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DIY Camper Van Electrical System: Wiring and Power Management

For most DIY lovers who’ve chosen a do-it-yourself campervan conversion, installing the electrical system is the most daunting part. An avidly done DIY camper van electrical system means you’ll have an efficient power supply and enjoy your adventure.

In this simple guide, we’ll explain the fundamentals of wiring and power management in your campervan. Without much ado, let’s dive right into it.

The Basic Elements of a Campervan Electrical System

Before getting started, it’s crucial to understand how a van’s electrical system works. At a basic level, the electrical system is responsible for harvesting and storing energy that you’ll use while on the road. The system comprises three core elements: a charge source, batteries, and an electrical load.

Charge Source

Campervans can spend hours or even days out in the wild, so the charge source ought to be as efficient as possible to meet this requirement. The charge sources commonly used in campervans are solar panels, alternators, and shore power. The best DIY camper vans have powerful solar panel systems for harvesting power even during cloudy days.

If your solar system has an output larger than 300W, go for bigger residential panels. You can opt for multiples of 175W or 200W panels. With a bigger panel, the mounting and wiring are simplified.

Solar panels often make the primary source of power for campervans. But it doesn’t hurt to have a backup, especially when navigating through remote areas with inadequate sunshine. The most ideal choice is a DC-to-DC charger.

Sizing your solar charge controller

It’s often known as the maximum power point tracking solar charge controller (MPPT). The MPPT is responsible for converting the solar energy voltage for harvesting at an optimal voltage safe for charging the batteries. It offers more efficiency than other solar charge controllers due to a higher power output to battery ratio.

Sizing your solar charge controller

MPPT charge controllers come with a ratio, say 100/30, which is the maximum voltage against the maximum current they can output. To find out the safe rating for your system, you’ll need to determine the number of solar panels used and how they’re wired. If you wire the panels in parallel, sum up the amperage rating of each panel. For series panel connection, sum the individual voltage ratings of each panel.

The result should not be greater than the maximum voltage and current of your charge controller.


A DIY camper van electrical system relies on a battery bank for power storage. The bank may have a single or multiple batteries. An important point to note is that your camper van’s battery should always be different from the starter battery. The additional battery bank is sometimes known as a leisure battery or auxiliary battery.

Campervans use four battery types; flooded lead-acid (FLA), lithium-ion (LiFePO4), absorbent glass mat (AGM), and gel cell.  Li-ion and AGM batteries are the only ones that provide a realistic source of power that suits campervans. An ideal battery rating for this application is a 12V 100Ah or 200Ah.

To determine the number of batteries needed, you have to calculate how much power the campervan will use in 24 hours. The higher your load is, the more batteries you’ll need. A standard campervan electrical system has a 400-600 Ah power requirement. This is enough for charging devices, basic lighting, and ventilation.

But if planning to run high-energy consuming appliances such as a refrigerator or air conditioner, your electrical system will need more than 600Ah.

Choosing an inverter

A typical battery offers 12V, which is not sufficient to power appliances. So, an inverter pumps up the voltage to 120V, suitable for your campervan use. If you’ll be using shore power to charge your batteries, it’s ideal to equip your campervan with an inverter charger.

Choosing an inverter

To determine the size of your inverter, you’ll need to conduct an AC power audit. This will reveal how much current the appliances will draw from your DIY campervan electrical system. After finding out your AC power requirements, go for an inverter with a slightly higher rating. For instance, if you’ll be using an induction stove top that draws 1900W for cooking, you can opt for 3000W. This gives you a wider room to run another appliance such as a blender while cooking.

Battery Monitor

You wouldn’t want a surprise power outage caused by lower batteries while in the middle of nowhere. That’s why a battery monitor makes a great inclusion in your van electrical system.  The gadget is particularly handy during the initial weeks of using your campervan as you establish your power consumption needs.

Go for a smart shunt with Bluetooth that can convey the readings to your phone. Alternatively, a monitor with a digital display can be handy.

The Load

The load comprises any electronic or electrical equipment that discharges your campervan leisure battery. These include but are not limited to kitchen appliances, ventilation fans, LED lights, refrigerators, internet hotspots, and phone chargers.

To reduce the electrical load on your campervan electrical system, you might want to consider using separate solar-powered devices. For instance, you could opt for solar LED lamps, solar-powered phone battery banks, et cetera. This will leave your leisure battery with more energy to power heavy consumers such as refrigerators.

Choosing a Lynx distributor or bus bar

A typical DIY campervan electrical system has several cables emanating from the battery terminals. This requires a way to extend the negative and positive terminals so your setup is clean and easy to manage. The right solution for this is using a bus bar. Alternatively, a Lynx Distributor, which is a +/- bus bar, can be a better option.

Lynx Distributors or bus bars prevent stacking up your battery terminals with lugs. They present a cleaner electrical system, which makes the management aspect much easier.

DC Fuse Panel and AC Distribution Panel

DC Fuse Panel and AC Distribution Panel

All DC appliances in your campervan use the DC fuse panel as a distribution point. The LED lights, roof fans, USB plugs, refrigerator, and heater are hard-wired into the DC fuse panel, which should have the right fuse size to protect the equipment.

