15/10/2026
⚡ MY 48V OFF-GRID SYSTEM BUILD HAS OFFICIALLY STARTED! 🔋☀️
Why I’ve decided to go with a 48V system instead of a traditional 12V setup — and how it can actually save you money!
Today I’ve made a start on my new off-grid power system, which will eventually be used to help power my home and hopefully make a significant reduction in my electricity bills.
I’ve now mounted my Victron MultiPlus-II 48V inverter/charger on the wall, and my new WattCycle 51.2V 100Ah LiFePO4 battery is sitting in its new home, ready for the next stage of the installation.
The WattCycle battery has a capacity of 5,120Wh (5.12kWh) and features a 100A BMS.
I’m still waiting for several more components to arrive, which should hopefully be here next week. Once they arrive, I can continue putting the system together.
This is going to be a completely new video series on my YouTube channel, Phil’s Camping Review, where I’ll be showing the build, explaining the components I’ve chosen, and demonstrating why I believe 48V systems are becoming a very attractive alternative to traditional 12V setups.
And it’s not just about powering a home!
There’s a lot of useful information here for anyone building an electrical system in a caravan, motorhome, camper trailer or 4WD.
⚡ WHY 48V INSTEAD OF 12V?
For years, 12V has been the standard for most camping and caravan electrical installations.
And there’s absolutely nothing wrong with a properly designed 12V system.
I’ve been using them myself for many years.
However, the way we use electricity when camping has changed dramatically.
Years ago, most people were running a few LED lights, a fridge, perhaps a water pump and charging their phones.
Today, things are very different!
More and more people want to use appliances such as:
* ☕ Coffee machines
* 🍳 Induction cooktops
* 🍟 Air fryers
* 🍞 Toasters
* 🔥 Electric kettles
* 🍲 Microwaves
* 💻 Computers and other 240V appliances
These appliances can consume a considerable amount of power, especially when several are operating.
And this is where a 48V system starts to make a lot of sense.
🔌 LET’S TALK ABOUT CABLE COSTS!
One of the biggest advantages of using 48V is something that often gets overlooked.
The massive reduction in the amount of current flowing through your battery cables.
And that means you can often use substantially smaller cables.
Let me explain using the two diagrams I’ve attached.
For this example, we’re going to run a 2400W load through an inverter.
🔴 EXAMPLE 1 — THE 12V SYSTEM
To produce 2400W from a 12V battery system, the theoretical current required is:
2400W ÷ 12V = 200 AMPS!
That’s a substantial amount of current travelling between your battery and inverter.
And because we’re dealing with such high current, we need some serious battery cables.
In the example diagram, we’re using 70mm² copper cable.
Now, anyone who has worked with 70mm² battery cable knows exactly what I’m talking about!
It’s thick, heavy, expensive and not particularly easy to work with.
You also need suitable heavy-duty cable lugs, crimping equipment, fuses and connections.
And if your inverter is located some distance from your batteries, things become even more challenging.
The longer the cable, the greater the potential voltage drop.
That can mean having to increase your cable size even further.
🟢 EXAMPLE 2 — THE 48V SYSTEM
Now let’s look at exactly the same 2400W load, but this time using a 48V battery system.
2400W ÷ 48V = 50 AMPS!
That’s right!
We’ve reduced the current from 200A down to just 50A.
A massive 75% reduction in current for exactly the same power output!
And this is where things get interesting.
In the example diagram, we’re using 16mm² copper cable instead of 70mm².
Think about that for a moment.
We’re delivering the same amount of power, but the current is only one-quarter of what it was with the 12V system.
And we’re using a much smaller cable!
Now, 16mm² cable is considerably cheaper to purchase than 70mm² cable.
It’s also lighter, more flexible and much easier to route through an installation.
The cable lugs and associated connections are generally smaller and less expensive as well.
That’s a genuine opportunity to save money before we’ve even started talking about the other benefits of a 48V system.
One important point: the cable sizes in these diagrams are examples, not universal minimum requirements. Actual cable sizing must take into account inverter efficiency, maximum continuous and surge current, cable length, voltage drop, installation conditions, protective devices and manufacturer recommendations.
💰 THE SAVINGS CAN REALLY ADD UP!
Imagine you’re building a large electrical system in a caravan or motorhome.
Perhaps your batteries are installed several metres away from your inverter.
With a high-powered 12V inverter, you could be dealing with hundreds of amps.
That can require very substantial copper cables, particularly when you want to keep voltage drop under control.
Now compare that with a 48V installation delivering the same amount of power.
Because the current is so much lower, the cable requirements can be dramatically reduced.
And copper isn’t cheap!
On a larger installation, the savings on cable alone can be considerable.
Of course, the total system cost also depends on the batteries, inverter, chargers, protection equipment and any DC-to-DC converters needed for 12V accessories.
