Want to charge a laptop or blend a smoothie in your campervan? 😋 Well, you're going to need some plug sockets! To install plug sockets in a van conversion we need a 12v to 240v inverter. In this article we will learn all about campervan inverters, how to size them, the best brands, and how to install one. By the end, a large part of your van electrical system will be complete! I'm Shane, I've been teaching people to convert campervans for many years, I'm the author of The Van Conversion Newsletter, the van conversion instructor at Udemy, and the proud owner of a beautiful self-build campervan called Beans. So let's jump in to this complete guide to the campervan inverter!
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These are the best 12v to 240v inverters for you van conversion
How to install a pure sine wave inverter inverter in your campervan
Note: Did you know that you can get a free electrical wiring diagram by signing up to The Van Conversion Newsletter 🙂
Supplies List 🛒
To wire up plug outlets in your van; an outlet is connected to the inverter with a plug head
What is a campervan inverter and why do we need one?
A campervan inverter is a device that converts Direct Current (DC) electricity into Alternating Current (AC) electricity. In relation to a van conversion, it converts the 12v electricity from our leisure batteries into 110/240v electricity - a 12v to 240v inverter.
You will need a campervan inverter if you want to run any AC appliances (eg. charging a laptop through a plug socket) .
Alternating current (AC) vs. Direct current (DC)
Let's have a quick refresher. There are two kinds of electric current: direct current (DC) and alternating current (AC). Electrons move in one direction with direct current (batteries produce direct current). Whereas in alternating current, electrons flow in both directions.
Direct current electricity flows in one direction: out the Positive (+) side of the battery, to the appliance, and back into the Negative (-) side of battery. In a DC system, positive wire is typically coloured red, negative wire is typically coloured black. Car batteries are DC, typically 12v (12 volt).
We can think of this movement of electricity like a river; it only flows in one direction.
Many van conversion electrical appliances will be 12v DC, such as the fan, heater, or lights.
With alternating current, the electrical force vibrates rather than flows. This is known as oscillation. In an AC system there is no positive or negative, current is instead transmitted through these vibrations. We can think of this like waves across an ocean: force moves, but the water does not.
AC electricity does not just flow in one direction, indeed it periodically reverses direction.
Mains electricity is AC, ie. the electricity you use in your house. In North America 110v is typically used for AC, whereas in Europe 230v is used.
An AC household appliance (eg. a kettle) will have 3 wires running to it: Live (blue), Neutral (brown), and Ground (green & yellow).
When converting a van, you will likely want plug sockets (so you can charge your laptop to watch netflix...). These plug sockets are AC.
If you want to learn more about electricity as it relates to van conversions, you can read more here. The article covers volts, amps, watts, batteries, solar, AC, DC, and more.
Pure sine wave inverter
Pure sine wave inverters give off much cleaner electricity as opposed to modified sine wave inverters. In a pure sine wave inverter, the AC power produced by the campervan inverter closely matches the actual sine wave; it is smooth as opposed to stepped.
This is especially important for very sensitive devices that we really don't want to break. Like our laptop.
Always choose a pure sine wave inverter.
How to size the 12v to 240v inverter for you van conversion
Sizing your 12v to 240v inverter is very simple. You just need to figure out the total wattage you expect to use at any given time.
For instance, if you might be charging a 90w laptop, while also using a 650w blender and a 170w electric blanket. This means your inverter must be able to handle 870W at a minimum. We will want to give ourselves a ~15% safety buffer on top of this, so we will probably go with a 1000W pure sine wave inverter.
We should try and size our campervan inverter as closely as possible to what we actually expect to use. If we get an inverter that's way too big, we will lose a lot of efficiency in terms of energy usage versus having a smaller one.
Tips when using your campervan inverter
Make sure you turn off your inverter when you're not using it! Campervan inverters (especially cheap ones) passively suck energy from the batteries. Believe it or not, they can use up to 5a of power just being on.
Try to wire as many appliances as you can directly into your 12V DC system. When running appliances through a camper van inverter, you lose about 15% efficiency in the conversion of DC into AC. For instance, we should charge our phones through USB cigarette lighter chargers, rather than through the plug sockets.
