round use in the UK.

Battery-to-battery charging — generating energy while you drive

A battery-to-battery, or B2B, charger uses energy produced while the vehicle is running to recharge the leisure batteries.

For people who move regularly, this can be a particularly useful source of energy. If you tend to drive every day or two, your requirements can be quite different from somebody who parks in one location for a week.

Again, your travelling style matters.

Inverters — providing mains-style power

Your batteries store DC electricity, while many familiar household appliances are designed to run from 230 V AC mains electricity.

An inverter converts the battery's DC power into 230 V AC, allowing suitable mains appliances to operate when the vehicle isn't connected to electric hook-up.

The size of inverter required depends on what you intend to run. Powering a laptop charger is very different from running an induction hob, microwave or hairdryer.

As inverter size and appliance loads increase, the batteries, cabling, protection equipment and charging system all need to be capable of safely supporting that demand.

This is where off-grid installations become more complex

Imagine that your requirement is simply to spend an occasional night away from hook-up while running lights, water pumps, phone chargers and a television. The solution may be relatively straightforward.

Now imagine that you want to spend several days off grid while using a compressor fridge, induction cooking, microwave, coffee machine, hairdryer and other mains appliances such as air-fryer or air-conditioning.

Suddenly, the system has a much bigger job to do.

You may need greater lithium battery capacity, more solar generation, higher charging rates while driving, a more powerful inverter, heavier cabling, additional protection and control equipment, and potentially changes to the vehicle's existing electrical installation.

All of that equipment also has to go somewhere. The engineers at MACSUK specialise in optimising the available space and refabricating the structure of your habitation area to facilitate the housing of the equipment required for each bespoke installation. Our aim is to return every vehicle to the customer with all of the necessary components integrated so as they appear as if they had been installed from new.

Space, weight and budget matter

Battery capacity and charging capability cannot simply be increased indefinitely.

Every vehicle has physical limitations. Batteries, inverters, chargers and associated equipment require installation space. Solar panels need suitable roof area. Larger electrical systems require appropriately sized cabling and protection. Additional equipment also adds weight, which has to be considered alongside the vehicle's available payload.

Then is the budget.

At 2026/7 prices, it would be reasonable to expect to pay at least £4-5k for a basic system upgrade that is capable of enabling comfortable off-grid living for a long weekend without inverted power. If your ambition is to achieve a completely self sustainable off grid lifestyle (sensible usage applies!) to include 240 and greater power generation/capacity, then it would be wise to expect an estimate in excess of £8.5k to create a professional, safe and fully integrated Victron based system.

A system intended to provide basic independence for occasional overnight stops will naturally be very different from a comprehensive installation designed to support prolonged off-grid touring and high-powered 230 V appliances.

That doesn't mean one solution is better than another. Our aim is to create a system that is appropriate for you and the way you actually use your vehicle.

Designing your off-grid solution

When you talk to MACSUK about an off-grid installation, some of the most useful information you can provide isn't technical at all.

Think about where you travel, how frequently you move, how long you would ideally like to remain without hook-up and what electrical appliances you consider essential.

Also consider the equipment you already have and any items you may wish to install in the future, not just within this project, but a year or more down the line. What batteries are fitted? Do you already have solar? What charging system does the vehicle use? And, importantly, how much space and payload are available for upgrades?

From there, the different elements can be considered together — battery storage, solar generation, charging while driving, inverter capacity, mains charging, monitoring, cabling and electrical protection — rather than treating each component as an isolated upgrade. Carrying out electrical upgrades to your vehicle requires a ‘whole system approach’, where the interdependencies of equipment and lifestyle are considered together.

From one night to genuine off-grid independence

There is a natural progression with off-grid electrical systems.

The occasional night away from hook-up may require relatively little additional equipment. Staying away for several days requires more stored energy and better ways of replenishing it. Using high-powered mains appliances increases the demands again. Extended off-grid living throughout different seasons can require a carefully balanced combination of substantial energy storage and multiple charging sources.

That is why the starting point shouldn't be:

“How big a battery can I fit?”

A much better question is:

“What kind of life do I want to live in my motorhome, van or caravan?”