Defender camper electrics

The electrical setup in our Land Rover Defender is comprehensive and tailored to our needs. Currently the entire system is based on the principle that we're self-reliant, but can enjoy most of the comforts we wish for.

It's a dual battery setup that can be charged by the alternator, shore power or the solar panel. It's a comprehensive and complete setup, except that we currently do not have a power inverter installed.

Below I'll explain what products are used and why I chose them.

Defender battery setup - storage

Running household appliances is great, but can only be reliably done when using a dual battery setup. Which means you'll have a starting battery for the vehicle itself and one or more household (leisure) batteries to run the appliances and charge your electronics.

For this we use two Optima Yellow Top 75AH batteries. They are certainly not cheap, but they're proven to withstand the elements and the non-stop abuse on the road.They can even be mounted on their side or upside down, no problem. These batteries are champions when it comes to deep-cycle power usage. At least if compared to a general lead acid battery. It's a true deep-cycle battery that can be discharged further than average, without affecting it's life cycle. These batteries are great, but you could also opt for lithium if you have the money.

To house them well we had to modify the battery compartment below the drivers seat. We extended the usable space by cutting out any folded edges and mounting a custom stainless steel box instead. As you'll see on the pics below it's still pretty hard to fit everything nice and neat in the battery compartment.

Land Rover Defender expedition camper with dual battery setup - Optima Yellow Top 75Ah

Don't mind the mess with all the cables running around. It's been cleaned up a bit since taking this picture.

Charging setup - three charging options

The batteries of the Defender are charged by the alternator, shore power on a campsite and solar power. This setup gives us plenty of options to keep the batteries and appliances fully charged.

Before we dive into the different charging options I want to briefly explain how the batteries are connected. For this we use the Victron Cyrix-CT relay. This small device will connect the batteries when the voltage is high enough, but keeps them disconnected when the voltage drops below a certain threshold. By using this relay we don't run the risk of draining the starting battery whilst running the fridge for example. Essentially the relay disconnects the batteries from each other when power is being used, and connects them when they're being charged.


The alternator is the most basic solution to charge the batteries. It will by default charge the starting battery, of course. But with our setup, thanks to the Cyrix-CT relay, it will also charge the household battery. During our wild camping adventures on the Europe Roadtrip we relied on this type of charging for 8,5 months. Big disadvantage is that you actually have to drive everyday to charge the batteries. Not that efficiënt when you're stationary on a wild camping location.

Shore power

For years our real bulk-way to charge everything, from the batteries to the appliances, was shore power. The power we get from power outlets around a campsite. In the customized battery-compartment we integrated a CEE connection, the universal outlet used around campsites in Europe. This shore power connection provides us with 230V, but not before running through a circuit breaker and 16amp fuse for safety. The setup is then connected to a multitude of 230V power outlets and extra USB ports. This way our CTEX MXS 5.0 battery charger will be activated, charging the household battery (and starter battery with the Cyrix-CT). It will also motivate the fridge to switch from 12V (battery) to 230V (shore power).

Defender overland camper with shore power camping power outlet

Solar power

The most recent addition (April 2020) is the solar charging setup. This will provide us with ample amounts of power to run our appliances and charge our gear. It lets us live off the grid for way longer, it gives us freedom and peace of mind. The setup consists of the Top Solar 110Wp Mono solar panel and the Victron MPPT 75/15 Bluetooth charge controller. The panel is normally used on campers/RVs and is of great quality, although it's not a light weight version. The charge controller has build in Bluetooth which is perfect for keeping an eye on the solar output and adjusting the settings of the charge controller.

The solar panel is mounted on brackets that can be set to the desired angle. Currently it's set to catch the most sun and act as a wind deflector for the aluminium boxes. But it's also possible to put it flat on the roof rack. The cable connection is wired through a protective cover and then run along the snorkel. It then enters the engine compartment and runs along the bulkhead, down towards the battery box, where it connects to the charge controller.

Land Rover Defender camper with a solar panel on a bracket on the roofrack

Camper appliances - consumers

The above three options give us enough freedom to explore the world. We like to live off the grid and travel to remote places, without visiting too many campsites if possible. Below you'll find our power consuming appliances. Important note is that we don't have a power inverter yet, so no 230V power outlets are active without shore power. All of our gear can be charged through the 12V cigarette lighter outlets and the 5V USB ports.

On an average day you won't find us on a campsite, which means we're reliant on the alternator and the solar panel to charge our batteries and appliances. This will let us use the 12V cigarette lighter outlets and the USB ports. We use them to charge our phones, laptops, camera gear and chargeable batteries for the flashlights and small fan. The Indel B Travel Box 51 compressor fridge will run directly of the battery.

Once shore power is connected both batteries will be charged and additional 230V power outlets and USB ports will become active. The fridge will automatically switch to the 230V power outlet instead of using the battery. This is a build in feature of the fridge. The shore power will also let us use the build-in floor heating, which we've actually never used. We live outside, or take shelter under our awning or in our rooftent.

To prevent the batteries from draining too much it's necessary to monitor the voltage once in a while. Especially when the sun isn't shining. To do this we use the simple but effective Voltronic voltage meter, which provides us with a reading for the household and starter battery.

Defender camper interior with electrical appliances

Electrical setup details

Defender camper power overview

Defender camper electric overview blueprint