These are the best 12v to 240v inverters for your van conversion
The Budget Option
You can easily pick up a 12v to 240v inverter like this on amazon that will do the trick in a snap. These type of camper van inverters won't be as durable or efficient as their more expensive brethren, but they are a good budget option!
Top Pick: Renogy Pure sine wave inverter
Buying a pure sine wave inverter from a trusted brand like Victron or Renogy will be your best option long term. The product will last longer and is more energy efficient. Renogy make excellent inverters, and many van conversions are fitted with their 2000w pure sine wave inverter. It is a great choice.
I regret not buying this inverter the first time round as my cheaper campervan inverter brought me a lot of headache over the years.
If you are planning on also installing shore power in your van conversion (ie. charge your batteries by plugging into mains at a campsite), you should definitely check out an inverter / battery charger combo like this one. Yep... one device with double functionality. Save space and money!
Solar Inverter Charger
If you thought double functionality was nifty, how about triple functionality? The Renogy solar inverter charger combines:
80a Solar charge controller
3500w pure sine wave inverter
120a Battery charger
It also comes with mobile connectivity to monitor your device/batteries. One thing to note is that this only works with 48v leisure batteries (which are pretty rare on their own). So what this means is that you will likely need to wire four 12v batteries in parallel. Certainly doable, but perhaps it's own mission. Still... I'm drooling at this device.
How to install a pure sine wave inverter in your van conversion
Note: You can get a complete wiring diagram when you sign up to The Van Conversion Newsletter. The diagram shows you how to wire up your batteries, your campervan inverter, your solar, and everything else! I send out the wiring diagram straight away when you sign up. If you want a full overview of the electrical system, you can check out this guide.
Connect the camper van inverter to the bus bars
The camper van inverter has a positive and negative terminal on it. Wire the positive terminal to the positive bus bar and the negative terminal to the negative bus bar. I used 2AWG cable for this, but you should do your own calculations for the wire size you need. You can learn all about wire sizing here. Remember, the bus bars are directly attached to the leisure batteries.
On the positive wire, we will connect a ~175a mega fuse (for a 1000w inverter) as close to the bus bar as possible; this protects the inverter (and wire) in case of a huge surge in electricity. Most 1000w pure sine wave inverters will allows for a surge/peak of 2000w for a short period of time. 2000w equates to 166a in a 12v system (2000w / 12v = 166a). So our fuse should not blow at 166a, but instead be a little bigger, hence why we use a 175a fuse for a 1000w camper van inverter. You can learn about fuse sizing here.
Add a terminal switch
On the positive wire we also want to install a terminal switch. This is a big switch that allows us to easily turn off our 12v to 240v inverter. Remember: we should turn off our inverter whenever we are not using it to save electricity.
You will also want to ground your campervan inverter; you can do this by grounding it directly to the vehicle chassis or by vicariously to the vehicle chassis through the negative bus bar. You can learn all about ground for van conversions in this article.
How to wire up plug sockets in your van conversion
First, grab some three core cable and wire up a plug head! Here's what that looks like for a UK plug:
Remember, 3-core cable is insulated AC cable with live, neutral, and earth wires.
Pop the plug head into the front of your campervan inverter.
Then, with the other end of the 3-core cable wire up the plug socket. This is quite straightforward. Live to live (brown), neutral to neutral (blue), earth to earth (yellow/green).
You will likely be inserting the plug socket into a the plywood / tongue and groove wood in your van; you can use a jigsaw to easily cut out the shape of the plug socket and pop it into the cavity.
I hope you found this article on campervan inverters for campervans useful! Don't forget to subscribe to The Van Conversion Newsletter for everything you need to get started with your own van conversion (I'll send you a free wiring diagram when you sign up).
Be sure to check out the rest of the Electrics Guides. Related articles include: grounding electrics, leisure batteries, campervan electrics explained.
If you're converting a van but unsure of how to do it, you could also check out the Van Conversion Course on Udemy. In the course, you'll learn directly from me how to convert a van into your dream home - no prior experience needed!
Until next time,