An AC distribution panel allows each AC equipment on the van electrical system to have its separate circuit breaker. Power is distributed from the inverter into the distribution panel and then to the AC outlets. A 15A circuit breaker used in household outlets is ideal for your campervan AC needs. If you have high-wattage applications like water heaters, power tools, or induction cooktops, you may opt for 20A circuit breakers.

Master Switch

The AC outlets are under circuit breakers while the DC outlets are controlled by fuses. This makes it easy to individually control every outlet as needed. But that doesn’t mean power isn’t flowing through the whole electrical system. A master on-off switch allows you to turn the power on and off through the entire system when desired.

Wiring A Campervan Electrical System

Now that we’ve discussed the fundamentals of a DIY campervan electrical system, it’s time to look at the key wiring requirements:

12V Vs 24V Electrical System: Which One Should You Pick?

A typical DIY campervan electrical system is 12V rated. But that doesn’t mean there are no 24V systems. A system that has power requirements lower than 7kWh should use 12V batteries. That’s because they are readily available and come with plenty of manufacturer options. Plus, you won’t need to do modifications to suit your DC appliances.

Opt for 24V batteries if your van electrical system is larger than 7kWh. In that case, you’ll need to dig a little deeper into your pockets to get the batteries. Plus, the wiring process is much more complicated, but the system will be compact to handle any requirement.

Picking The Right Wire Gauge

Picking The Right Wire Gauge

Choosing the wire gauge isn’t difficult as you only need to consider your electrical system load and the distance between the power source and the appliance. It’s generally safer to pick a wire with a larger gauge, but the converse can be catastrophic. But the only disadvantage of a large wire gauge is that it’s expensive to obtain and can be a bit difficult to work with.

Due to the constant vibrations your campervan will be subjected to, you’ll a stranded copper wire as opposed to solid wire used for residential wiring. But you can still use a solid copper wire, only that it’s highly not recommended.

1.  Determine the current amperage

Appliances usually have their power ratings written on their labels or listed in the specifications sheet. However, most are in Watts (W) instead of Amperes (A), but that shouldn’t be an issue as you can convert them with ease: divide the power (W) by voltage (V).

2.  Find the length of the circuit

This is simply the length of the wire, from the power source (battery) to the appliance (power outlet), and back to the batteries. Remember to round off the length to a higher value.

3.  Is your appliance a “critical voltage drop” type?

The existing resistance in the wire as power travels from the source to the appliance often causes a voltage drop. That means that the voltage from the source won’t be the same as the one being utilized by the appliance. Some equipment can tolerate huge voltage drops while others can’t. The critical voltage drop types can only withstand a 3% drop, while the non-critical type can tolerate up to 10% drop.

When determining the voltage drop, consider the wires connecting your batteries, inverters, DC fuse panels, MPPT charge controllers, etc. These make up the critical voltage drop wires. On the contrary, non-critical voltage drop wires comprise those at the point of use. They offer a higher tolerance to fluctuations, but be sure to confirm with the appliance manufacturer beforehand.

Fuses, Wire Sheaths, and Wire Conduits

Your DIY campervan electrical system must also have protection from all sorts of electrical dangers. The most common hazard is the rubbing of wires against the insulation, which then introduces conductance with the vehicle’s body. Also, the fact the wires are routed through squeezed spaces increases the risk of coming into contact with other hazards. This combined with frequent shaking while moving increases risks.

Fuses protect a circuit when an overcurrent occurs. It’s basically a thin wire that melts when the current flowing through it exceeds its capacity. To pick the right fuse, check the appliances on your van electrical system. The minimum size of the fuse should be equal to the appliance’s current rating multiplied by 1.25.

Wire sheath offers an additional layer of protection against the rubbing of wires. It’s ideal for covering wires when passing through wall cavities with sharp edges. Also, ensure the wires pass through a conduit for protection should the rubbing action of the wire cut through the wire sheath.

Installing The Van Electrical System

At this level, we’ve covered pretty much every fundamental detail that your campervan electrical system should have. All you need is the right campervan electrical system kit to kick off the installation. Here’s a simple step-by-step process for installing the electrical system:

  1. Following a logical electrical plan, mount all the necessary electrical components in their respective position. Pay attention to the need to pass wires through.
  2. Position the batteries in the desired setup and wire them as appropriate following the series or parallel arrangement.
  3. Supply power from the batteries to the bus bar or a Larynx Distributor. Also, ensure the connectivity delivers electrical power to your battery monitor, main switch, and battery fuse.
  4. Ensure power goes to the DC-DC charger, MPPT solar controller, and inverter connected to the bus bar.
  5. Wire the AC outlets and DC appliances, ensuring the wires are protected through a sheath and a conduit.
  6. Check the entire electrical system to ensure all connections are done properly. Test the system to complete the installation.


A DIY campervan electrical system is the most daunting aspect of doing a campervan conversion. Besides requiring some upfront knowledge about electrical wiring, you need to research the necessary electrical components before installation. this will ensure that your electrical system will be able to support your energy requirements when you’re out pursuing your outdoor adventure. If the entire process seems too challenging, find an expert to do the electrical system installation for you.

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