But the idea that a 48V system must automatically cost more than a 12V system simply isn’t true.
In some applications, particularly larger high-power installations, a properly designed 48V system can actually work out cheaper overall.
🔥 THERE’S ANOTHER BIG ADVANTAGE — LESS ENERGY LOST AS HEAT!
Whenever electricity flows through a cable, some energy is lost as heat because the cable has resistance.
The amount of power lost is related to the square of the current.
This is extremely important!
If we compare the same cable resistance at 200A and 50A:
At 200A, the resistive losses are much higher.
At 50A, the losses are only one-sixteenth as much.
That’s a theoretical 93.75% reduction in cable losses when the current is reduced to one-quarter, assuming the same cable resistance!
Of course, if you choose a smaller cable for the 48V system, its resistance will be higher, so the actual reduction in losses won’t necessarily be that large.
But it demonstrates one of the major advantages of using a higher system voltage.
We can design an installation with smaller cables while still maintaining acceptable voltage drop and efficiency.
And the bigger the system becomes, the more important these considerations can be.
🚐 WHAT DOES THIS MEAN FOR CARAVANS AND 4WDS?
I think this is where things are going to get particularly interesting over the next few years.
For people who only want to run a fridge, a few lights and charge some devices, a good 12V system is still an excellent option.
But if you’re building a serious off-grid electrical system and want to run high-powered 240V appliances regularly, I believe 48V deserves serious consideration.
You can still operate 12V equipment from a 48V battery system by using a properly sized DC-to-DC converter.
So going to 48V doesn’t necessarily mean giving up your existing 12V appliances.
It does mean the system needs to be designed correctly, with suitable components and protection.
And it’s worth remembering that 48V lithium battery systems operate above their nominal voltage when fully charged. They must be treated with respect, with properly rated DC equipment, isolation and overcurrent protection.
🔋 WHY I’M USING VICTRON AND WATTCYCLE
For this build, I’ve chosen a Victron MultiPlus-II 48V inverter/charger.
I’ve been using Victron equipment for many years and have had excellent results.
I particularly like the flexibility, monitoring capabilities and integration available with Victron equipment.
My battery is the new WattCycle 51.2V 100Ah LiFePO4, providing 5.12kWh of nominal storage capacity.
I’m impressed with what this battery offers, particularly considering its price.
But as with any new equipment, I’ll be putting it through its paces and showing how it performs as the project progresses.
One important part of this build will be ensuring the inverter settings, battery BMS limits and protective devices are all correctly matched.
The battery’s 100A BMS rating also needs to be considered when determining how much continuous power the system can safely deliver.
🏠 THE BIGGER PICTURE — REDUCING MY HOME ELECTRICITY BILL
My ultimate goal is to build an off-grid system that can supply a substantial portion of my household electricity requirements.
I want to take advantage of solar energy, store that energy in LiFePO4 batteries and use it when needed.
How much I eventually save will depend on the amount of solar energy I can generate, my household consumption and the final system configuration.
But I’m looking forward to finding out just how much of a difference this system can make.
And I’ll be sharing the results, including the successes, challenges and actual costs.
This isn’t going to be a series where I simply tell everyone that one system is better than another.
I want to demonstrate the differences with real equipment, real measurements and real-world results.
🎥 COMING SOON TO PHIL’S CAMPING REVIEW!
Over the coming weeks, I’ll be producing a series of videos covering this entire build.
We’ll look at the differences between 12V and 48V systems, battery technology, inverter selection, solar charging, cable sizing, installation costs, efficiency and much more.
I’ll also be looking at situations where a 12V system still makes better sense.
Because there’s no single electrical system that’s perfect for everyone.
But I do believe that as our demand for electricity continues to increase, particularly when camping and travelling, 48V systems are going to become increasingly popular.
And with the price of quality LiFePO4 batteries becoming more affordable, it’s now possible to build some very capable systems without spending the sort of money that would have been required only a few years ago.
The next batch of components should arrive next week, and then the build can continue!
For now, the Victron is mounted, the WattCycle battery is in position, and I’m looking forward to getting everything up and running.
All fixed 240V wiring and connections to my home’s electrical installation will need to be completed by an appropriately licensed electrician.
One final thought…
Before you spend thousands of dollars building a large 12V system to run high-powered appliances, take the time to investigate 48V.
You might be surprised at just how much money you can save on the installation, particularly when it comes to cabling.
And that’s just one of the many advantages I’ll be exploring!
What are your thoughts?
Are you still running a traditional 12V setup, or have you already made the move to 48V?
I’d be interested to hear what you’re using, especially if you’re running induction cooking, air fryers, coffee machines or other high-powered appliances when travelling.
Stay tuned!
Phil’s Camping Review 🔋☀️⚡
