Our campervan power setup, explained

The system at a glance

Every van power system does the same four jobs: bringing energy in, charging the batteries safely, storing it and sending it to the things you use. Here's how that works in Ron, our 2018 Renault Master.

Ron has 240V throughout, so a movie night or a cup of tea at the push of a button is easy, even off-grid.

A simplified picture of our van, not a wiring diagram.

Not electrical advice. This is how our van is set up, explained in plain English. Our refit was done by an auto electrician, and the 240V side has a certificate of compliance. If you're planning or changing a system, please use a qualified auto electrician.

What each part does

Batteries: where the energy is stored

When we had the electrics refitted, the old battery came out and two Amptron BluEdge ABS 200Ah lithium batteries went in, giving us 400Ah at 12V. They sit in a purpose-built battery enclosure with a drop vent. We check them over Bluetooth and on our Renogy 500A Battery Monitor in the van.

DC-DC charger: solar and driving

A DC-DC charger takes power from the vehicle's alternator and charges the leisure batteries correctly, without the starter battery and leisure batteries simply being joined together. Ours, the REDARC BCDC1240D, also takes the power from our two 120W roof panels, so one unit handles both.

As part of the refit, the electrician set it to a lithium charging profile, upgraded its input cable to 6 B&S, protected it with a midi fuse and added an ignition wire, so the charger knows when the engine is running.

Mains charger: powered sites

When we're plugged in at a powered site, the Victron Blue Smart IP22 12/30 charges the batteries from mains. It has its own socket, protected by its own RCBO, and that socket only works on mains power. That way the inverter never ends up trying to charge the batteries from the batteries.

How the 240V side works

The Victron Phoenix Smart Inverter 12/3000 turns the batteries' 12V into 240V, so we can use normal appliances off-grid.

A Hager 25A changeover switch sits between the inverter, the van's mains input and the 240V system. Ours is manual: we flick it by hand to choose mains, when we're plugged in, or the inverter, when we're not. The sockets are fed from one or the other, never both at once.

From there, the 240V circuits are protected by double-pole RCBOs. That's a circuit breaker and an earth-leakage (RCD) safety switch in one, and the van has a 16A one and a 10A one in a small RCD enclosure. The sockets are double-pole GPOs, which switch both wires rather than just one. One of them has USB outlets built in.

Fuses and protection

A lithium bank can deliver a lot of current very quickly, so good fusing and the right cable size matter as much as the components. In our van:

• Heavy 00 B&S cable for the high-current connections, protected by a Mega fuse.
• Midi fuses on the smaller runs, including the DC-DC charger's supply.
• Fuses added to 12V cables that didn't have them. This was found and fixed during the refit.
• The van's existing 12V fuse board, which was already in the van, still distributes the 12V circuits: the fridge, water pump, lights, some USB sockets, the electric awning and a 12V TV power socket.

How we make the power last

• Inverter off when it's not needed. We switch it off from our phones whenever we drive, and turn it on when we need 240V.
• Small loads go to the power station. We often run our laptops from the ALLPOWERS power station instead of turning the inverter on.
• Run the fridge on one side. Our Dometic CFX3 95DZ has two zones that run on their own. We use one side as a fridge and the other for dry storage.
• Save heavy cooking for mains. The Dune induction hob is our go-to when we're plugged in. Off-grid, we switch to the Lido gas cooker.
• Air-con on mains only. We try to run the KickAss 400W air conditioner only when we're plugged in. Most warm nights, the Sirocco II and MaxxAir fans are enough.
• Keep an eye on the numbers. We check the batteries over Bluetooth and on our Renogy battery monitor, so there are no surprises.
• Do you need a TV aerial? We have a Winegard TV aerial on the roof, but with our smart monitor and the power setup, we just don't need to use it.

See the fridge, cooking and cooling gear · See the roof

Our portable power: ALLPOWERS

Separate from the van's own system, we have a portable power station and a foldable solar panel. They give us power outside under the awning, and another way to stay off-grid for longer.

What we'd tell anyone planning a setup

• Start with what you'll run. Appliances like a coffee machine draw a lot of power, so you'll need a decent inverter. Ours is 3000W, and it runs the Bambino, the oven and the hob with no issues.
• Check every charger's profile. When we went lithium, our DC-DC charger had to be switched to a lithium profile.
• Plan for more solar than you think. More solar is the one thing we'd change about Ron.
• Get the 240V side certified. Ours has a certificate of compliance. Ask for one if your van has 240V.
• Use a qualified auto electrician. We left the electrics to the professionals, and we'd recommend you do the same.

Want to see the van in more detail?

An updated van tour is coming soon.

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